diff --git a/commands/command_fetch.go b/commands/command_fetch.go
index d938da3b..e1fc12d0 100644
--- a/commands/command_fetch.go
+++ b/commands/command_fetch.go
@@ -105,7 +105,7 @@ func fetchCommand(cmd *cobra.Command, args []string) {
 	if !success {
 		c := getAPIClient()
 		e := c.Endpoints.Endpoint("download", cfg.CurrentRemote)
-		Exit("error: failed to push some objects to '%s'", e.Url)
+		Exit("error: failed to fetch some objects from '%s'", e.Url)
 	}
 }
 
diff --git a/commands/command_prune.go b/commands/command_prune.go
index e289b649..291219f9 100644
--- a/commands/command_prune.go
+++ b/commands/command_prune.go
@@ -13,6 +13,7 @@ import (
 	"github.com/git-lfs/git-lfs/localstorage"
 	"github.com/git-lfs/git-lfs/progress"
 	"github.com/git-lfs/git-lfs/tools"
+	"github.com/git-lfs/git-lfs/tools/humanize"
 	"github.com/git-lfs/git-lfs/tq"
 	"github.com/rubyist/tracerx"
 	"github.com/spf13/cobra"
@@ -142,7 +143,7 @@ func prune(fetchPruneConfig config.FetchPruneConfig, verifyRemote, dryRun, verbo
 			totalSize += file.Size
 			if verbose {
 				// Save up verbose output for the end, spinner still going
-				verboseOutput.WriteString(fmt.Sprintf(" * %v (%v)\n", file.Oid, humanizeBytes(file.Size)))
+				verboseOutput.WriteString(fmt.Sprintf(" * %v (%v)\n", file.Oid, humanize.FormatBytes(uint64(file.Size))))
 			}
 
 			if verifyRemote {
@@ -171,12 +172,12 @@ func prune(fetchPruneConfig config.FetchPruneConfig, verifyRemote, dryRun, verbo
 		return
 	}
 	if dryRun {
-		Print("%d files would be pruned (%v)", len(prunableObjects), humanizeBytes(totalSize))
+		Print("%d files would be pruned (%v)", len(prunableObjects), humanize.FormatBytes(uint64(totalSize)))
 		if verbose {
 			Print(verboseOutput.String())
 		}
 	} else {
-		Print("Pruning %d files, (%v)", len(prunableObjects), humanizeBytes(totalSize))
+		Print("Pruning %d files, (%v)", len(prunableObjects), humanize.FormatBytes(uint64(totalSize)))
 		if verbose {
 			Print(verboseOutput.String())
 		}
@@ -461,26 +462,6 @@ func pruneTaskGetReachableObjects(gitscanner *lfs.GitScanner, outObjectSet *tool
 	}
 }
 
-var byteUnits = []string{"B", "KB", "MB", "GB", "TB"}
-
-func humanizeBytes(bytes int64) string {
-	var output string
-	size := float64(bytes)
-
-	if bytes < 1024 {
-		return fmt.Sprintf("%d B", bytes)
-	}
-
-	for _, unit := range byteUnits {
-		if size < 1024.0 {
-			output = fmt.Sprintf("%3.1f %s", size, unit)
-			break
-		}
-		size /= 1024.0
-	}
-	return output
-}
-
 func init() {
 	RegisterCommand("prune", pruneCommand, func(cmd *cobra.Command) {
 		cmd.Flags().BoolVarP(&pruneDryRunArg, "dry-run", "d", false, "Don't delete anything, just report")
diff --git a/commands/command_pull.go b/commands/command_pull.go
index c2f7f22c..de4f56d5 100644
--- a/commands/command_pull.go
+++ b/commands/command_pull.go
@@ -113,7 +113,7 @@ func pull(remote string, filter *filepathfilter.Filter) {
 	if !success {
 		c := getAPIClient()
 		e := c.Endpoints.Endpoint("download", remote)
-		Exit("error: failed to push some objects to '%s'", e.Url)
+		Exit("error: failed to fetch some objects from '%s'", e.Url)
 	}
 }
 
diff --git a/commands/command_status.go b/commands/command_status.go
index 6bc38ac4..e74e26b5 100644
--- a/commands/command_status.go
+++ b/commands/command_status.go
@@ -2,6 +2,7 @@ package commands
 
 import (
 	"crypto/sha256"
+	"encoding/json"
 	"fmt"
 	"io"
 	"os"
@@ -14,7 +15,8 @@ import (
 )
 
 var (
-	porcelain = false
+	porcelain  = false
+	statusJson = false
 )
 
 func statusCommand(cmd *cobra.Command, args []string) {
@@ -31,6 +33,9 @@ func statusCommand(cmd *cobra.Command, args []string) {
 	if porcelain {
 		porcelainStagedPointers(scanIndexAt)
 		return
+	} else if statusJson {
+		jsonStagedPointers(scanIndexAt)
+		return
 	}
 
 	statusScanRefRange(ref)
@@ -224,6 +229,43 @@ func statusScanRefRange(ref *git.Ref) {
 
 }
 
+type JSONStatusEntry struct {
+	Status string `json:"status"`
+	From   string `json:"from,omitempty"`
+}
+
+type JSONStatus struct {
+	Files map[string]JSONStatusEntry `json:"files"`
+}
+
+func jsonStagedPointers(ref string) {
+	staged, unstaged, err := scanIndex(ref)
+	if err != nil {
+		ExitWithError(err)
+	}
+
+	status := JSONStatus{Files: make(map[string]JSONStatusEntry)}
+
+	for _, entry := range append(unstaged, staged...) {
+		switch entry.Status {
+		case lfs.StatusRename, lfs.StatusCopy:
+			status.Files[entry.DstName] = JSONStatusEntry{
+				Status: string(entry.Status), From: entry.SrcName,
+			}
+		default:
+			status.Files[entry.SrcName] = JSONStatusEntry{
+				Status: string(entry.Status),
+			}
+		}
+	}
+
+	ret, err := json.Marshal(status)
+	if err != nil {
+		ExitWithError(err)
+	}
+	Print(string(ret))
+}
+
 func porcelainStagedPointers(ref string) {
 	staged, unstaged, err := scanIndex(ref)
 	if err != nil {
@@ -260,5 +302,6 @@ func porcelainStatusLine(entry *lfs.DiffIndexEntry) string {
 func init() {
 	RegisterCommand("status", statusCommand, func(cmd *cobra.Command) {
 		cmd.Flags().BoolVarP(&porcelain, "porcelain", "p", false, "Give the output in an easy-to-parse format for scripts.")
+		cmd.Flags().BoolVarP(&statusJson, "json", "j", false, "Give the output in a stable json format for scripts.")
 	})
 }
diff --git a/docs/man/git-lfs-status.1.ronn b/docs/man/git-lfs-status.1.ronn
index 45b004a1..4fe533db 100644
--- a/docs/man/git-lfs-status.1.ronn
+++ b/docs/man/git-lfs-status.1.ronn
@@ -22,6 +22,8 @@ Display paths of Git LFS objects that
 
 * `--porcelain`:
     Give the output in an easy-to-parse format for scripts.
+* `--json`:
+    Give the output in a stable json format for scripts.
 
