Bug 1246223

Summary: EC pool uses only min_size, not the isRecoverablePredicate
Product: [Red Hat Storage] Red Hat Ceph Storage Reporter: Samuel Just <sjust>
Component: RADOSAssignee: Samuel Just <sjust>
Status: CLOSED ERRATA QA Contact: ceph-qe-bugs <ceph-qe-bugs>
Severity: low Docs Contact:
Priority: low    
Version: 1.3.0CC: ceph-eng-bugs, dzafman, flucifre, hnallurv, kchai, kdreyer, shmohan
Target Milestone: rc   
Target Release: 1.3.2   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: RHEL: ceph-0.94.5-2.el7cp Ubuntu: ceph_0.94.5-2redhat1 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2016-02-29 14:42:36 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:

Description Samuel Just 2015-07-23 17:57:26 UTC 
Description of problem:

EC pools do not use the IsRecoverablePredicate to determine whether a particular interval could have gone active.  For example, in a 4+2 ec pool with min_size=2 (which would be a dumb configuration, but possible), an interval with 3 osds would be marked as maybe_rw even though the primary OSD could not have gone active.

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


How reproducible:

Easy artificially, less so in the wild.  Not serious since you can work around by marking the missing osds as lost without losing any data.

Steps to Reproduce:
1. Create 6 osd 4+2 ec pool with min_size = 1
2. Kill 5 osds and mark down
3. Wait 1 minute
4. Kill the 6th.
5. Revive the first 5

Actual results:

PG goes to down state.

Expected results:

PG goes active+degraded since it could not have gone active in that state.

Additional info:
Comment 2 Samuel Just 2015-07-23 17:57:52 UTC 
Merged to master, pending backports.
Comment 3 Samuel Just 2015-07-23 17:58:52 UTC 
This does *not* need to be added for 1.3.1.
Comment 4 Ken Dreyer (Red Hat) 2015-12-11 21:39:27 UTC 
Shipped in v0.94.4 upstream - will be in RHCS 1.3.2
Comment 6 shylesh 2016-02-02 18:51:58 UTC 
verified on 
ceph-0.94.5-4.el7cp.x86_64

Now as part of CLI there is a check for ecpools which makes sure that min_size for an ecpool is never less than k and never greater than k+m value.

for ex: I created an ecpool with 4+2 configuration. Now if i try to change the min_size of the pool 

sudo ceph osd pool set ecpool min_size 1
Error EINVAL: pool min_size must be between 4 and 6


hence marking this as verified
Comment 8 errata-xmlrpc 2016-02-29 14:42:36 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/RHBA-2016:0313