--- a/ansible/roles/docker-hg-ssh/files/create-repo
+++ b/ansible/roles/docker-hg-ssh/files/create-repo
@@ -9,27 +9,29 @@ REPO=$1
 GROUP=$2
 
 for arg in "$@"
 do
     case $arg in
         --non-publishing)
         NONPUBLISHING=1
         ;;
-        --generaldelta)
-        GENERALDELTA=1
+        --no-generaldelta)
+        NO_GENERALDELTA=1
         ;;
         *)
         ;;
     esac
 done
 
 INITFLAGS=
-if [ -n "${GENERALDELTA}" ]; then
-  INITFLAGS="--config format.generaldelta=true"
+if [ -n "${NO_GENERALDELTA}" ]; then
+  INITFLAGS="--config format.usegeneraldelta=false"
+else
+  INITFLAGS="--config format.usegeneraldelta=true"
 fi
 
 /var/hg/venv_tools/bin/hg init /repo/hg/mozilla/${REPO} ${INITFLAGS}
 chown -R hg:${GROUP} /repo/hg/mozilla/${REPO}
 find /repo/hg/mozilla/${REPO} | xargs chmod g+w
 find /repo/hg/mozilla/${REPO} -type d | xargs chmod g+s
 
 if [ -n "${NONPUBLISHING}" ]; then

--- a/hgserver/tests/test-clonebundles.t
+++ b/hgserver/tests/test-clonebundles.t
@@ -1,17 +1,17 @@
 #require hgmodocker
 
   $ . $TESTDIR/hgserver/tests/helpers.sh
   $ hgmoenv
   $ standarduser
 
 Create and seed repository
 
-  $ hgmo create-repo mozilla-central scm_level_1
+  $ hgmo create-repo mozilla-central scm_level_1 --no-generaldelta
   (recorded repository creation in replication log)
 
   $ hg clone ssh://${SSH_SERVER}:${SSH_PORT}/mozilla-central > /dev/null
   $ cd mozilla-central
   $ touch foo
   $ hg -q commit -A -m initial
   $ hg push > /dev/null
   $ cd ..
@@ -190,17 +190,17 @@ Fetching with an AWS IP from "other" reg
   https://hg.cdn.mozilla.net/mozilla-central/77538e1ce4bec5f7aac58a7ceca2da0e38e90a72.gzip.hg compression=gzip cdn=true requiresni=true
   https://s3-us-west-2.amazonaws.com/moz-hg-bundles-us-west-2/mozilla-central/77538e1ce4bec5f7aac58a7ceca2da0e38e90a72.gzip.hg ec2region=us-west-2 compression=gzip
   https://s3-us-west-1.amazonaws.com/moz-hg-bundles-us-west-1/mozilla-central/77538e1ce4bec5f7aac58a7ceca2da0e38e90a72.gzip.hg ec2region=us-west-1 compression=gzip
   https://s3-external-1.amazonaws.com/moz-hg-bundles-us-east-1/mozilla-central/77538e1ce4bec5f7aac58a7ceca2da0e38e90a72.gzip.hg ec2region=us-east-1 compression=gzip
   https://s3-eu-central-1.amazonaws.com/moz-hg-bundles-eu-central-1/mozilla-central/77538e1ce4bec5f7aac58a7ceca2da0e38e90a72.gzip.hg ec2region=eu-central-1 compression=gzip
 
 The copyfrom=x field copies bundles from another repo
 
-  $ hgmo create-repo try scm_level_1
+  $ hgmo create-repo try scm_level_1 --no-generaldelta
   (recorded repository creation in replication log)
   $ hg -q clone ssh://${SSH_SERVER}:${SSH_PORT}/try
   $ cd try
   $ touch foo
   $ hg -q commit -A -m initial
   $ hg push > /dev/null
   $ cd ..
 
