diff --git a/docs/recover-volume.md b/docs/recover-volume.md index ad86aaa..10a7f82 100644 --- a/docs/recover-volume.md +++ b/docs/recover-volume.md @@ -2,7 +2,16 @@ ## Overview 1. Now Longhorn can automatically reattach then remount volumes if unexpected detachment happens. e.g., [Kubernetes upgrade](https://github.com/longhorn/longhorn/issues/703), [Docker reboot](https://github.com/longhorn/longhorn/issues/686). -2. After reattachment and remount complete, users may need to **manually restart the related workload containers** for the volume restoration **if the following recommended setup is not applied**. +2. After **reattachment** and **remount** complete, users may need to **manually restart the related workload containers** for the volume restoration **if the following recommended setup is not applied**. + +#### Reattachment +Longhorn will reattach the volume if the volume engine deads unexpectedly. + +#### Remount +- Longhorn will detect and remount filesystem for the volume after the reattachment. +- But **the auto remount does not work for `xfs` filesystem**. + - Since mounting one more layers with `xfs` filesystem is not allowed and will trigger the error `XFS (sdb): Filesystem has duplicate UUID - can't mount`. + - Users need to manually unmount then mount the `xfs` filesystem on the host. The device path on host for the attached volume is `/dev/longhorn/` ## Recommended setup when using Longhorn volumes In order to recover unexpectedly detached volumes automatically, users can set `restartPolicy` to `Always` then add `livenessProbe` for the workloads using Longhorn volumes. @@ -55,7 +64,7 @@ spec: ## Manually restart workload containers ## This solution is applied only if: -1. The Longhorn volume is reattached automatically. +1. The Longhorn volume is reattached and remounted automatically. 2. The above setup is not included when the related workload is launched. ### Steps