Hi,
I have a 6 device raid 5 array which had 1 disk go bad and then due to a
power outage, the machine shutdown and when it started all the disks were
showing up as spares with the following mdadm -E output (sample for one
given below and full for all devices attached).
This md device was part a Physical Volume for a LVM Volume Group.
I am trying to recreate the array using mdadm --create --assume-clean using
1 device as missing. I am checking if the device is getting created
correctly by checking the UUID of the created device which would match if
the device gets created correctly.
I have tried a few combinations of the disk order that I believe is right
however I think I'm getting tripped up by the fact that the mdadm I used to
create this md device was some 2.x series and now we are on 3.x (and I may
have taken some of the defaults originally which I don't' remember)
What all 'defaults' have changed over the versions so I can try those? Like
chunk size? Can we manually configure the super/data offset? Are those
significant when we do an mdadm --create --assume-clean?
Thanks,
Anshu
/dev/sda5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : b480fe0c:c9e29256:0fcf1b0c:1f8c762c
Name : GATEWAY:RAID5_500G
Creation Time : Wed Apr 28 16:10:43 2010
Raid Level : -unknown-
Raid Devices : 0
Avail Dev Size : 976768002 (465.76 GiB 500.11 GB)
Used Dev Size : 976765954 (465.76 GiB 500.10 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : active
Device UUID : a8499a91:628ddde8:1cc8f4b9:749136f9
Update Time : Sat May 19 23:04:23 2012
Checksum : 9950883c - correct
Events : 1
Device Role : spare
Array State : ('A' == active, '.' == missing)
/dev/sda5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : b480fe0c:c9e29256:0fcf1b0c:1f8c762c
Name : GATEWAY:RAID5_500G
Creation Time : Wed Apr 28 16:10:43 2010
Raid Level : -unknown-
Raid Devices : 0
Avail Dev Size : 976768002 (465.76 GiB 500.11 GB)
Used Dev Size : 976765954 (465.76 GiB 500.10 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : active
Device UUID : a8499a91:628ddde8:1cc8f4b9:749136f9
Update Time : Sat May 19 23:04:23 2012
Checksum : 9950883c - correct
Events : 1
Device Role : spare
Array State : ('A' == active, '.' == missing)
/dev/sdb5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : b480fe0c:c9e29256:0fcf1b0c:1f8c762c
Name : GATEWAY:RAID5_500G
Creation Time : Wed Apr 28 16:10:43 2010
Raid Level : -unknown-
Raid Devices : 0
Avail Dev Size : 976765954 (465.76 GiB 500.10 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : active
Device UUID : 6a8b21d9:db53ca34:5c9a1baa:5e5782ae
Update Time : Sat May 19 23:04:23 2012
Checksum : d237209e - correct
Events : 1
Device Role : spare
Array State : ('A' == active, '.' == missing)
/dev/sdc5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : b480fe0c:c9e29256:0fcf1b0c:1f8c762c
Name : GATEWAY:RAID5_500G
Creation Time : Wed Apr 28 16:10:43 2010
Raid Level : -unknown-
Raid Devices : 0
Avail Dev Size : 976767730 (465.76 GiB 500.11 GB)
Used Dev Size : 976765954 (465.76 GiB 500.10 GB)
Data Offset : 272 sectors
Super Offset : 8 sectors
State : active
Device UUID : f6a10896:453db503:6ee797f6:c3e82660
Update Time : Sat May 19 23:04:23 2012
Checksum : 5c29ff09 - correct
Events : 1
Device Role : spare
Array State : ('A' == active, '.' == missing)
/dev/sdd5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : b480fe0c:c9e29256:0fcf1b0c:1f8c762c
Name : GATEWAY:RAID5_500G
Creation Time : Wed Apr 28 16:10:43 2010
Raid Level : -unknown-
Raid Devices : 0
Avail Dev Size : 976765954 (465.76 GiB 500.10 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : active
Device UUID : 556895ef:d6837868:2cca2c17:419725e9
Update Time : Sat May 19 23:04:23 2012
Checksum : c40d9d33 - correct
Events : 1
Device Role : spare
Array State : ('A' == active, '.' == missing)
/dev/sde5:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : b480fe0c:c9e29256:0fcf1b0c:1f8c762c
Name : GATEWAY:RAID5_500G
Creation Time : Wed Apr 28 16:10:43 2010
Raid Level : -unknown-
Raid Devices : 0
Avail Dev Size : 976765954 (465.76 GiB 500.10 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : active
Device UUID : e5e08b73:78b52879:09aa765e:17005a82
Update Time : Sat May 19 23:04:23 2012
Checksum : 3932901d - correct
Events : 1
Device Role : spare
Array State : ('A' == active, '.' == missing)
