ivampiresp/longhorn
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

doc: Update doc for the remount feature

Browse Source 
Longhorn #950

Signed-off-by: Shuo Wu <shuo@rancher.com>
This commit is contained in:
Shuo Wu 2020-01-03 17:04:26 -08:00 committed by Sheng Yang
parent 2c10cb58ca
commit ede9a5f710
1 changed files with 11 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
docs/recover-volume.md
View File

@ -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 <filesystem 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/<volume name>`
## 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