 ## SEE ALSO
 
diff --git a/errors/types.go b/errors/types.go
index e4fafd85..efeca36c 100644
--- a/errors/types.go
+++ b/errors/types.go
@@ -2,6 +2,7 @@ package errors
 
 import (
 	"fmt"
+	"net/url"
 
 	"github.com/pkg/errors"
 )
@@ -134,6 +135,9 @@ func IsRetriableError(err error) bool {
 	}); ok {
 		return e.RetriableError()
 	}
+	if cause, ok := Cause(err).(*url.Error); ok {
+		return cause.Temporary() || cause.Timeout()
+	}
 	if parent := parentOf(err); parent != nil {
 		return IsRetriableError(parent)
 	}
diff --git a/errors/types_test.go b/errors/types_test.go
new file mode 100644
index 00000000..a71ab9f1
--- /dev/null
+++ b/errors/types_test.go
@@ -0,0 +1,46 @@
+package errors_test
+
+import (
+	"net/url"
+	"testing"
+
+	"github.com/git-lfs/git-lfs/errors"
+	"github.com/stretchr/testify/assert"
+)
+
+type TemporaryError struct {
+}
+
+func (e TemporaryError) Error() string {
+	return ""
+}
+
+func (e TemporaryError) Temporary() bool {
+	return true
+}
+
+type TimeoutError struct {
+}
+
+func (e TimeoutError) Error() string {
+	return ""
+}
+
+func (e TimeoutError) Timeout() bool {
+	return true
+}
+
+func TestCanRetryOnTemporaryError(t *testing.T) {
+	err := &url.Error{Err: TemporaryError{}}
+	assert.True(t, errors.IsRetriableError(err))
+}
+
+func TestCanRetryOnTimeoutError(t *testing.T) {
+	err := &url.Error{Err: TimeoutError{}}
+	assert.True(t, errors.IsRetriableError(err))
+}
+
+func TestCannotRetryOnGenericUrlError(t *testing.T) {
+	err := &url.Error{Err: errors.New("")}
+	assert.False(t, errors.IsRetriableError(err))
+}
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/HEAD b/git/githistory/fixtures/linear-history-with-tags.git/HEAD
new file mode 100644
index 00000000..cb089cd8
--- /dev/null
+++ b/git/githistory/fixtures/linear-history-with-tags.git/HEAD
@@ -0,0 +1 @@
+ref: refs/heads/master
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/config b/git/githistory/fixtures/linear-history-with-tags.git/config
new file mode 100644
index 00000000..6c9406b7
--- /dev/null
+++ b/git/githistory/fixtures/linear-history-with-tags.git/config
@@ -0,0 +1,7 @@
+[core]
+	repositoryformatversion = 0
+	filemode = true
+	bare = false
+	logallrefupdates = true
+	ignorecase = true
+	precomposeunicode = true
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/index b/git/githistory/fixtures/linear-history-with-tags.git/index
new file mode 100644
index 00000000..f4668719
Binary files /dev/null and b/git/githistory/fixtures/linear-history-with-tags.git/index differ
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/logs/HEAD b/git/githistory/fixtures/linear-history-with-tags.git/logs/HEAD
new file mode 100644
index 00000000..7de3b66b
--- /dev/null
+++ b/git/githistory/fixtures/linear-history-with-tags.git/logs/HEAD
@@ -0,0 +1,3 @@
+0000000000000000000000000000000000000000 91b85be6928569390e937479509b80a1d0dccb0c Taylor Blau <me@ttaylorr.com> 1496954196 -0600	commit (initial): some.txt: a
+91b85be6928569390e937479509b80a1d0dccb0c 228afe30855933151f7a88e70d9d88314fd2f191 Taylor Blau <me@ttaylorr.com> 1496954207 -0600	commit: some.txt: b
+228afe30855933151f7a88e70d9d88314fd2f191 d941e4756add6b06f5bee766fcf669f55419f13f Taylor Blau <me@ttaylorr.com> 1496954214 -0600	commit: some.txt: c
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/logs/refs/heads/master b/git/githistory/fixtures/linear-history-with-tags.git/logs/refs/heads/master
new file mode 100644
index 00000000..7de3b66b
--- /dev/null
+++ b/git/githistory/fixtures/linear-history-with-tags.git/logs/refs/heads/master
@@ -0,0 +1,3 @@
+0000000000000000000000000000000000000000 91b85be6928569390e937479509b80a1d0dccb0c Taylor Blau <me@ttaylorr.com> 1496954196 -0600	commit (initial): some.txt: a
+91b85be6928569390e937479509b80a1d0dccb0c 228afe30855933151f7a88e70d9d88314fd2f191 Taylor Blau <me@ttaylorr.com> 1496954207 -0600	commit: some.txt: b
+228afe30855933151f7a88e70d9d88314fd2f191 d941e4756add6b06f5bee766fcf669f55419f13f Taylor Blau <me@ttaylorr.com> 1496954214 -0600	commit: some.txt: c
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/objects/20/ecedad3e74a113695fe5f00ab003694e2e1e9c b/git/githistory/fixtures/linear-history-with-tags.git/objects/20/ecedad3e74a113695fe5f00ab003694e2e1e9c
new file mode 100644
index 00000000..2033da03
Binary files /dev/null and b/git/githistory/fixtures/linear-history-with-tags.git/objects/20/ecedad3e74a113695fe5f00ab003694e2e1e9c differ
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/objects/22/8afe30855933151f7a88e70d9d88314fd2f191 b/git/githistory/fixtures/linear-history-with-tags.git/objects/22/8afe30855933151f7a88e70d9d88314fd2f191
new file mode 100644
index 00000000..fe0fd76b
Binary files /dev/null and b/git/githistory/fixtures/linear-history-with-tags.git/objects/22/8afe30855933151f7a88e70d9d88314fd2f191 differ
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/objects/2e/65efe2a145dda7ee51d1741299f848e5bf752e b/git/githistory/fixtures/linear-history-with-tags.git/objects/2e/65efe2a145dda7ee51d1741299f848e5bf752e
new file mode 100644
index 00000000..3e46ba4a
Binary files /dev/null and b/git/githistory/fixtures/linear-history-with-tags.git/objects/2e/65efe2a145dda7ee51d1741299f848e5bf752e differ
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/objects/34/10062ba67c5ed59b854387a8bc0ec012479368 b/git/githistory/fixtures/linear-history-with-tags.git/objects/34/10062ba67c5ed59b854387a8bc0ec012479368
new file mode 100644
index 00000000..75825102
Binary files /dev/null and b/git/githistory/fixtures/linear-history-with-tags.git/objects/34/10062ba67c5ed59b854387a8bc0ec012479368 differ
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/objects/3c/b3201d7942353fff5f45e03d114e8e7a061f87 b/git/githistory/fixtures/linear-history-with-tags.git/objects/3c/b3201d7942353fff5f45e03d114e8e7a061f87
new file mode 100644
index 00000000..01f148d9
Binary files /dev/null and b/git/githistory/fixtures/linear-history-with-tags.git/objects/3c/b3201d7942353fff5f45e03d114e8e7a061f87 differ
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/objects/52/a8963f48d54c7d352695a278ca4b025e130cb4 b/git/githistory/fixtures/linear-history-with-tags.git/objects/52/a8963f48d54c7d352695a278ca4b025e130cb4
new file mode 100644
index 00000000..08e48bcb
Binary files /dev/null and b/git/githistory/fixtures/linear-history-with-tags.git/objects/52/a8963f48d54c7d352695a278ca4b025e130cb4 differ
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/objects/63/d8dbd40c23542e740659a7168a0ce3138ea748 b/git/githistory/fixtures/linear-history-with-tags.git/objects/63/d8dbd40c23542e740659a7168a0ce3138ea748
new file mode 100644
index 00000000..f9051fff
Binary files /dev/null and b/git/githistory/fixtures/linear-history-with-tags.git/objects/63/d8dbd40c23542e740659a7168a0ce3138ea748 differ
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/objects/91/b85be6928569390e937479509b80a1d0dccb0c b/git/githistory/fixtures/linear-history-with-tags.git/objects/91/b85be6928569390e937479509b80a1d0dccb0c
new file mode 100644
index 00000000..7a6199bb
Binary files /dev/null and b/git/githistory/fixtures/linear-history-with-tags.git/objects/91/b85be6928569390e937479509b80a1d0dccb0c differ
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/objects/d9/41e4756add6b06f5bee766fcf669f55419f13f b/git/githistory/fixtures/linear-history-with-tags.git/objects/d9/41e4756add6b06f5bee766fcf669f55419f13f
new file mode 100644
index 00000000..e134799b
Binary files /dev/null and b/git/githistory/fixtures/linear-history-with-tags.git/objects/d9/41e4756add6b06f5bee766fcf669f55419f13f differ
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/refs/heads/master b/git/githistory/fixtures/linear-history-with-tags.git/refs/heads/master
new file mode 100644
index 00000000..35f2d5db
--- /dev/null
+++ b/git/githistory/fixtures/linear-history-with-tags.git/refs/heads/master
@@ -0,0 +1 @@
+d941e4756add6b06f5bee766fcf669f55419f13f
diff --git a/git/githistory/fixtures/linear-history-with-tags.git/refs/tags/middle b/git/githistory/fixtures/linear-history-with-tags.git/refs/tags/middle
new file mode 100644
index 00000000..5e7d4b25
--- /dev/null
+++ b/git/githistory/fixtures/linear-history-with-tags.git/refs/tags/middle
@@ -0,0 +1 @@
+228afe30855933151f7a88e70d9d88314fd2f191
diff --git a/git/githistory/rewriter.go b/git/githistory/rewriter.go
index 4952a317..e6e76259 100644
--- a/git/githistory/rewriter.go
+++ b/git/githistory/rewriter.go
@@ -35,10 +35,12 @@ type Rewriter struct {
 