@@ -312,17 +312,17 @@ zstd-max bundles created when requested
   https://hg.cdn.mozilla.net/mozilla-central/934273ae8830f7bf6f12950ba87e02185a177467.packed1.hg BUNDLESPEC=none-packed1;requirements%3Drevlogv1 REQUIRESNI=true cdn=true
   https://s3-us-west-2.amazonaws.com/moz-hg-bundles-us-west-2/mozilla-central/934273ae8830f7bf6f12950ba87e02185a177467.packed1.hg BUNDLESPEC=none-packed1;requirements%3Drevlogv1 ec2region=us-west-2
   https://s3-us-west-1.amazonaws.com/moz-hg-bundles-us-west-1/mozilla-central/934273ae8830f7bf6f12950ba87e02185a177467.packed1.hg BUNDLESPEC=none-packed1;requirements%3Drevlogv1 ec2region=us-west-1
   https://s3-external-1.amazonaws.com/moz-hg-bundles-us-east-1/mozilla-central/934273ae8830f7bf6f12950ba87e02185a177467.packed1.hg BUNDLESPEC=none-packed1;requirements%3Drevlogv1 ec2region=us-east-1
   https://s3-eu-central-1.amazonaws.com/moz-hg-bundles-eu-central-1/mozilla-central/934273ae8830f7bf6f12950ba87e02185a177467.packed1.hg BUNDLESPEC=none-packed1;requirements%3Drevlogv1 ec2region=eu-central-1
 
 Generaldelta repos should create zstd-v2, gzip-v2, and streamclone bundles only
 
-  $ hgmo create-repo generaldelta scm_level_1 --generaldelta
+  $ hgmo create-repo generaldelta scm_level_1
   (recorded repository creation in replication log)
   $ hg -q clone ssh://${SSH_SERVER}:${SSH_PORT}/generaldelta
   $ cd generaldelta
   $ touch foo
   $ hg -q commit -A -m initial
   $ hg push > /dev/null
   $ cd ..
 

--- a/hgserver/tests/test-obsolescence.t
+++ b/hgserver/tests/test-obsolescence.t
@@ -302,17 +302,17 @@ and we're not in the allowed user list
 
   $ hgmo exec hgssh /var/hg/venv_pash/bin/hg -R /repo/hg/mozilla/integration/autoland debugobsolete
 
 hgweb advertise marker exchange
 
   $ http --no-headers "${HGWEB_0_URL}integration/autoland?cmd=capabilities"
   200
   
-  lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch stream bundle2=HG20%0Achangegroup%3D01%2C02%0Adigests%3Dmd5%2Csha1%2Csha512%0Aerror%3Dabort%2Cunsupportedcontent%2Cpushraced%2Cpushkey%0Ahgtagsfnodes%0Alistkeys%0Aobsmarkers%3DV0%2CV1%0Apushkey%0Aremote-changegroup%3Dhttp%2Chttps unbundle=HG10GZ,HG10BZ,HG10UN httpheader=6144 pushlog
+  lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 bundle2=HG20%0Achangegroup%3D01%2C02%0Adigests%3Dmd5%2Csha1%2Csha512%0Aerror%3Dabort%2Cunsupportedcontent%2Cpushraced%2Cpushkey%0Ahgtagsfnodes%0Alistkeys%0Aobsmarkers%3DV0%2CV1%0Apushkey%0Aremote-changegroup%3Dhttp%2Chttps unbundle=HG10GZ,HG10BZ,HG10UN httpheader=6144 pushlog
 
 Allow this user to send obsolescence markers (since the per-repo hgrc will get replicated
 and take precedence on the mirror, we need to add the allowed user from the replication
 processes on both server and mirror)
 
   $ hgmo exec hgssh /set-hgrc-option integration/autoland obshacks obsolescenceexchangeusers "user@example.com,vcs-sync@mozilla.com,hg"
   $ hgmo exec hgssh /var/hg/venv_pash/bin/hg -R /repo/hg/mozilla/integration/autoland replicatehgrc
   recorded hgrc in replication log
@@ -347,13 +347,13 @@ And they should get replicated to mirror
   5fb779ae39de4af3229a53c35d46117e98fb5f83 d57129f00b2f329fc2cf3371a0c28796bcfbde1c 0 (*) {'user': 'Test User <someone@example.com>'} (glob)
   d57129f00b2f329fc2cf3371a0c28796bcfbde1c 9e2d548e5f1f94b9172cfeb77b53f5943722b594 0 (*) {'user': 'Test User <someone@example.com>'} (glob)
 
