Sorry for the late response.
On Sat, Jun 15, 2013 at 1:07 AM, Bob Proulx <b...@proulx.com> wrote:
> Muhammad Yousuf Khan wrote:
> > one of our server's drive failed due to power cord issue.
> > however i plug it back and due to less experience with "parted" i messed
> > the whole thing.
>
> If it was a power cord issue, and you plugged it back in, then there
> should be no need to use parted. Simply mdadm re-add the drive to the
> raid array. If the drive was running correctly before then the
> partitions on the drive would have been correct. There should be no
> need to make any changes to the partition table.
>
> > i have 2tbx2 RAID 1 mirror
>
> Nice box.
>
> Thanks :)
> > and have 4x500GB partitions.
>
> And understand that each of those partitions are set up as RAID 1 mirror.
>
> > even i selected the right drive by "select command" and deleted the right
> > partition but parted did something worst though, i take it as my own
> > mistake as i am not that experience with parted i am usually using fdisk.
>
> Why were you trying to delete, add, or modify any partition? You said
> you had a power cord issue. Did you replace the disk with a different
> disk? If you replaced the disk with a different disk then you will
> need to clone the partition table. If you are using the same disk as
> before then do not modify the partition table.
>
actually i did that by mistake :)
>
> > now the problem part is i can not re attach the fail drive partition with
> > RAID /dev/md[2,3,4] devices.
> >
> > Personalities : [raid1]
> > md1 : active (auto-read-only) raid1 sdc1[0]
> > 488147776 blocks super 1.2 [2/1] [U_]
> >
> > md4 : active raid1 sdb4[0]
> > 488670072 blocks super 1.2 [2/1] [U_]
> >
> > md3 : active raid1 sdb3[0]
> > 488279928 blocks super 1.2 [2/1] [U_]
> >
> > md2 : active raid1 sdb2[0]
> > 488279928 blocks super 1.2 [2/1] [U_]
>
> This shows two devices. It shows /dev/sdb and /dev/sdc. All four
> raid partitions are operating in degraded mode using only one device.
> Note that the sizes are not quite identical.
>
> But that is only part of the data. You need to use mdadm to display
> the data that you need. Please show the output of each of the following
> commands:
>
> mdadm --detail /dev/md1
> mdadm --detail /dev/md2
> mdadm --detail /dev/md3
> mdadm --detail /dev/md4
>
>
root@nasbox:~# mdadm --detail /dev/md1
/dev/md1:
Version : 1.2
Creation Time : Thu Jun 13 23:46:28 2013
Raid Level : raid1
Array Size : 488147776 (465.53 GiB 499.86 GB)
Used Dev Size : 488147776 (465.53 GiB 499.86 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Thu Jun 13 23:46:28 2013
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Number Major Minor RaidDevice State
0 8 33 0 active sync /dev/sdc1
1 0 0 1 removed
root@nasbox:~# mdadm --detail /dev/md2
/dev/md2:
Version : 1.2
Creation Time : Wed May 9 20:19:59 2012
Raid Level : raid1
Array Size : 488279928 (465.66 GiB 500.00 GB)
Used Dev Size : 488279928 (465.66 GiB 500.00 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Fri Jun 21 17:20:34 2013
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : archive:2
UUID : c417ee7a:ad1eedf5:73043caa:e15bceb3
Events : 3320
Number Major Minor RaidDevice State
0 8 18 0 active sync /dev/sdb2
1 0 0 1 removed
root@nasbox:~# mdadm --detail /dev/md3
/dev/md3:
Version : 1.2
Creation Time : Wed May 9 20:20:11 2012
Raid Level : raid1
Array Size : 488279928 (465.66 GiB 500.00 GB)
Used Dev Size : 488279928 (465.66 GiB 500.00 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Fri Jun 21 12:38:13 2013
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : archive:3
UUID : 6e63959f:b2947908:46bbbe04:211639f6
Events : 6206
Number Major Minor RaidDevice State
0 8 19 0 active sync /dev/sdb3
1 0 0 1 removed
root@nasbox:~# mdadm --detail /dev/md4
/dev/md4:
Version : 1.2
Creation Time : Wed May 9 20:39:03 2012
Raid Level : raid1
Array Size : 488670072 (466.03 GiB 500.40 GB)
Used Dev Size : 488670072 (466.03 GiB 500.40 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Fri Jun 21 12:38:13 2013
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : archive:4
UUID : cdb71a07:2a18cc4a:bf139b42:a819fab1
Events : 3434
Number Major Minor RaidDevice State
0 8 20 0 active sync /dev/sdb4
1 0 0 1 removed
root@nasbox:~#
> The critical information is at the bottom of each of the output. On
> my system it shows this for an example:
>
> Number Major Minor RaidDevice State
> 0 8 1 0 active sync /dev/sda1
> 1 8 17 1 active sync /dev/sdb1
>
my second line state "Removed" :(
> You will need to know that information in order to proceed successfully.
> I would like to see the output of:
>
> mdadm --examine /dev/sdc2
>
root@nasbox:~# mdadm --examine /dev/sdc2
mdadm: No md superblock detected on /dev/sdc2.
>
> I am hoping that would show something useful. I would also like to
> see the exact sizes of the partitions. Please show the output of the
> following which will show the exact sizes. I worry that sdc2 is not
> large enough and is smaller than sdb2.
>
> sfdisk -d /dev/sdb
> sfdisk -d /dev/sdc
>
>
root@nasbox:~# sfdisk -d /dev/sdb
WARNING: GPT (GUID Partition Table) detected on '/dev/sdb'! The util sfdisk
doesn't support GPT. Use GNU Parted.
# partition table of /dev/sdb
unit: sectors
/dev/sdb1 : start= 1, size=3907029167, Id=ee
/dev/sdb2 : start= 0, size= 0, Id= 0
/dev/sdb3 : start= 0, size= 0, Id= 0
/dev/sdb4 : start= 0, size= 0, Id= 0
root@nasbox:~# sfdisk -d /dev/sdc
read: Input/output error
sfdisk: read error on /dev/sdc - cannot read sector 0
/dev/sdc: unrecognized partition table type
No partitions found
root@nasbox:~#
> It is possible that the partition table on the disk and the operating
> system's view of it are out of sync with each other. You may need to
> poke at the OS and have it scan the disk.
>
> partprobe /dev/sdc
>
>
> Hope that helps.
> Bob
>
Thanks bob for all your interest. :)
