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justinandClaude Opus 5 6d87fae60d feat(flr): windows paths, recovery-site gate, stable partition reads

Three fixes from measuring FLR against a Windows guest (ad1, VPG 'local')
instead of only the Linux one.

1. Gate FLR to locally replicated VPGs.

   FLR is performed at the VPG's RECOVERY site, because that is where the
   mount is created. A VPG replicating to a cloud ZCA has to be recovered
   through that ZCA's API, not the protected ZVM's. Supporting that
   properly means holding credentials for every ZVM/ZCA in an estate and
   routing the call, which is a real design decision, not something to
   smuggle in. Until then zerto_recover_file refuses a VPG whose
   protected site != recovery site and names the site that owns the
   operation, instead of failing later as a confusing path or mount error.

2. Windows paths are not symmetrical with Linux.

   Linux   /home/j/app.yaml  -> Volume2-Ext4%2fhome%2fj%2fapp.yaml
   Windows C:\Users\j\f.conf -> C%3a%2fUsers%2fj%2ff.conf

   On Windows the drive letter IS the partition name, so the guest path
   already carries it. The old code prepended unconditionally and built
   'C:/C:/Users/j', which could never match. resolve_flr_path now detects
   that the path already starts with the partition.

   It also returns the raw path exactly as browse reported it. Download
   accepts the raw and the decoded form, and returning raw avoids
   re-encoding by hand. Decoding is now unquote_plus, not unquote: browse
   form-encodes a space as '+' ("Program+Files"), so a basename compare
   against "Program Files" never matched. Matching tries exact first and
   only then case-insensitively, since Windows is case-insensitive and
   Linux is not.

3. Wait for partition enumeration to settle.

   A session reports mounted before the ZVM has finished identifying
   volumes, and browsing in that window returns a partial, MIS-LABELLED
   list. The same Windows VM enumerated as 'Volume4-Unknown' with no C:
   drive, then moments later as a browsable 'C%3a' holding the whole
   filesystem. Acting on the early list makes a restorable NTFS disk look
   permanently unrestorable. wait_partitions_stable polls until the list
   stops changing.

Verified against ZVM 10.x:

- CMH-AWS-4 (recovery aws-zca) refused, naming aws-zca
- C:\ad1.keytab recovered, 58 bytes
- C:\Program Files\internet explorer\sqmapi.dll recovered, 47512 bytes --
  drive letter, two spaces, nested dirs, the exact case that was broken
- Linux /home/justin/app-config.yaml still recovers, 158 bytes
- every session unmounted, unmount.ok true

Also drops a duplicate get_vpg that shadowed the existing one (F811).

pytest 32 passed (7 new).

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_016yVfC5nvZowoLFnEGWhLGn

2026-09-21 14:05:02 -04:00

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name, description

name	description
zerto-rewind	Before changing a VM, find its Zerto VPGs and insert a tagged checkpoint. Recover files from that tag with FLR after a human confirms. Use whenever an agent will mutate a guest that might be protected by Zerto.

Zerto rewind

Zerto already journals the VM. This skill makes the agent use that journal. Git does not have the guest file. Official ZVM MCP does not insert tagged checkpoints.

You talk to one MCP: zerto_rewind_mcp. Do not also require official ZVM MCP.

Loop (mandatory)

Before every guest-mutating tool call:

Take the hostname / VM name / Zerto vmIdentifier from the tool args.
Call zerto_guard_before_mutate with change_id and action (or zerto_find_protection then zerto_create_tagged_checkpoint).
If ok is not true: stop. Do not mutate.
Then run the mutating call.

Reads skip the guard.

Unlisted MCP tools pass through. If you are about to change a protected VM with a tool that is not in the catalog, call zerto_add_mutating_tool (server, tool, vm_arg) and then guard.

find_protection outcomes

outcome	what you do
none	Unprotected or unknown. Refuse the change. Say Zerto cannot rewind this.
ambiguous	Two or more VMs matched. Ask for a `vmIdentifier`. Do not guess.
ok, no taggable VPG	Syncing or not Protecting. Refuse. A resync deletes checkpoints.
ok, taggable VPGs	Tag every protecting VPG with the same tag. Wait until listed (the tool blocks).

A VM can be in up to three VPGs (local backup + remote DR is common). Tag all of them.

Recover

Human must confirm. Pass confirmed=true only after they say yes.

Bad config / dropped file: zerto_recover_file from that tag. Pass the guest path (/home/j/app.yaml or C:\Users\j\app.conf); the server maps it into the FLR namespace. Locally replicated VPGs only -- FLR happens at the recovery site, so a cloud-replicated VPG must be recovered from that ZCA. The tool refuses and names the site.
Inspect a whole VM: zerto_offsite_clone or zerto_start_failover_test.
Never Failover Live. Never Move. Those are DR, not rewind.

zerto_recover_file unmounts its own FLR session and reports the result in unmount. If unmount.ok is false, or a previous recovery died mid-flight, the mount is still up: FLR cannot run during clone, test, live failover or EJC, so a stuck session blocks the next recovery. Find it with zerto_list_flr_sessions and clear it with zerto_end_flr_session.

Facts that bite

A tagged checkpoint is crash-consistent, not app-quiesced.
Tagged checkpoints are not supported when the protected site is Azure or AWS. Talk to the vSphere protected ZVM.
10.9 FLR Operator RBAC fails; Administrator is the documented workaround.
FLR cannot run during clone, test, live failover, or EJC.
Linux FLR: files >1.5GB are a bad idea; some characters in names are refused.

Tag

The checkpoint name is the only field the Zerto API takes, so it carries the whole story:

ai:<agent> | <action> | vm=<vm> | change=<change-id> | <utc>
ai:claude | edit /etc/nginx/nginx.conf | vm=web01 | change=chg-412 | 20260921T150405Z

Always pass action: a plain description of the change you are about to make. An operator scrolling the journal in the Zerto UI should be able to tell which agent inserted the checkpoint and why, without reading your transcript.

Same string on every VPG for that call.

3.4 KiB Raw Blame History