 hgweb should still advertise marker exchange
 
   $ http --no-headers "${HGWEB_0_URL}integration/autoland?cmd=capabilities"
   200
   
-  lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch stream bundle2=HG20%0Achangegroup%3D01%2C02%0Adigests%3Dmd5%2Csha1%2Csha512%0Aerror%3Dabort%2Cunsupportedcontent%2Cpushraced%2Cpushkey%0Ahgtagsfnodes%0Alistkeys%0Aobsmarkers%3DV0%2CV1%0Apushkey%0Aremote-changegroup%3Dhttp%2Chttps unbundle=HG10GZ,HG10BZ,HG10UN httpheader=6144 pushlog
+  lookup changegroupsubset branchmap pushkey known getbundle unbundlehash batch streamreqs=generaldelta,revlogv1 bundle2=HG20%0Achangegroup%3D01%2C02%0Adigests%3Dmd5%2Csha1%2Csha512%0Aerror%3Dabort%2Cunsupportedcontent%2Cpushraced%2Cpushkey%0Ahgtagsfnodes%0Alistkeys%0Aobsmarkers%3DV0%2CV1%0Apushkey%0Aremote-changegroup%3Dhttp%2Chttps unbundle=HG10GZ,HG10BZ,HG10UN httpheader=6144 pushlog
 
   $ cd ..
 
   $ hgmo clean

--- a/pylib/vcsreplicator/tests/test-changegroup-replicate.t
+++ b/pylib/vcsreplicator/tests/test-changegroup-replicate.t
@@ -27,17 +27,17 @@ Pushing the initial commit will result i
   remote: recorded push in pushlog
   remote: 
   remote: View your change here:
   remote:   https://hg.mozilla.org/mozilla-central/rev/77538e1ce4bec5f7aac58a7ceca2da0e38e90a72
   remote: recorded changegroup in replication log in \d\.\d+s (re)
 
   $ consumer --dump --partition 2
   - _created: \d+\.\d+ (re)
-    generaldelta: false
+    generaldelta: true
     name: hg-repo-init-2
     path: '{moz}/mozilla-central'
   - _created: \d+\.\d+ (re)
     name: heartbeat-1
   - _created: \d+\.\d+ (re)
     name: heartbeat-1
   - _created: \d+\.\d+ (re)
     heads:

--- a/pylib/vcsreplicator/tests/test-hgrc-replicate.t
+++ b/pylib/vcsreplicator/tests/test-hgrc-replicate.t
@@ -9,17 +9,17 @@
 hgrc file content is sent in a message
 
   $ hgmo exec hgssh /set-hgrc-option mozilla-central hooks dummy value
   $ hgmo exec hgssh /var/hg/venv_pash/bin/hg -R /repo/hg/mozilla/mozilla-central replicatehgrc
   recorded hgrc in replication log
 
   $ consumer --dump --partition 2
   - _created: \d+\.\d+ (re)
-    generaldelta: false
+    generaldelta: true
     name: hg-repo-init-2
     path: '{moz}/mozilla-central'
   - _created: \d+\.\d+ (re)
     content: '[hooks]
   
       dummy = value
   
   
@@ -37,17 +37,17 @@ hgrc should have been written on client
 Replicating hgrc without hgrc file will delete file
 
   $ hgmo exec hgssh rm /repo/hg/mozilla/mozilla-central/.hg/hgrc
   $ hgmo exec hgssh /var/hg/venv_pash/bin/hg -R /repo/hg/mozilla/mozilla-central replicatehgrc
   recorded hgrc in replication log
 
   $ consumer --dump --partition 2
   - _created: \d+\.\d+ (re)
-    generaldelta: false
+    generaldelta: true
     name: hg-repo-init-2
     path: '{moz}/mozilla-central'
   - _created: \d+\.\d+ (re)
     content: '[hooks]
   
       dummy = value
   
   
@@ -68,17 +68,17 @@ Unicode in hgrc is preserved
 
   $ docker exec ${SSH_CID} /set-hgrc-option mozilla-central hooks dummy 'こんにちは'
 
