[Openstack-operators] After power outage, nearly all vm volumes corrupted and unmountable

Gary Molenkamp molenkam at uwo.ca
Fri Jul 6 11:55:17 UTC 2018

Good morning all,

After losing all power to our DC last night due to a storm, nearly all 
of the volumes in our Pike cluster are unmountable.  Of the 30 VMs in 
use at the time, only one has been able to successfully mount and boot 
from its rootfs.   We are using Ceph as the backend storage to cinder 
and glance.  Any help or pointers to bring this back online would be 

  What most of the volumes are seeing is

[    2.622252] SGI XFS with ACLs, security attributes, no debug enabled
[    2.629285] XFS (sda1): Mounting V5 Filesystem
[    2.832223] sd 2:0:0:0: [sda] FAILED Result: hostbyte=DID_OK 
[    2.838412] sd 2:0:0:0: [sda] Sense Key : Aborted Command [current]
[    2.842383] sd 2:0:0:0: [sda] Add. Sense: I/O process terminated
[    2.846152] sd 2:0:0:0: [sda] CDB: Write(10) 2a 00 00 80 2c 19 00 04 
00 00
[    2.850146] blk_update_request: I/O error, dev sda, sector 8399897


[    2.590178] EXT4-fs (vda1): INFO: recovery required on readonly 
[    2.594319] EXT4-fs (vda1): write access will be enabled during recovery
[    2.957742] print_req_error: I/O error, dev vda, sector 227328
[    2.962468] Buffer I/O error on dev vda1, logical block 0, lost async 
page write
[    2.967933] Buffer I/O error on dev vda1, logical block 1, lost async 
page write
[    2.973076] print_req_error: I/O error, dev vda, sector 229384

As a test for one of the less critical vms, I deleted the vm and mounted 
the volume on the one VM I managed to start.  The results were not 

# dmesg |tail
[    5.136862] type=1305 audit(1530847244.811:4): audit_pid=496 old=0 
auid=4294967295 ses=4294967295 subj=system_u:system_r:auditd_t:s0 res=1
[    7.726331] nf_conntrack version 0.5.0 (65536 buckets, 262144 max)
[29374.967315] scsi 2:0:0:1: Direct-Access     QEMU     QEMU HARDDISK    
2.5+ PQ: 0 ANSI: 5
[29374.988104] sd 2:0:0:1: [sdb] 83886080 512-byte logical blocks: (42.9 
GB/40.0 GiB)
[29374.991126] sd 2:0:0:1: Attached scsi generic sg1 type 0
[29374.995302] sd 2:0:0:1: [sdb] Write Protect is off
[29374.997109] sd 2:0:0:1: [sdb] Mode Sense: 63 00 00 08
[29374.997186] sd 2:0:0:1: [sdb] Write cache: enabled, read cache: 
enabled, doesn't support DPO or FUA
[29375.005968]  sdb: sdb1
[29375.007746] sd 2:0:0:1: [sdb] Attached SCSI disk

# parted /dev/sdb
GNU Parted 3.1
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) p
Disk /dev/sdb: 42.9GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number  Start   End     Size    Type     File system  Flags
  1      1049kB  42.9GB  42.9GB  primary  xfs          boot

# mount -t xfs /dev/sdb temp
mount: wrong fs type, bad option, bad superblock on /dev/sdb,
        missing codepage or helper program, or other error

        In some cases useful info is found in syslog - try
        dmesg | tail or so.

# xfs_repair /dev/sdb
Phase 1 - find and verify superblock...
bad primary superblock - bad magic number !!!

attempting to find secondary superblock...

Which eventually fails.   The ceph cluster looks healthy, I can export 
the volumes from rbd.  I can find no other errors in ceph of openstack 
indicating a fault in either system.

     - Is this recoverable?

     - What happened to all of these volumes and can this be prevented 
from occurring again?  Note that any shutdown vm at the time of the 
outage appears to be fine.

Relevant versions:

     Base OS:  all Centos 7.5

     Ceph:  Luminous 12.2.5-0

     Openstack:  Latest Pike releases in centos-release-openstack-pike-1-1

         nova 16.1.4-1

         cinder  11.1.1-1

Gary Molenkamp			Computer Science/Science Technology Services
Systems Administrator		University of Western Ontario
molenkam at uwo.ca                 http://www.csd.uwo.ca
(519) 661-2111 x86882		(519) 661-3566

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