Bug#809447: mdadm: update=metadata with 4TB disks result in different sizes and superblock versions
Ralph Kaptur
reportbug at kaptur.de
Wed Dec 30 19:28:52 UTC 2015
Package: mdadm
Version: 3.3.2-5
Severity: normal
Dear Maintainer,
*** Reporter, please consider answering these questions, where appropriate ***
* What led up to the situation?
* What exactly did you do (or not do) that was effective (or
ineffective)?
* What was the outcome of this action?
* What outcome did you expect instead?
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-- Package-specific info:
IMPORTANT:
please do not forget to include all relevant system information with this
bug report. You could run
/usr/share/bug/mdadm/script 3>&1
as root and attach or include the output.
-- System Information:
Debian Release: 8.0
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 3.16.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)
Versions of packages mdadm depends on:
ii debconf [debconf-2.0] 1.5.56
ii initscripts 2.88dsf-59
ii libc6 2.19-18+deb8u1
ii lsb-base 4.1+Debian13+nmu1
ii udev 215+12+betsy
Versions of packages mdadm recommends:
pn default-mta | mail-transport-agent <none>
ii kmod 18-3
ii module-init-tools 18-3
mdadm suggests no packages.
-- debconf information:
mdadm/start_daemon: true
* mdadm/initrdstart: all
mdadm/initrdstart_msg_errconf:
mdadm/autocheck: true
mdadm/initrdstart_msg_errblock:
mdadm/initrdstart_msg_intro:
mdadm/initrdstart_msg_errmd:
mdadm/initrdstart_notinconf: false
mdadm/initrdstart_msg_errexist:
mdadm/mail_to: root
###################################################################
here we go:
this is a raid 1 (/dev/md3) with 2 8TB disks (/dev/sdb1 and /dev/sdc1) with original superblock 0.90
after
mdadm -A --update=metadata /dev/md3 /dev/sdb1 /dev/sdc1
the size has shrinked and the filesystem no longer working.
Starting with -e 0 and the raid can be used with 4TB, but no metadate update possible any more
ralix ralph # mdadm -Evvvvs
/dev/sdb1:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x0
Array UUID : 9d3b4c33:07aaf76e:6aefa58e:ac893c19
Name : 3
Creation Time : Sat May 9 22:58:19 2009
Raid Level : raid1
Raid Devices : 2
Avail Dev Size : 4294967294 (2048.00 GiB 2199.02 GB)
Array Size : 2147483647 (2048.00 GiB 2199.02 GB)
Super Offset : 15624998896 sectors
Unused Space : before=0 sectors, after=11330031602 sectors
State : clean
Device UUID : fe89c915:918a94a0:78eeecb7:78981a5d
Update Time : Wed Dec 30 18:28:22 2015
Checksum : 295dc1d - correct
Events : 0
Device Role : Active device 0
Array State : AA ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdc1:
Magic : a92b4efc
Version : 1.0
Feature Map : 0x0
Array UUID : 9d3b4c33:07aaf76e:6aefa58e:ac893c19
Name : 3
Creation Time : Sat May 9 22:58:19 2009
Raid Level : raid1
Raid Devices : 2
Avail Dev Size : 4294967294 (2048.00 GiB 2199.02 GB)
Array Size : 2147483647 (2048.00 GiB 2199.02 GB)
Super Offset : 15624998896 sectors
Unused Space : before=0 sectors, after=11330031602 sectors
State : clean
Device UUID : 34500844:ab3f3925:ca7aae3b:9bd2e859
Update Time : Wed Dec 30 18:28:22 2015
Checksum : 36091de2 - correct
Events : 0
Device Role : Active device 1
Array State : AA ('A' == active, '.' == missing, 'R' == replacing)
ralix ralph #
ralix ralph # mdadm -D /dev/md3
/dev/md3:
Version : 0.90
Creation Time : Sat May 9 22:58:18 2009
Raid Level : raid1
Array Size : 4294967295 (4096.00 GiB 4398.05 GB)
Used Dev Size : -1
Raid Devices : 2
Total Devices : 2
Preferred Minor : 3
Persistence : Superblock is persistent
Update Time : Wed Dec 30 18:31:31 2015
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
UUID : 9d3b4c33:07aaf76e:6aefa58e:ac893c19
Events : 0.447841
Number Major Minor RaidDevice State
0 8 17 0 active sync /dev/sdb1
1 8 33 1 active sync /dev/sdc1
ralix ralph #
ralix ralph # umount /mnt/test
ralix ralph # mdadm --stop /dev/md3
mdadm: stopped /dev/md3
ralix ralph # mdadm -A /dev/md3 /dev/sdb1 /dev/sdc1
mdadm: /dev/md3 has been started with 2 drives.
ralix ralph # mount /dev/md3 /mnt/test
mount: wrong fs type, bad option, bad superblock on /dev/md3,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so.
ralix ralph # mdadm -D /dev/md3
/dev/md3:
Version : 1.0
Creation Time : Sat May 9 22:58:19 2009
Raid Level : raid1
Array Size : 2147483647 (2048.00 GiB 2199.02 GB)
Used Dev Size : 2147483647 (2048.00 GiB 2199.02 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Wed Dec 30 18:28:22 2015
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Name : 3
UUID : 9d3b4c33:07aaf76e:6aefa58e:ac893c19
Events : 0
Number Major Minor RaidDevice State
0 8 17 0 active sync /dev/sdb1
1 8 33 1 active sync /dev/sdc1
ralix ralph # mdadm --stop /dev/md3
mdadm: stopped /dev/md3
ralix ralph # mdadm -A -e 0 /dev/md3 /dev/sdb1 /dev/sdc1
mdadm: /dev/md3 has been started with 2 drives.
ralix ralph # mdadm -D /dev/md3
/dev/md3:
Version : 0.90
Creation Time : Sat May 9 22:58:18 2009
Raid Level : raid1
Array Size : 4294967295 (4096.00 GiB 4398.05 GB)
Used Dev Size : -1
Raid Devices : 2
Total Devices : 2
Preferred Minor : 3
Persistence : Superblock is persistent
Update Time : Wed Dec 30 18:39:37 2015
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
UUID : 9d3b4c33:07aaf76e:6aefa58e:ac893c19
Events : 0.447841
Number Major Minor RaidDevice State
0 8 17 0 active sync /dev/sdb1
1 8 33 1 active sync /dev/sdc1
ralix ralph # mount /dev/md3 /mnt/test
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