   $ hgmo exec hgssh /var/hg/venv_pash/bin/hg -R /repo/hg/mozilla/mozilla-central replicatehgrc
   recorded hgrc in replication log
 
   $ consumer --dump --partition 2
   - _created: \d+\.\d+ (re)
-    generaldelta: false
+    generaldelta: true
     name: hg-repo-init-2
     path: '{moz}/mozilla-central'
   - _created: \d+\.\d+ (re)
     content: '[hooks]
   
       dummy = value
   
   

--- a/pylib/vcsreplicator/tests/test-init.t
+++ b/pylib/vcsreplicator/tests/test-init.t
@@ -2,17 +2,17 @@
 
   $ . $TESTDIR/pylib/vcsreplicator/tests/helpers.sh
   $ vcsrenv
 
 Creating a repository should record an event saying so
 
   $ hgmo exec hgweb0 ls /repo/hg/mozilla
 
-  $ hgmo create-repo mozilla-central scm_level_3
+  $ hgmo create-repo mozilla-central scm_level_3 --no-generaldelta
   (recorded repository creation in replication log)
 
   $ hgmo exec hgssh cat /repo/hg/mozilla/mozilla-central/.hg/requires
   dotencode
   fncache
   revlogv1
   store
 
@@ -57,17 +57,17 @@ Creating a repository should record an e
   $ hgmo exec hgweb0 cat /repo/hg/mozilla/mozilla-central/.hg/requires
   dotencode
   fncache
   revlogv1
   store
 
 generaldelta is preserved
 
-  $ hgmo create-repo mcgd scm_level_3 --generaldelta
+  $ hgmo create-repo mcgd scm_level_3
   (recorded repository creation in replication log)
 
   $ hgmo exec hgssh cat /repo/hg/mozilla/mcgd/.hg/requires
   dotencode
   fncache
   generaldelta
   revlogv1
   store

--- a/pylib/vcsreplicator/tests/test-pushaggregator.t
+++ b/pylib/vcsreplicator/tests/test-pushaggregator.t
@@ -18,17 +18,17 @@ The aggregate topic should contain a hea
   $ paconsumer --dump
   - _created: \d+\.\d+ (re)
     _original_created: \d+\.\d+ (re)
     _original_partition: 0
     name: heartbeat-1
   - _created: \d+\.\d+ (re)
     _original_created: \d+\.\d+ (re)
     _original_partition: 2
-    generaldelta: false
+    generaldelta: true
     name: hg-repo-init-2
     path: '{moz}/mozilla-central'
 
   $ hg -q clone ssh://${SSH_SERVER}:${SSH_PORT}/mozilla-central
   $ cd mozilla-central
 
   $ touch foo
   $ hg -q commit -A -m initial
@@ -167,29 +167,29 @@ Aggregation of messages from multiple pa
     name: heartbeat-1
   - _created: \d+\.\d+ (re)
     _original_created: \d+\.\d+ (re)
     _original_partition: 0
     name: heartbeat-1
   - _created: \d+\.\d+ (re)
     _original_created: \d+\.\d+ (re)
     _original_partition: 2
-    generaldelta: false
+    generaldelta: true
     name: hg-repo-init-2
     path: '{moz}/mc2'
   - _created: \d+\.\d+ (re)
     _original_created: \d+\.\d+ (re)
     _original_partition: 4
-    generaldelta: false
+    generaldelta: true
     name: hg-repo-init-2
     path: '{moz}/try'
   - _created: \d+\.\d+ (re)
     _original_created: \d+\.\d+ (re)
     _original_partition: 7
-    generaldelta: false
+    generaldelta: true
     name: hg-repo-init-2
     path: '{moz}/users/foo'
 
 --max-polls argument exits process after N intervals
 
   $ hgmo exec hgssh /var/hg/venv_tools/bin/vcsreplicator-aggregator --max-polls 1 /etc/mercurial/pushdataaggregator.ini
   vcsreplicator.aggregator hit max polls threshold; exiting
   vcsreplicator.aggregator executing loop exiting gracefully