 // RewriteOptions is an options type given to the Rewrite() function.
 type RewriteOptions struct {
-	// Left is the starting commit.
-	Left string
-	// Right is the ending commit.
-	Right string
+	// Include is the list of refs of which commits reachable by that ref
+	// will be included.
+	Include []string
+	// Exclude is the list of refs of which commits reachable by that ref
+	// will be excluded.
+	Exclude []string
 
 	// BlobFn specifies a function to rewrite blobs.
 	//
@@ -142,9 +144,8 @@ func NewRewriter(db *odb.ObjectDatabase, opts ...rewriterOption) *Rewriter {
 // Rewrite rewrites the range of commits given by *RewriteOptions.{Left,Right}
 // using the BlobRewriteFn to rewrite the individual blobs.
 func (r *Rewriter) Rewrite(opt *RewriteOptions) ([]byte, error) {
-	// First, construct a scanner to iterate through the range of commits to
-	// rewrite.
-	scanner, err := git.NewRevListScanner(opt.Left, opt.Right, r.scannerOpts())
+	// First, obtain a list of commits to rewrite.
+	commits, err := r.commitsToMigrate(opt)
 	if err != nil {
 		return nil, err
 	}
@@ -152,10 +153,10 @@ func (r *Rewriter) Rewrite(opt *RewriteOptions) ([]byte, error) {
 	// Keep track of the last commit that we rewrote. Callers often want
 	// this so that they can perform a git-update-ref(1).
 	var tip []byte
-	for scanner.Scan() {
+	for _, oid := range commits {
 		// Load the original commit to access the data necessary in
 		// order to rewrite it.
-		original, err := r.db.Commit(scanner.OID())
+		original, err := r.db.Commit(oid)
 		if err != nil {
 			return nil, err
 		}
@@ -172,11 +173,24 @@ func (r *Rewriter) Rewrite(opt *RewriteOptions) ([]byte, error) {
 		//
 		// This operation is safe since we are visiting the commits in
 		// reverse topological order and therefore have seen all parents
-		// before children (in other words, r.uncacheCommit(parent) will
-		// always return a value).
+		// before children (in other words, r.uncacheCommit(...) will
+		// always return a value, if the prospective parent is a part of
+		// the migration).
 		rewrittenParents := make([][]byte, 0, len(original.ParentIDs))
-		for _, parent := range original.ParentIDs {
-			rewrittenParents = append(rewrittenParents, r.uncacheCommit(parent))
+		for _, originalParent := range original.ParentIDs {
+			rewrittenParent, ok := r.uncacheCommit(originalParent)
+			if !ok {
+				// If we haven't seen the parent before, this
+				// means that we're doing a partial migration
+				// and the parent that we're looking for isn't
+				// included.
+				//
+				// Use the original parent to properly link
+				// history across the migration boundary.
+				rewrittenParent = originalParent
+			}
+
+			rewrittenParents = append(rewrittenParents, rewrittenParent)
 		}
 
 		// Construct a new commit using the original header information,
@@ -196,15 +210,11 @@ func (r *Rewriter) Rewrite(opt *RewriteOptions) ([]byte, error) {
 
 		// Cache that commit so that we can reassign children of this
 		// commit.
-		r.cacheCommit(scanner.OID(), rewrittenCommit)
+		r.cacheCommit(oid, rewrittenCommit)
 
 		// Move the tip forward.
 		tip = rewrittenCommit
 	}
-
-	if err = scanner.Err(); err != nil {
-		return nil, err
-	}
 	return tip, err
 }
 
@@ -304,6 +314,32 @@ func (r *Rewriter) rewriteBlob(from []byte, path string, fn BlobRewriteFn) ([]by
 	return sha, nil
 }
 
+// commitsToMigrate returns an in-memory copy of a list of commits according to
+// the output of git-rev-list(1) (given the *RewriteOptions), where each
+// outputted commit is 20 bytes of raw SHA1.
+//
+// If any error was encountered, it will be returned.
+func (r *Rewriter) commitsToMigrate(opt *RewriteOptions) ([][]byte, error) {
+	scanner, err := git.NewRevListScanner(
+		opt.Include, opt.Exclude, r.scannerOpts())
+	if err != nil {
+		return nil, err
+	}
+
+	var commits [][]byte
+	for scanner.Scan() {
+		commits = append(commits, scanner.OID())
+	}
+
+	if err = scanner.Err(); err != nil {
+		return nil, err
+	}
+	if err = scanner.Close(); err != nil {
+		return nil, err
+	}
+	return commits, nil
+}
+
 // scannerOpts returns a *git.ScanRefsOptions instance to be given to the
 // *git.RevListScanner.
 //
@@ -364,10 +400,12 @@ func (r *Rewriter) cacheCommit(from, to []byte) {
 
 // uncacheCommit returns a *git/odb.Commit that is cached from the given
 // *git/odb.Commit "from". That is to say, it returns the *git/odb.Commit that
-// "from" should be rewritten to, or nil if none could be found.
-func (r *Rewriter) uncacheCommit(from []byte) []byte {
+// "from" should be rewritten to and true, or nil and false if none could be
+// found.
+func (r *Rewriter) uncacheCommit(from []byte) ([]byte, bool) {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 
-	return r.commits[hex.EncodeToString(from)]
+	c, ok := r.commits[hex.EncodeToString(from)]
+	return c, ok
 }
diff --git a/git/githistory/rewriter_test.go b/git/githistory/rewriter_test.go
index b5b413a6..08ce23ba 100644
--- a/git/githistory/rewriter_test.go
+++ b/git/githistory/rewriter_test.go
@@ -19,7 +19,7 @@ func TestRewriterRewritesHistory(t *testing.T) {
 	db := DatabaseFromFixture(t, "linear-history.git")
 	r := NewRewriter(db)
 
