Bug 1255830

Summary:	FAILED assert(m_seed < old_pg_num) in librbd when increasing placement groups
Product:	[Red Hat Storage] Red Hat Ceph Storage	Reporter:	Jason Dillaman <jdillama>
Component:	RBD	Assignee:	Josh Durgin <jdurgin>
Status:	CLOSED ERRATA	QA Contact:	ceph-qe-bugs <ceph-qe-bugs>
Severity:	high	Docs Contact:
Priority:	high
Version:	1.3.0	CC:	bhubbard, ceph-eng-bugs, ceph-qe-bugs, flucifre, jdillama, jdurgin, kdreyer, tganguly, tmuthami, vumrao
Target Milestone:	rc
Target Release:	1.3.1
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	ceph-0.94.2-8.el7cp	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	1255827
Clones:	1258625 (view as bug list)		Environment:
Last Closed:	2015-11-23 20:22:15 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:

Comment 5 Tanay Ganguly 2015-10-28 10:33:21 UTC

Jason,

I tried the following and it worked fine, please let me know if there is any further validation required.

Below are the 2 use case by which i verified.

1st Use case:

1. Created rbd image, took snapshot and cloned it.
2. Mapped it to a VM and installed OS on top of it.
3. Started writing some IO using dd, then abruptly shutdown the VM.

Meanwhile i opened a watch instance on that image, while shutting down the VM.
rbd watch --pool Tanay-RBD testingClone_new1

While all this was happening, i incremented the pg_num and pgp_num in a loop (50 times )for that pool.

I didn't see any FAILED assert error message in watch/log.

Only thing i am seeing in watch is:

[root@cephqe3 ceph-config]# rbd watch --pool Tanay-RBD testingClone_new1
press enter to exit...
testingClone_new1 received notification: notify_id=3435973836800, cookie=48502592, notifier_id=1467375, bl.length=26
testingClone_new1 received notification: notify_id=3435973836801, cookie=48502592, notifier_id=1468015, bl.length=26
testingClone_new1 received notification: notify_id=3453153705986, cookie=48502592, notifier_id=1469010, bl.length=26


2nd Use case is:

1. Created rbd image, took snapshot and cloned it.
2. Exercised librbd api calls, image.write and image.read


Meanwhile i opened a watch instance on that image.
rbd watch --pool Tanay-RBD testingClone_new3

While all this was happening, i incremented the pg_num and pgp_num in a loop (50 times )for that pool 


Thanks.

Comment 6 Jason Dillaman 2015-10-28 14:10:35 UTC

Your first test showed that the watch was still established since you received messages.  For future reference, you can just use 'rados -p <pool> listwatchers <image  name>.rbd' (assuming RBD image format 1 for ease of header lookup) to verify that the image still has a valid watch after resizing the PG.

Comment 7 Tanay Ganguly 2015-10-28 14:36:52 UTC

Marking this Bug as Verified.

Comment 9 errata-xmlrpc 2015-11-23 20:22:15 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2015:2512

Comment 10 Siddharth Sharma 2015-11-23 21:53:23 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2015:2066