--- a/pylib/vcsreplicator/tests/test-sync.t
+++ b/pylib/vcsreplicator/tests/test-sync.t
@@ -10,33 +10,34 @@
 
   $ hgmo exec hgssh /set-hgrc-option mozilla-central hooks foo bar
 
   $ hgmo exec hgssh /var/hg/venv_tools/bin/hg -R /repo/hg/mozilla/mozilla-central replicatesync
   wrote synchronization message into replication log
 
   $ consumer --dump --partition 2
   - _created: \d+\.\d+ (re)
-    generaldelta: false
+    generaldelta: true
     name: hg-repo-init-2
     path: '{moz}/mozilla-central'
   - _created: \d+\.\d+ (re)
     heads:
     - '0000000000000000000000000000000000000000'
     hgrc: '[hooks]
   
       foo = bar
   
   
       '
     name: hg-repo-sync-1
     path: '{moz}/mozilla-central'
     requirements:
     - dotencode
     - fncache
+    - generaldelta
     - revlogv1
     - store
 
   $ hgmo exec hgweb0 /var/hg/venv_replication/bin/vcsreplicator-consumer --wait-for-no-lag /etc/mercurial/vcsreplicator.ini
 
   $ hgmo exec hgweb0 cat /var/log/vcsreplicator/consumer.log
   No handlers could be found for logger "kafka.conn"
   No handlers could be found for logger "kafka.conn"

--- a/testing/vcttesting/hgmo.py
+++ b/testing/vcttesting/hgmo.py
@@ -488,28 +488,28 @@ class HgCluster(object):
             f_host_rsa_key = e.submit(self._d.get_file_content, master_id,
                                       '/etc/mercurial/ssh/ssh_host_rsa_key.pub')
 
         host_ed25519_key = ' '.join(f_host_ed25519_key.result().split()[0:2])
         host_rsa_key = ' '.join(f_host_rsa_key.result().split()[0:2])
 
         return f_private_key.result(), f_public_key.result(), host_ed25519_key, host_rsa_key
 
-    def create_repo(self, name, group='scm_level_1', generaldelta=False):
+    def create_repo(self, name, group='scm_level_1', no_generaldelta=False):
         """Create a repository on the cluster.
 
         ``path`` is the path fragment the repository would be accessed under
         at https://hg.mozilla.org. e.g. ``hgcustom/version-control-tools``.
 
         The repository will be owned by the specified ``group``.
         """
         cmd = ['/create-repo', name, group]
 
-        if generaldelta:
-            cmd.append('--generaldelta')
+        if no_generaldelta:
+            cmd.append('--no-generaldelta')
 
         return self._d.execute(self.master_id, cmd, stdout=True, stderr=True)
 
     def aggregate_code_coverage(self, destdir):
         master_map = {}
         for host, container in self.MASTER_FILE_MAP.items():
             master_map[container] = os.path.join(ROOT, host)
 

--- a/testing/vcttesting/hgmo_mach_commands.py
+++ b/testing/vcttesting/hgmo_mach_commands.py
@@ -133,20 +133,21 @@ class HgmoCommands(object):
         self.c.ldap.add_user_to_group(email, group)
 
     @Command('create-repo', category='hgmo',
              description='Create a repository in the cluster')
     @CommandArgument('name',
                      help='Name of repository to create')
     @CommandArgument('group', default='scm_level_1',
                      help='LDAP group that owns repo')
-    @CommandArgument('--generaldelta', action='store_true',
-                     help='Create repository with generaldelta storage')
-    def create_repo(self, name, group, generaldelta=True):
-        out = self.c.create_repo(name, group=group, generaldelta=generaldelta)
+    @CommandArgument('--no-generaldelta', action='store_true',
+                     help='Create repository without generaldelta storage')
+    def create_repo(self, name, group, no_generaldelta=False):
+        out = self.c.create_repo(name, group=group,
+                                 no_generaldelta=no_generaldelta)
         if out:
             sys.stdout.write(out)
 
     @Command('aggregate-code-coverage', category='hgmo',
              description='Aggregate code coverage results to a directory')
     @CommandArgument('destdir',
                      help='Directory where to save code coverage files')
     def aggregate_code_coverage(self, destdir):