-	tip, err := r.Rewrite(&RewriteOptions{Left: "master",
+	tip, err := r.Rewrite(&RewriteOptions{Include: []string{"refs/heads/master"},
 		BlobFn: func(path string, b *odb.Blob) (*odb.Blob, error) {
 			contents, err := ioutil.ReadAll(b.Contents)
 			if err != nil {
@@ -80,7 +80,7 @@ func TestRewriterRewritesOctopusMerges(t *testing.T) {
 	db := DatabaseFromFixture(t, "octopus-merge.git")
 	r := NewRewriter(db)
 
-	tip, err := r.Rewrite(&RewriteOptions{Left: "master",
+	tip, err := r.Rewrite(&RewriteOptions{Include: []string{"refs/heads/master"},
 		BlobFn: func(path string, b *odb.Blob) (*odb.Blob, error) {
 			return &odb.Blob{
 				Contents: io.MultiReader(b.Contents, strings.NewReader("_new")),
@@ -127,7 +127,7 @@ func TestRewriterDoesntVisitUnchangedSubtrees(t *testing.T) {
 
 	seen := make(map[string]int)
 
-	_, err := r.Rewrite(&RewriteOptions{Left: "master",
+	_, err := r.Rewrite(&RewriteOptions{Include: []string{"refs/heads/master"},
 		BlobFn: func(path string, b *odb.Blob) (*odb.Blob, error) {
 			seen[path] = seen[path] + 1
 
@@ -145,7 +145,7 @@ func TestRewriterVisitsUniqueEntriesWithIdenticalContents(t *testing.T) {
 	db := DatabaseFromFixture(t, "identical-blobs.git")
 	r := NewRewriter(db)
 
-	tip, err := r.Rewrite(&RewriteOptions{Left: "master",
+	tip, err := r.Rewrite(&RewriteOptions{Include: []string{"refs/heads/master"},
 		BlobFn: func(path string, b *odb.Blob) (*odb.Blob, error) {
 			if path == root("b.txt") {
 				return b, nil
@@ -185,7 +185,7 @@ func TestRewriterIgnoresPathsThatDontMatchFilter(t *testing.T) {
 
 	seen := make(map[string]int)
 
-	_, err := r.Rewrite(&RewriteOptions{Left: "master",
+	_, err := r.Rewrite(&RewriteOptions{Include: []string{"refs/heads/master"},
 		BlobFn: func(path string, b *odb.Blob) (*odb.Blob, error) {
 			seen[path] = seen[path] + 1
 
@@ -208,7 +208,7 @@ func TestRewriterAllowsAdditionalTreeEntries(t *testing.T) {
 	})
 	assert.Nil(t, err)
 
-	tip, err := r.Rewrite(&RewriteOptions{Left: "master",
+	tip, err := r.Rewrite(&RewriteOptions{Include: []string{"refs/heads/master"},
 		BlobFn: func(path string, b *odb.Blob) (*odb.Blob, error) {
 			return b, nil
 		},
@@ -266,6 +266,39 @@ func TestRewriterAllowsAdditionalTreeEntries(t *testing.T) {
 	AssertBlobContents(t, db, tree3, "extra.txt", "extra\n")
 }
 
+func TestHistoryRewriterUseOriginalParentsForPartialMigration(t *testing.T) {
+	db := DatabaseFromFixture(t, "linear-history-with-tags.git")
+	r := NewRewriter(db)
+
+	tip, err := r.Rewrite(&RewriteOptions{
+		Include: []string{"refs/heads/master"},
+		Exclude: []string{"refs/tags/middle"},
+
+		BlobFn: func(path string, b *odb.Blob) (*odb.Blob, error) {
+			return b, nil
+		},
+	})
+
+	// After rewriting, the rewriter should have only modified the latest
+	// commit (HEAD), and excluded the first two, both reachable by
+	// refs/tags/middle.
+	//
+	// This should modify one commit, and appropriately link the parent as
+	// follows:
+	//
+	//   tree 20ecedad3e74a113695fe5f00ab003694e2e1e9c
+	//   parent 228afe30855933151f7a88e70d9d88314fd2f191
+	//   author Taylor Blau <me@ttaylorr.com> 1496954214 -0600
+	//   committer Taylor Blau <me@ttaylorr.com> 1496954214 -0600
+	//
+	//   some.txt: c
+
+	expectedParent := "228afe30855933151f7a88e70d9d88314fd2f191"
+
+	assert.NoError(t, err)
+	AssertCommitParent(t, db, hex.EncodeToString(tip), expectedParent)
+}
+
 func root(path string) string {
 	if !strings.HasPrefix(path, string(os.PathSeparator)) {
 		path = string(os.PathSeparator) + path
diff --git a/git/odb/commit.go b/git/odb/commit.go
index a48af358..080a9f24 100644
--- a/git/odb/commit.go
+++ b/git/odb/commit.go
@@ -104,13 +104,11 @@ func (c *Commit) Decode(from io.Reader, size int64) (n int, err error) {
 			continue
 		}
 
-		fields := strings.Fields(text)
-		if len(fields) > 0 {
+		if fields := strings.Fields(text); len(fields) > 0 && !finishedHeaders {
 			switch fields[0] {
 			case "tree":
 				id, err := hex.DecodeString(fields[1])
 				if err != nil {
-					panic(1)
 					return n, err
 				}
 				c.TreeID = id
@@ -125,15 +123,13 @@ func (c *Commit) Decode(from io.Reader, size int64) (n int, err error) {
 			case "committer":
 				c.Committer = strings.Join(fields[1:], " ")
 			default:
-				if finishedHeaders {
-					messageParts = append(messageParts, s.Text())
-				} else {
-					c.ExtraHeaders = append(c.ExtraHeaders, &ExtraHeader{
-						K: fields[0],
-						V: strings.Join(fields[1:], " "),
-					})
-				}
+				c.ExtraHeaders = append(c.ExtraHeaders, &ExtraHeader{
+					K: fields[0],
+					V: strings.Join(fields[1:], " "),
+				})
 			}
+		} else {
+			messageParts = append(messageParts, s.Text())
 		}
 	}
 
diff --git a/git/odb/commit_test.go b/git/odb/commit_test.go
index 2990cf28..3358ce6d 100644
--- a/git/odb/commit_test.go
+++ b/git/odb/commit_test.go
@@ -83,6 +83,33 @@ func TestCommitDecoding(t *testing.T) {
 	assert.Equal(t, "initial commit", commit.Message)
 }
 
