Bug 1403169

Summary:	Snapshot : Snapshot restores fails, when nfs ganesha is disable and shared storage is down
Product:	[Red Hat Storage] Red Hat Gluster Storage	Reporter:	Anil Shah <ashah>
Component:	snapshot	Assignee:	Bug Updates Notification Mailing List <rhs-bugs>
Status:	CLOSED DEFERRED	QA Contact:	Rahul Hinduja <rhinduja>
Severity:	medium	Docs Contact:
Priority:	low
Version:	rhgs-3.2	CC:	amukherj, atumball, rcyriac, rhinduja, rhs-bugs, storage-qa-internal
Target Milestone:	---	Keywords:	Regression, ZStream
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Known Issue
Doc Text:	If nfs-ganesha was enabled while taking a snapshot, and during the restore of that snapshot it is disabled or shared storage is down, then the snapshot restore will fail.	Story Points:	---
Clone Of:
Clones:	1403188 (view as bug list)		Environment:
Last Closed:	2018-10-11 10:02:28 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1351530, 1403188

Description Anil Shah 2016-12-09 10:45:35 UTC

Description of problem:

Snapshot restores fails, when nfs ganesha was enabled while taking snapshot, and is disabled during snapshot restore and shared storage is down.

Version-Release number of selected component (if applicable):

glusterfs-3.8.4-7.el7rhgs.x86_64

How reproducible:

100%

Steps to Reproduce:
1. Create 2*2 distribute replicate volume
2. Enable cluster.enable-shared-storage 
3. enable nfs ganesha
4. create snapshot 
5. disable nfs ganesha
6. bring gluster-shared-storage volume
7. Restore snapshot 

Actual results:

Snapshot restore will fail


Expected results:

Snapshot restore should not fail

Additional info:
=============================================================

[2016-12-09 09:40:36.760986] E [MSGID: 106029] [glusterd-snapshot-utils.c:3412:glusterd_copy_file] 0-management: Unble to open a file /var/run/gluster/shared_storage/nfs-ganesha/exports/export.test-volume.conf
[2016-12-09 09:40:36.761015] E [MSGID: 106021] [glusterd-snapshot-utils.c:3957:glusterd_restore_nfs_ganesha_file] 0-management: Failed to copy /var/lib/glusterd/snaps/snap1/export.snap1.conf in /var/run/gluster/shared_storage/nfs-ganesha/exports/export.test-volume.conf [Cannot allocate memory]
[2016-12-09 09:40:36.761032] W [MSGID: 106043] [glusterd-snapshot.c:9946:gd_restore_snap_volume] 0-management: Failed to restore nfs-ganesha export file for snap snap1
[2016-12-09 09:40:36.761051] E [MSGID: 106043] [glusterd-snapshot.c:885:glusterd_snapshot_restore] 0-management: Failed to restore snap for snap1
[2016-12-09 09:40:36.761069] W [MSGID: 106043] [glusterd-snapshot.c:8433:glusterd_snapshot] 0-management: Failed to restore snapshot

Comment 2 Avra Sengupta 2016-12-09 11:17:23 UTC

RCA: Essentially a snapshot of a volume, which was taken when the volume had nfs.ganesha option enabled, has a export.conf file for it. This file will be restored to the Ganesha Export Directory, which has been moved to the shared storage. Currently we fail the snapshot restore in a scenario, where the snapshot has the said conf file, but the shared storage is not available. This behaviour is expected. However there is no option for the user to proceed with the snapshot at this point in time.

We will introduce  a force option for snapshot restore, which will enable the user to restore this particular snapshot in the above explained scenario, thereby abandoning the export.conf. The reason for introducing the force option is to make the user explicitly ask for the saved export.conf to be abandoned in such a scenario.

Since this fix involves introducing CLI change, we propose this to be deferred from 3.2.0

Comment 11 Amar Tumballi 2018-10-11 10:02:28 UTC

This issue is not considered for releases in last 2 years, RCA available. We are not focusing on fixing the issue in any immediate timeline.

Do raise priority on this, if required in any immediate releases!