diff --git a/fs-repo-11-to-12/go.mod b/fs-repo-11-to-12/go.mod
index 6a666f19..0d2769d8 100644
--- a/fs-repo-11-to-12/go.mod
+++ b/fs-repo-11-to-12/go.mod
@@ -7,7 +7,7 @@ require (
 	github.com/ipfs/fs-repo-migrations/tools v0.0.0-20211209222258-754a2dcb82ea
 	github.com/ipfs/go-cid v0.0.7
 	github.com/ipfs/go-datastore v0.4.5
-	github.com/ipfs/go-ds-badger v0.2.7-0.20211210151007-a2805355dcf5 // indirect
+	github.com/ipfs/go-ds-badger v0.2.7-0.20220117180822-159330558612 // indirect
 	github.com/ipfs/go-filestore v1.0.0
 	github.com/ipfs/go-ipfs v0.8.0
 	github.com/ipfs/go-ipfs-ds-help v1.0.0
diff --git a/fs-repo-11-to-12/go.sum b/fs-repo-11-to-12/go.sum
index a71c85a3..d68c6327 100644
--- a/fs-repo-11-to-12/go.sum
+++ b/fs-repo-11-to-12/go.sum
@@ -295,8 +295,8 @@ github.com/ipfs/go-ds-badger v0.0.7/go.mod h1:qt0/fWzZDoPW6jpQeqUjR5kBfhDNB65jd9
 github.com/ipfs/go-ds-badger v0.2.1/go.mod h1:Tx7l3aTph3FMFrRS838dcSJh+jjA7cX9DrGVwx/NOwE=
 github.com/ipfs/go-ds-badger v0.2.3/go.mod h1:pEYw0rgg3FIrywKKnL+Snr+w/LjJZVMTBRn4FS6UHUk=
 github.com/ipfs/go-ds-badger v0.2.6/go.mod h1:02rnztVKA4aZwDuaRPTf8mpqcKmXP7mLl6JPxd14JHA=
-github.com/ipfs/go-ds-badger v0.2.7-0.20211210151007-a2805355dcf5 h1:ovdpQk2ZVK6eQLzMCZy1z2tJae7yvE8xaPUw4Pr1RqI=
-github.com/ipfs/go-ds-badger v0.2.7-0.20211210151007-a2805355dcf5/go.mod h1:02rnztVKA4aZwDuaRPTf8mpqcKmXP7mLl6JPxd14JHA=
+github.com/ipfs/go-ds-badger v0.2.7-0.20220117180822-159330558612 h1:Uvp2/ZNlR3YmH04XJGv4YsPabhPzRPyeroLltVKBSr8=
+github.com/ipfs/go-ds-badger v0.2.7-0.20220117180822-159330558612/go.mod h1:02rnztVKA4aZwDuaRPTf8mpqcKmXP7mLl6JPxd14JHA=
 github.com/ipfs/go-ds-flatfs v0.4.5 h1:4QceuKEbH+HVZ2ZommstJMi3o3II+dWS3IhLaD7IGHs=
 github.com/ipfs/go-ds-flatfs v0.4.5/go.mod h1:e4TesLyZoA8k1gV/yCuBTnt2PJtypn4XUlB5n8KQMZY=
 github.com/ipfs/go-ds-leveldb v0.0.1/go.mod h1:feO8V3kubwsEF22n0YRQCffeb79OOYIykR4L04tMOYc=
diff --git a/fs-repo-11-to-12/migration/swapper.go b/fs-repo-11-to-12/migration/swapper.go
index df029ec9..aa6e6909 100644
--- a/fs-repo-11-to-12/migration/swapper.go
+++ b/fs-repo-11-to-12/migration/swapper.go
@@ -2,6 +2,8 @@ package mg11
 
 import (
 	"errors"
+	"os"
+	"strconv"
 	"sync"
 	"sync/atomic"
 
@@ -19,6 +21,32 @@ var SyncSize uint64 = 20 * 1024 * 1024 // 20MiB
 // migration.
 var NWorkers int = 4
 