+func TestCommitDecodingWithMessageKeywordPrefix(t *testing.T) {
+	author := &Signature{Name: "John Doe", Email: "john@example.com", When: time.Now()}
+	committer := &Signature{Name: "Jane Doe", Email: "jane@example.com", When: time.Now()}
+
+	treeId := []byte("aaaaaaaaaaaaaaaaaaaa")
+	treeIdAscii := hex.EncodeToString(treeId)
+
+	from := new(bytes.Buffer)
+	fmt.Fprintf(from, "author %s\n", author)
+	fmt.Fprintf(from, "committer %s\n", committer)
+	fmt.Fprintf(from, "tree %s\n", hex.EncodeToString(treeId))
+	fmt.Fprintf(from, "\ntree <- initial commit\n")
+
+	flen := from.Len()
+
+	commit := new(Commit)
+	n, err := commit.Decode(from, int64(flen))
+
+	assert.NoError(t, err)
+	assert.Equal(t, flen, n)
+
+	assert.Equal(t, author.String(), commit.Author)
+	assert.Equal(t, committer.String(), commit.Committer)
+	assert.Equal(t, treeIdAscii, hex.EncodeToString(commit.TreeID))
+	assert.Equal(t, "tree <- initial commit", commit.Message)
+}
+
 func assertLine(t *testing.T, buf *bytes.Buffer, wanted string, args ...interface{}) {
 	got, err := buf.ReadString('\n')
 
diff --git a/git/odb/tree.go b/git/odb/tree.go
index 10c71301..66aa09f7 100644
--- a/git/odb/tree.go
+++ b/git/odb/tree.go
@@ -50,7 +50,7 @@ func (t *Tree) Decode(from io.Reader, size int64) (n int, err error) {
 		fname = strings.TrimSuffix(fname, "\x00")
 
 		var sha [20]byte
-		if _, err = buf.Read(sha[:]); err != nil {
+		if _, err = io.ReadFull(buf, sha[:]); err != nil {
 			return n, err
 		}
 		n += 20
diff --git a/git/odb/tree_test.go b/git/odb/tree_test.go
index bdbf02f2..6c51eb1e 100644
--- a/git/odb/tree_test.go
+++ b/git/odb/tree_test.go
@@ -1,6 +1,7 @@
 package odb
 
 import (
+	"bufio"
 	"bytes"
 	"fmt"
 	"strconv"
@@ -101,6 +102,30 @@ func TestTreeDecoding(t *testing.T) {
 	}, tree.Entries[3])
 }
 
+func TestTreeDecodingShaBoundary(t *testing.T) {
+	var from bytes.Buffer
+
+	fmt.Fprintf(&from, "%s %s\x00%s",
+		strconv.FormatInt(int64(0100644), 8),
+		"a.dat", []byte("aaaaaaaaaaaaaaaaaaaa"))
+
+	flen := from.Len()
+
+	tree := new(Tree)
+	n, err := tree.Decode(bufio.NewReaderSize(&from, flen-2), int64(flen))
+
+	assert.Nil(t, err)
+	assert.Equal(t, flen, n)
+
+	require.Len(t, tree.Entries, 1)
+	assert.Equal(t, &TreeEntry{
+		Name:     "a.dat",
+		Type:     BlobObjectType,
+		Oid:      []byte("aaaaaaaaaaaaaaaaaaaa"),
+		Filemode: 0100644,
+	}, tree.Entries[0])
+}
+
 func assertTreeEntry(t *testing.T, buf *bytes.Buffer,
 	name string, typ ObjectType, oid []byte, mode int32) {
 
diff --git a/git/rev_list_scanner.go b/git/rev_list_scanner.go
index d64c3188..d225e4bf 100644
--- a/git/rev_list_scanner.go
+++ b/git/rev_list_scanner.go
@@ -24,8 +24,8 @@ const (
 	ScanRefsMode ScanningMode = iota
 	// ScanAllMode will scan all history.
 	ScanAllMode
-	// ScanLeftToRemoteMode will scan the difference between "left" and a
-	// remote tracking ref.
+	// ScanLeftToRemoteMode will scan the difference between any included
+	// SHA1s and a remote tracking ref.
 	ScanLeftToRemoteMode
 )
 
@@ -160,15 +160,15 @@ var (
 	z40 = regexp.MustCompile(`\^?0{40}`)
 )
 
-// NewRevListScanner instantiates a new RevListScanner instance scanning between
-// the "left" and "right" commitish (commit, refspec) and scanning using the
-// *ScanRefsOptions "opt" configuration.
+// NewRevListScanner instantiates a new RevListScanner instance scanning all
+// revisions reachable by refs contained in "include" and not reachable by any
+// refs included in "excluded", using the *ScanRefsOptions "opt" configuration.
 //
 // It returns a new *RevListScanner instance, or an error if one was
 // encountered. Upon returning, the `git-rev-list(1)` instance is already
 // running, and Scan() may be called immediately.
-func NewRevListScanner(left, right string, opt *ScanRefsOptions) (*RevListScanner, error) {
-	stdin, args, err := revListArgs(left, right, opt)
+func NewRevListScanner(include, excluded []string, opt *ScanRefsOptions) (*RevListScanner, error) {
+	stdin, args, err := revListArgs(include, excluded, opt)
 	if err != nil {
 		return nil, err
 	}
@@ -218,13 +218,13 @@ func NewRevListScanner(left, right string, opt *ScanRefsOptions) (*RevListScanne
 	}, nil
 }
 
-// revListArgs returns the arguments for a given left, right, and
-// ScanRefsOptions instance.
+// revListArgs returns the arguments for a given included and excluded set of
+// SHA1s, and ScanRefsOptions instance.
 //
 // In order, it returns the contents of stdin as an io.Reader, the args passed
 // to git as a []string, and any error encountered in generating those if one
 // occurred.
-func revListArgs(l, r string, opt *ScanRefsOptions) (io.Reader, []string, error) {
+func revListArgs(include, exclude []string, opt *ScanRefsOptions) (io.Reader, []string, error) {
 	var stdin io.Reader
 	args := []string{"rev-list"}
 	if !opt.CommitsOnly {
@@ -247,19 +247,17 @@ func revListArgs(l, r string, opt *ScanRefsOptions) (io.Reader, []string, error)
 			args = append(args, "--do-walk")
 		}
 
-		args = append(args, l)
-		if len(r) > 0 && !z40.MatchString(r) {
-			args = append(args, r)
-		}
+		args = append(args, includeExcludeShas(include, exclude)...)
 	case ScanAllMode:
 		args = append(args, "--all")
 	case ScanLeftToRemoteMode:
 		if len(opt.SkippedRefs) == 0 {
-			args = append(args, l, "--not", "--remotes="+opt.Remote)
+			args = append(args, includeExcludeShas(include, exclude)...)
+			args = append(args, "--not", "--remotes="+opt.Remote)
 		} else {
 			args = append(args, "--stdin")
 			stdin = strings.NewReader(strings.Join(
-				append([]string{l}, opt.SkippedRefs...), "\n"),
+				append(includeExcludeShas(include, exclude), opt.SkippedRefs...), "\n"),
 			)
 		}
 	default:
@@ -268,6 +266,34 @@ func revListArgs(l, r string, opt *ScanRefsOptions) (io.Reader, []string, error)
 	return stdin, append(args, "--"), nil
 }
 
+func includeExcludeShas(include, exclude []string) []string {
+	include = nonZeroShas(include)
+	exclude = nonZeroShas(exclude)
+
+	args := make([]string, 0, len(include)+len(exclude))
+
+	for _, i := range include {
+		args = append(args, i)
+	}
+
+	for _, x := range exclude {
+		args = append(args, fmt.Sprintf("^%s", x))
+	}
+
+	return args
+}
+
+func nonZeroShas(all []string) []string {
+	nz := make([]string, 0, len(all))
+
+	for _, sha := range all {
+		if len(sha) > 0 && !z40.MatchString(sha) {
+			nz = append(nz, sha)
+		}
+	}
+	return nz
+}
+
 // Name is an optional field that gives the name of the object (if the object is
 // a tree, blob).
 //
diff --git a/git/rev_list_scanner_test.go b/git/rev_list_scanner_test.go
index 02dfff52..ab29417c 100644
--- a/git/rev_list_scanner_test.go
+++ b/git/rev_list_scanner_test.go
@@ -14,9 +14,9 @@ import (
 )
 
 type ArgsTestCase struct {
-	Left  string
-	Right string
-	Opt   *ScanRefsOptions
+	Include []string
+	Exclude []string
+	Opt     *ScanRefsOptions
 
