Runaway VPG journal growth: applying a journal limit is slow to reclaim space, recreating the VPG is faster

Runaway VPG journal growth: applying a journal limit is slow to reclaim space, recreating the VPG is faster

Machine-distilled from a resolved support ticket on 2026-09-28. Source ref: 216b03448d8f. Verify before relying on it.

Applies to: Zerto Virtual Replication (vSphere), VPGs with journal history size set to unlimited or a very high limit, including cloud or DRaaS target sites managed by a provider

Symptom: A VPG's journal grows unusually large and keeps growing, sometimes reaching many terabytes. The same spike may appear on other replication paths protecting the same VM.

Cause: Abnormally high write or change activity inside the protected VM (for example a runaway process or unexpected disk churn) produces a large volume of changes. With no effective journal size limit, the journal absorbs all of these changes and grows without bound.

Resolution: 1. Ask the VM owner to check the protected VM for abnormal activity causing excessive disk changes, and resolve it (restarting the VM may stop the runaway activity). 2. If the cause cannot be found quickly, configure a journal size hard limit or threshold on the VPG to stop further growth, and tell the customer this will shorten the achievable journal history (retention). 3. Be aware that once a journal has already grown very large, applying a limit does not reclaim the space immediately: the journal can take days (up to around a week for multi terabyte journals) to shrink back within the limit. 4. If faster reclamation is needed and losing existing checkpoints is acceptable (for example on test or non critical VMs), delete the VPG to release the journal storage, then recreate it and let the initial sync complete. 5. To prevent recurrence, set a sensible default journal size limit rather than unlimited on similar VPGs. Where the target site is provider managed and the customer portal does not allow changing an unlimited journal setting, the provider must make the change on the customer's behalf.