+func init() {
+	workerEnvVar := "IPFS_FS_MIGRATION_11_TO_12_NWORKERS"
+	syncSizeEnvVar := "IPFS_FS_MIGRATION_11_TO_12_SYNC_SIZE_BYTES"
+	if nworkersStr, nworkerInEnv := os.LookupEnv(workerEnvVar); nworkerInEnv {
+		nworkers, err := strconv.Atoi(nworkersStr)
+		if err != nil {
+			panic(err)
+		}
+		if nworkers < 1 {
+			panic("number of workers must be at least 1")
+		}
+		NWorkers = nworkers
+	}
+
+	if syncSizeStr, syncSizeInEnv := os.LookupEnv(syncSizeEnvVar); syncSizeInEnv {
+		syncSize, err := strconv.ParseUint(syncSizeStr, 10, 64)
+		if err != nil {
+			panic(err)
+		}
+		if syncSize < 1 {
+			panic("sync size bytes must be at least 1")
+		}
+		SyncSize = syncSize
+	}
+}
+
 // Swap holds the datastore keys for the original CID and for the
 // destination Multihash.
 type Swap struct {
@@ -114,9 +142,11 @@ func (cswap *CidSwapper) swapWorker(dryRun bool, resultsCh <-chan query.Result)
 		oldKey := ds.NewKey(res.Key)
 		c, err := dsKeyToCid(ds.NewKey(oldKey.BaseNamespace())) // remove prefix
 		if err != nil {
-			// complain if we find anything that is not a CID but
+			// complain if we find anything that is not a CID or multihash but
 			// leave it as it is.
-			log.Log("could not parse %s as a Cid", oldKey)
+			if _, err := dshelp.DsKeyToMultihash(ds.NewKey(oldKey.BaseNamespace())); err != nil {
+				log.Log("could not parse %s as a Cid or Multihash", oldKey)
+			}
 			continue
 		}
 		if c.Version() == 0 { // CidV0 are multihashes, leave them.
diff --git a/fs-repo-11-to-12/vendor/github.com/ipfs/go-ds-badger/datastore.go b/fs-repo-11-to-12/vendor/github.com/ipfs/go-ds-badger/datastore.go
index 34780b4f..6d68dc16 100644
--- a/fs-repo-11-to-12/vendor/github.com/ipfs/go-ds-badger/datastore.go
+++ b/fs-repo-11-to-12/vendor/github.com/ipfs/go-ds-badger/datastore.go
@@ -87,7 +87,7 @@ var DefaultOptions Options
 
 func init() {
 	DefaultOptions = Options{
-		GcDiscardRatio: 0.2,
+		GcDiscardRatio: 0.5,
 		GcInterval:     2 * time.Minute,
 		GcSleep:        10 * time.Second,
 		Options:        badger.LSMOnlyOptions(""),
diff --git a/fs-repo-11-to-12/vendor/modules.txt b/fs-repo-11-to-12/vendor/modules.txt
index d4b3b274..157a1c19 100644
--- a/fs-repo-11-to-12/vendor/modules.txt
+++ b/fs-repo-11-to-12/vendor/modules.txt
@@ -123,7 +123,7 @@ github.com/ipfs/go-datastore/mount
 github.com/ipfs/go-datastore/namespace
 github.com/ipfs/go-datastore/query
 github.com/ipfs/go-datastore/sync
-# github.com/ipfs/go-ds-badger v0.2.7-0.20211210151007-a2805355dcf5
+# github.com/ipfs/go-ds-badger v0.2.7-0.20220117180822-159330558612
 ## explicit
 github.com/ipfs/go-ds-badger
 # github.com/ipfs/go-ds-flatfs v0.4.5
diff --git a/sharness/t0030-simple-migration.sh b/sharness/t0030-simple-migration.sh
index 9b368210..35127200 100755
--- a/sharness/t0030-simple-migration.sh
+++ b/sharness/t0030-simple-migration.sh
@@ -4,6 +4,8 @@ test_description="Simple fs-repo-migrations tests"
 
 . lib/test-lib.sh
 
+latestRepoVersion="12"
+
 test_expect_success "fs-repo-migrations binary is here" '
 	test -f "$LOCAL_FS_REPO_MIG"
 '
@@ -13,7 +15,7 @@ test_expect_success "'fs-repo-migrations -v' works" '
 '
 
 test_expect_success "'fs-repo-migrations -v' output looks good" '
-	echo "11" >expected &&
+	echo "$latestRepoVersion" >expected &&
 	test_cmp expected actual
 '
 
@@ -30,7 +32,7 @@ test_expect_success "'fs-repo-migrations -v' works" '
 '
 
 test_expect_success "'fs-repo-migrations -v' output looks good" '
-	echo "11" >expected &&
+	echo "$latestRepoVersion" >expected &&
 	test_cmp expected actual
 '