 	ExpectedStdin string
 	ExpectedArgs  []string
@@ -24,7 +24,7 @@ type ArgsTestCase struct {
 }
 
 func (c *ArgsTestCase) Assert(t *testing.T) {
-	stdin, args, err := revListArgs(c.Left, c.Right, c.Opt)
+	stdin, args, err := revListArgs(c.Include, c.Exclude, c.Opt)
 
 	if len(c.ExpectedErr) > 0 {
 		assert.EqualError(t, err, c.ExpectedErr)
@@ -48,99 +48,104 @@ func (c *ArgsTestCase) Assert(t *testing.T) {
 	}
 }
 
+var (
+	s1 = "decafdecafdecafdecafdecafdecafdecafdecaf"
+	s2 = "cafecafecafecafecafecafecafecafecafecafe"
+)
+
 func TestRevListArgs(t *testing.T) {
 	for desc, c := range map[string]*ArgsTestCase{
 		"scan refs deleted, left and right": {
-			Left: "left", Right: "right", Opt: &ScanRefsOptions{
+			Include: []string{s1}, Exclude: []string{s2}, Opt: &ScanRefsOptions{
 				Mode:             ScanRefsMode,
 				SkipDeletedBlobs: false,
 			},
-			ExpectedArgs: []string{"rev-list", "--objects", "--do-walk", "left", "right", "--"},
+			ExpectedArgs: []string{"rev-list", "--objects", "--do-walk", s1, "^" + s2, "--"},
 		},
 		"scan refs not deleted, left and right": {
-			Left: "left", Right: "right", Opt: &ScanRefsOptions{
+			Include: []string{s1}, Exclude: []string{s2}, Opt: &ScanRefsOptions{
 				Mode:             ScanRefsMode,
 				SkipDeletedBlobs: true,
 			},
-			ExpectedArgs: []string{"rev-list", "--objects", "--no-walk", "left", "right", "--"},
+			ExpectedArgs: []string{"rev-list", "--objects", "--no-walk", s1, "^" + s2, "--"},
 		},
 		"scan refs deleted, left only": {
-			Left: "left", Right: "", Opt: &ScanRefsOptions{
+			Include: []string{s1}, Opt: &ScanRefsOptions{
 				Mode:             ScanRefsMode,
 				SkipDeletedBlobs: false,
 			},
-			ExpectedArgs: []string{"rev-list", "--objects", "--do-walk", "left", "--"},
+			ExpectedArgs: []string{"rev-list", "--objects", "--do-walk", s1, "--"},
 		},
 		"scan refs not deleted, left only": {
-			Left: "left", Right: "", Opt: &ScanRefsOptions{
+			Include: []string{s1}, Opt: &ScanRefsOptions{
 				Mode:             ScanRefsMode,
 				SkipDeletedBlobs: true,
 			},
-			ExpectedArgs: []string{"rev-list", "--objects", "--no-walk", "left", "--"},
+			ExpectedArgs: []string{"rev-list", "--objects", "--no-walk", s1, "--"},
 		},
 		"scan all": {
-			Left: "left", Right: "right", Opt: &ScanRefsOptions{
+			Include: []string{s1}, Exclude: []string{s2}, Opt: &ScanRefsOptions{
 				Mode: ScanAllMode,
 			},
 			ExpectedArgs: []string{"rev-list", "--objects", "--all", "--"},
 		},
 		"scan left to remote, no skipped refs": {
-			Left: "left", Right: "right", Opt: &ScanRefsOptions{
+			Include: []string{s1}, Opt: &ScanRefsOptions{
 				Mode:        ScanLeftToRemoteMode,
 				Remote:      "origin",
 				SkippedRefs: []string{},
 			},
-			ExpectedArgs: []string{"rev-list", "--objects", "left", "--not", "--remotes=origin", "--"},
+			ExpectedArgs: []string{"rev-list", "--objects", s1, "--not", "--remotes=origin", "--"},
 		},
 		"scan left to remote, skipped refs": {
-			Left: "left", Right: "right", Opt: &ScanRefsOptions{
+			Include: []string{s1}, Exclude: []string{s2}, Opt: &ScanRefsOptions{
 				Mode:        ScanLeftToRemoteMode,
 				Remote:      "origin",
 				SkippedRefs: []string{"a", "b", "c"},
 			},
 			ExpectedArgs:  []string{"rev-list", "--objects", "--stdin", "--"},
-			ExpectedStdin: "left\na\nb\nc",
+			ExpectedStdin: s1 + "\n^" + s2 + "\na\nb\nc",
 		},
 		"scan unknown type": {
-			Left: "left", Right: "right", Opt: &ScanRefsOptions{
+			Include: []string{s1}, Exclude: []string{s2}, Opt: &ScanRefsOptions{
 				Mode: ScanningMode(-1),
 			},
 			ExpectedErr: "unknown scan type: -1",
 		},
 		"scan date order": {
-			Left: "left", Right: "right", Opt: &ScanRefsOptions{
+			Include: []string{s1}, Exclude: []string{s2}, Opt: &ScanRefsOptions{
 				Mode:  ScanRefsMode,
 				Order: DateRevListOrder,
 			},
-			ExpectedArgs: []string{"rev-list", "--objects", "--date-order", "--do-walk", "left", "right", "--"},
+			ExpectedArgs: []string{"rev-list", "--objects", "--date-order", "--do-walk", s1, "^" + s2, "--"},
 		},
 		"scan author date order": {
-			Left: "left", Right: "right", Opt: &ScanRefsOptions{
+			Include: []string{s1}, Exclude: []string{s2}, Opt: &ScanRefsOptions{
 				Mode:  ScanRefsMode,
 				Order: AuthorDateRevListOrder,
 			},
-			ExpectedArgs: []string{"rev-list", "--objects", "--author-date-order", "--do-walk", "left", "right", "--"},
+			ExpectedArgs: []string{"rev-list", "--objects", "--author-date-order", "--do-walk", s1, "^" + s2, "--"},
 		},
 		"scan topo order": {
-			Left: "left", Right: "right", Opt: &ScanRefsOptions{
+			Include: []string{s1}, Exclude: []string{s2}, Opt: &ScanRefsOptions{
 				Mode:  ScanRefsMode,
 				Order: TopoRevListOrder,
 			},
-			ExpectedArgs: []string{"rev-list", "--objects", "--topo-order", "--do-walk", "left", "right", "--"},
+			ExpectedArgs: []string{"rev-list", "--objects", "--topo-order", "--do-walk", s1, "^" + s2, "--"},
 		},
 		"scan commits only": {
-			Left: "left", Right: "right", Opt: &ScanRefsOptions{
+			Include: []string{s1}, Exclude: []string{s2}, Opt: &ScanRefsOptions{
 				Mode:        ScanRefsMode,
 				CommitsOnly: true,
 			},
-			ExpectedArgs: []string{"rev-list", "--do-walk", "left", "right", "--"},
+			ExpectedArgs: []string{"rev-list", "--do-walk", s1, "^" + s2, "--"},
 		},
 		"scan reverse": {
-			Left: "left", Right: "right", Opt: &ScanRefsOptions{
+			Include: []string{s1}, Exclude: []string{s2}, Opt: &ScanRefsOptions{
 				Mode:    ScanRefsMode,
 				Reverse: true,
 			},
-			ExpectedArgs: []string{"rev-list", "--objects", "--reverse", "--do-walk", "left", "right", "--"},
+			ExpectedArgs: []string{"rev-list", "--objects", "--reverse", "--do-walk", s1, "^" + s2, "--"},
 		},
 	} {
 		t.Run(desc, c.Assert)
diff --git a/lfs/gitscanner_refs.go b/lfs/gitscanner_refs.go
index d3b20e05..dca86745 100644
--- a/lfs/gitscanner_refs.go
+++ b/lfs/gitscanner_refs.go
@@ -41,7 +41,7 @@ func scanRefsToChan(scanner *GitScanner, pointerCb GitScannerFoundPointer, refLe
 		panic("no scan ref options")
 	}
 
-	revs, err := revListShas(refLeft, refRight, opt)
+	revs, err := revListShas([]string{refLeft, refRight}, nil, opt)
 	if err != nil {
 		return err
 	}
@@ -89,8 +89,8 @@ func scanRefsToChan(scanner *GitScanner, pointerCb GitScannerFoundPointer, refLe
 // revListShas uses git rev-list to return the list of object sha1s
 // for the given ref. If all is true, ref is ignored. It returns a
 // channel from which sha1 strings can be read.
-func revListShas(refLeft, refRight string, opt *ScanRefsOptions) (*StringChannelWrapper, error) {
-	scanner, err := git.NewRevListScanner(refLeft, refRight, &git.ScanRefsOptions{
+func revListShas(include, exclude []string, opt *ScanRefsOptions) (*StringChannelWrapper, error) {
+	scanner, err := git.NewRevListScanner(include, exclude, &git.ScanRefsOptions{
 		Mode:             git.ScanningMode(opt.ScanMode),
 		Remote:           opt.RemoteName,
 		SkipDeletedBlobs: opt.SkipDeletedBlobs,
diff --git a/test/test-status.sh b/test/test-status.sh
index 7c5e3b66..263a9447 100755
--- a/test/test-status.sh
+++ b/test/test-status.sh
@@ -85,6 +85,32 @@ A  file2.dat"
 )
 end_test
 
+begin_test "status --json"
+(
+  set -e
+
+  mkdir repo-3
+  cd repo-3
+  git init
+  git lfs track "*.dat"
+  echo "some data" > file1.dat
+  git add file1.dat
+  git commit -m "file1.dat"
+
+  echo "other data" > file1.dat
+
+  expected='{"files":{"file1.dat":{"status":"M"}}}'
+  [ "$expected" = "$(git lfs status --json)" ]
+
+  git add file1.dat
+  git commit -m "file1.dat changed"
+  git mv file1.dat file2.dat
+
+  expected='{"files":{"file2.dat":{"status":"R","from":"file1.dat"}}}'
+  [ "$expected" = "$(git lfs status --json)" ]
+)
+end_test
+
 
 begin_test "status: outside git repository"
 (
diff --git a/tools/humanize/humanize.go b/tools/humanize/humanize.go
new file mode 100644
index 00000000..82895af1
--- /dev/null
+++ b/tools/humanize/humanize.go
@@ -0,0 +1,97 @@
+package humanize
+
+import (
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+	"unicode"
+
+	"github.com/git-lfs/git-lfs/errors"
+)
+
+const (
+	Byte = 1 << (iota * 10)
+	Kibibyte
+	Mebibyte
+	Gibibyte
+	Tebibyte
+	Pebibyte
+
+	Kilobyte = 1000 * Byte
+	Megabyte = 1000 * Kilobyte
+	Gigabyte = 1000 * Megabyte
+	Terabyte = 1000 * Gigabyte
+	Petabyte = 1000 * Terabyte
+)
+
+var bytesTable = map[string]uint64{
+	"b": Byte,
+
+	"kib": Kibibyte,
+	"mib": Mebibyte,
+	"gib": Gibibyte,
+	"tib": Tebibyte,
+	"pib": Pebibyte,
+
+	"kb": Kilobyte,
+	"mb": Megabyte,
+	"gb": Gigabyte,
+	"tb": Terabyte,
+	"pb": Petabyte,
+}
+
+// ParseBytes parses a given human-readable bytes or ibytes string into a number
+// of bytes, or an error if the string was unable to be parsed.
+func ParseBytes(str string) (uint64, error) {
+	var sep int
+	for _, r := range str {
+		if !(unicode.IsDigit(r) || r == '.' || r == ',') {
+			break
+		}
+
+		sep = sep + 1
+	}
+
+	f, err := strconv.ParseFloat(strings.Replace(str[:sep], ",", "", -1), 64)
+	if err != nil {
+		return 0, err
+	}
+
+	unit := strings.ToLower(strings.TrimSpace(str[sep:]))
+
+	if m, ok := bytesTable[unit]; ok {
+		f = f * float64(m)
+		if f >= math.MaxUint64 {
+			return 0, errors.New("number of bytes too large")
+		}
+		return uint64(f), nil
+	}
+	return 0, errors.Errorf("unknown unit: %q", unit)
+}
+
+var sizes = []string{"B", "KB", "MB", "GB", "TB", "PB"}
+
+// FormatBytes outputs the given number of bytes "s" as a human-readable string,
+// rounding to the nearest half within .01.
+func FormatBytes(s uint64) string {
+	if s < 10 {
+		return fmt.Sprintf("%d B", s)
+	}
+
+	e := math.Floor(log(float64(s), 1000))
+	suffix := sizes[int(e)]
+
+	val := math.Floor(float64(s)/math.Pow(1000, e)*10+.5) / 10
+	f := "%.0f %s"
+	if val < 10 {
+		f = "%.1f %s"
+	}
+
+	return fmt.Sprintf(f, val, suffix)
+}
+
+// log takes the log base "b" of "n" (\log_b{n})
+func log(n, b float64) float64 {
+	return math.Log(n) / math.Log(b)
+}
diff --git a/tools/humanize/humanize_test.go b/tools/humanize/humanize_test.go
new file mode 100644
index 00000000..60291d41
--- /dev/null
+++ b/tools/humanize/humanize_test.go
@@ -0,0 +1,123 @@
+package humanize_test
+
+import (
+	"math"
+	"testing"
+
+	"github.com/git-lfs/git-lfs/tools/humanize"
+	"github.com/stretchr/testify/assert"
+)
+
+type ParseBytesTestCase struct {
+	Given    string
+	Expected uint64
+	Err      error
+}
+
+func (c *ParseBytesTestCase) Assert(t *testing.T) {
+	got, err := humanize.ParseBytes(c.Given)
+	if c.Err == nil {
+		assert.NoError(t, err, "unexpected error: %s", err)
+		assert.EqualValues(t, c.Expected, got)
+	} else {
+		assert.Equal(t, c.Err, err)
+	}
+}
+
+type FormatBytesTestCase struct {
+	Given    uint64
+	Expected string
+}
+
+func (c *FormatBytesTestCase) Assert(t *testing.T) {
+	assert.Equal(t, c.Expected, humanize.FormatBytes(c.Given))
+}
+
+func TestParseBytes(t *testing.T) {
+	for desc, c := range map[string]*ParseBytesTestCase{
+		"parse byte":     {"10B", uint64(10 * math.Pow(2, 0)), nil},
+		"parse kibibyte": {"20KIB", uint64(20 * math.Pow(2, 10)), nil},
+		"parse mebibyte": {"30MIB", uint64(30 * math.Pow(2, 20)), nil},
+		"parse gibibyte": {"40GIB", uint64(40 * math.Pow(2, 30)), nil},
+		"parse tebibyte": {"50TIB", uint64(50 * math.Pow(2, 40)), nil},
+		"parse pebibyte": {"60PIB", uint64(60 * math.Pow(2, 50)), nil},
+
+		"parse byte (lowercase)":     {"10b", uint64(10 * math.Pow(2, 0)), nil},
+		"parse kibibyte (lowercase)": {"20kib", uint64(20 * math.Pow(2, 10)), nil},
+		"parse mebibyte (lowercase)": {"30mib", uint64(30 * math.Pow(2, 20)), nil},
+		"parse gibibyte (lowercase)": {"40gib", uint64(40 * math.Pow(2, 30)), nil},
+		"parse tebibyte (lowercase)": {"50tib", uint64(50 * math.Pow(2, 40)), nil},
+		"parse pebibyte (lowercase)": {"60pib", uint64(60 * math.Pow(2, 50)), nil},
+
+		"parse byte (with space)":     {"10 B", uint64(10 * math.Pow(2, 0)), nil},
+		"parse kibibyte (with space)": {"20 KIB", uint64(20 * math.Pow(2, 10)), nil},
+		"parse mebibyte (with space)": {"30 MIB", uint64(30 * math.Pow(2, 20)), nil},
+		"parse gibibyte (with space)": {"40 GIB", uint64(40 * math.Pow(2, 30)), nil},
+		"parse tebibyte (with space)": {"50 TIB", uint64(50 * math.Pow(2, 40)), nil},
+		"parse pebibyte (with space)": {"60 PIB", uint64(60 * math.Pow(2, 50)), nil},
+
+		"parse byte (with space, lowercase)":     {"10 b", uint64(10 * math.Pow(2, 0)), nil},
+		"parse kibibyte (with space, lowercase)": {"20 kib", uint64(20 * math.Pow(2, 10)), nil},
+		"parse mebibyte (with space, lowercase)": {"30 mib", uint64(30 * math.Pow(2, 20)), nil},
+		"parse gibibyte (with space, lowercase)": {"40 gib", uint64(40 * math.Pow(2, 30)), nil},
+		"parse tebibyte (with space, lowercase)": {"50 tib", uint64(50 * math.Pow(2, 40)), nil},
+		"parse pebibyte (with space, lowercase)": {"60 pib", uint64(60 * math.Pow(2, 50)), nil},
+
+		"parse kilobyte": {"20KB", uint64(20 * math.Pow(10, 3)), nil},
+		"parse megabyte": {"30MB", uint64(30 * math.Pow(10, 6)), nil},
+		"parse gigabyte": {"40GB", uint64(40 * math.Pow(10, 9)), nil},
+		"parse terabyte": {"50TB", uint64(50 * math.Pow(10, 12)), nil},
+		"parse petabyte": {"60PB", uint64(60 * math.Pow(10, 15)), nil},
+
+		"parse kilobyte (lowercase)": {"20kb", uint64(20 * math.Pow(10, 3)), nil},
+		"parse megabyte (lowercase)": {"30mb", uint64(30 * math.Pow(10, 6)), nil},
+		"parse gigabyte (lowercase)": {"40gb", uint64(40 * math.Pow(10, 9)), nil},
+		"parse terabyte (lowercase)": {"50tb", uint64(50 * math.Pow(10, 12)), nil},
+		"parse petabyte (lowercase)": {"60pb", uint64(60 * math.Pow(10, 15)), nil},
+
+		"parse kilobyte (with space)": {"20 KB", uint64(20 * math.Pow(10, 3)), nil},
+		"parse megabyte (with space)": {"30 MB", uint64(30 * math.Pow(10, 6)), nil},
+		"parse gigabyte (with space)": {"40 GB", uint64(40 * math.Pow(10, 9)), nil},
+		"parse terabyte (with space)": {"50 TB", uint64(50 * math.Pow(10, 12)), nil},
+		"parse petabyte (with space)": {"60 PB", uint64(60 * math.Pow(10, 15)), nil},
+
+		"parse kilobyte (with space, lowercase)": {"20 kb", uint64(20 * math.Pow(10, 3)), nil},
+		"parse megabyte (with space, lowercase)": {"30 mb", uint64(30 * math.Pow(10, 6)), nil},
+		"parse gigabyte (with space, lowercase)": {"40 gb", uint64(40 * math.Pow(10, 9)), nil},
+		"parse terabyte (with space, lowercase)": {"50 tb", uint64(50 * math.Pow(10, 12)), nil},
+		"parse petabyte (with space, lowercase)": {"60 pb", uint64(60 * math.Pow(10, 15)), nil},
+	} {
+		t.Run(desc, c.Assert)
+	}
+}
+
+func TestFormatBytes(t *testing.T) {
+	for desc, c := range map[string]*FormatBytesTestCase{
+		"format bytes":     {uint64(1 * math.Pow(10, 0)), "1 B"},
+		"format kilobytes": {uint64(1 * math.Pow(10, 3)), "1.0 KB"},
+		"format megabytes": {uint64(1 * math.Pow(10, 6)), "1.0 MB"},
+		"format gigabytes": {uint64(1 * math.Pow(10, 9)), "1.0 GB"},
+		"format petabytes": {uint64(1 * math.Pow(10, 12)), "1.0 TB"},
+		"format terabytes": {uint64(1 * math.Pow(10, 15)), "1.0 PB"},
+
+		"format kilobytes under": {uint64(1.49 * math.Pow(10, 3)), "1.5 KB"},
+		"format megabytes under": {uint64(1.49 * math.Pow(10, 6)), "1.5 MB"},
+		"format gigabytes under": {uint64(1.49 * math.Pow(10, 9)), "1.5 GB"},
+		"format petabytes under": {uint64(1.49 * math.Pow(10, 12)), "1.5 TB"},
+		"format terabytes under": {uint64(1.49 * math.Pow(10, 15)), "1.5 PB"},
+
+		"format kilobytes over": {uint64(1.51 * math.Pow(10, 3)), "1.5 KB"},
+		"format megabytes over": {uint64(1.51 * math.Pow(10, 6)), "1.5 MB"},
+		"format gigabytes over": {uint64(1.51 * math.Pow(10, 9)), "1.5 GB"},
+		"format petabytes over": {uint64(1.51 * math.Pow(10, 12)), "1.5 TB"},
+		"format terabytes over": {uint64(1.51 * math.Pow(10, 15)), "1.5 PB"},
+
+		"format kilobytes exact": {uint64(1.3 * math.Pow(10, 3)), "1.3 KB"},
+		"format megabytes exact": {uint64(1.3 * math.Pow(10, 6)), "1.3 MB"},
+		"format gigabytes exact": {uint64(1.3 * math.Pow(10, 9)), "1.3 GB"},
+		"format petabytes exact": {uint64(1.3 * math.Pow(10, 12)), "1.3 TB"},
+		"format terabytes exact": {uint64(1.3 * math.Pow(10, 15)), "1.3 PB"},
+	} {
+		t.Run(desc, c.Assert)
+	}
+}
diff --git a/tools/humanize/package.go b/tools/humanize/package.go
new file mode 100644
index 00000000..d7b480dc
--- /dev/null
+++ b/tools/humanize/package.go
@@ -0,0 +1,5 @@
+// package humanize is designed to parse and format "humanized" versions of
+// numbers with units.
+//
+// Based on: github.com/dustin/go-humanize.
+package humanize