One other point sda isn't the boot hard drive, that's the partitions /sdb1
and sdc1, but these should be the same (I thought I'd mirrored them to be
honest).
I tried mdadm --detail /dev/sdd1 but it didn't work. I have these results
if they help?
/dev/md1:
Version : 1.2
Creation Time : Thu Jan 31 22:43:49 2013
Raid Level : raid1
Array Size : 1953510841 (1863.01 GiB 2000.40 GB)
Used Dev Size : 1953510841 (1863.01 GiB 2000.40 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Tue Jul 2 13:49:55 2013
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : Hawaiian:1 (local to host Hawaiian)
UUID : a544829f:33778728:79870439:241c5c51
Events : 112
Number Major Minor RaidDevice State
0 0 0 0 removed
1 8 65 1 active sync /dev/sde1
/dev/md127:
Version : 1.2
Creation Time : Thu Jan 31 22:43:49 2013
Raid Level : raid1
Array Size : 1953510841 (1863.01 GiB 2000.40 GB)
Used Dev Size : 1953510841 (1863.01 GiB 2000.40 GB)
Raid Devices : 2
Total Devices : 1
Persistence : Superblock is persistent
Update Time : Tue Jul 2 13:49:29 2013
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Name : Hawaiian:1 (local to host Hawaiian)
UUID : a544829f:33778728:79870439:241c5c51
Events : 106
Number Major Minor RaidDevice State
0 8 49 0 active sync /dev/sdd1
1 0 0 1 removed
How should I proceed from here?
James
On 2 July 2013 09:50, James Allsopp <[email protected]> wrote:
> Thanks Bob, I'll get back to after I've followed your instructions. I
> think I'm going to have to learn to type with crossed fingers!
>
> I think I initially sorted out all my partitions manually, rather than
> directly using the installer to do it automatically,
> Really appreciated,
> James
>
>
> On 2 July 2013 00:46, Bob Proulx <[email protected]> wrote:
>
>> James Allsopp wrote:
>> > Personalities : [raid0] [raid1] [raid6] [raid5] [raid4]
>> > md126 : active raid1 sdb3[0] sdc3[1]
>> > 972550912 blocks [2/2] [UU]
>>
>> So sdb3 and sdc3 are assembled into /dev/md126. That seems good. One
>> full array is assembled.
>>
>> Is /dev/md126 your preferred name for that array? I would guess not.
>> Usually it is /dev/md0 or some such. But when that name is not
>> available because it is already in use then mdadm will rotate up to a
>> later name like /dev/md126.
>>
>> You can fix this by using mdadm with --update=super-minor to force it
>> back to the desired name. Something like this using your devices:
>>
>> mdadm --assemble /dev/md0 --update=super-minor /dev/sdb3 /dev/sdc3
>>
>> But that can only be done at assembly time. If it is already
>> assembled then you would need to stop the array first and then
>> assemble it again.
>>
>> > md127 : active raid1 sdd1[0]
>> > 1953510841 blocks super 1.2 [2/1] [U_]
>> >
>> > md1 : active raid1 sde1[1]
>> > 1953510841 blocks super 1.2 [2/1] [_U]
>>
>> I think this array is now has a split brain problem. At this point
>> the original single mirrored array has had both halves of the mirror
>> assembled and both are running. So now you have two clones of each
>> other and both are active. Meaning that each think they are newer
>> than the other. Is that right? In which case you will eventually
>> need to pick one and call it the master. I think the sde1 is the
>> natural master since it is assembled on /dev/md1.
>>
>> > cat /etc/mdadm/mdadm.conf
>> > ...
>> > # definitions of existing MD arrays
>> > ARRAY /dev/md0 UUID=a529cd1b:c055887e:bfe78010:bc810f04
>>
>> Only one array specified. That is definitely part of your problem.
>> You should have at least two arrays specified there.
>>
>> > mdadm --detail --scan:
>> >
>> > ARRAY /dev/md/0_0 metadata=0.90 UUID=a529cd1b:c055887e:bfe78010:bc810f04
>>
>> That mdadm --scan only found one array is odd.
>>
>> > fdisk -l
>> >
>> > Disk /dev/sda: 120.0 GB, 120033041920 bytes
>> > 255 heads, 63 sectors/track, 14593 cylinders
>> > Units = cylinders of 16065 * 512 = 8225280 bytes
>> > Sector size (logical/physical): 512 bytes / 512 bytes
>> > I/O size (minimum/optimal): 512 bytes / 512 bytes
>> > Disk identifier: 0x0002ae52
>> >
>> > Device Boot Start End Blocks Id System
>> > /dev/sda1 1 14593 117218241 83 Linux
>>
>> I take it that this is your boot disk? Your boot disk is not RAID?
>>
>> I don't like that the first used sector is 1. That would have been 63
>> using the previous debian-installer to leave space for the MBR and
>> other things. But that is a different issue.
>>
>> > Disk /dev/sdd: 2000.4 GB, 2000398934016 bytes
>> > 255 heads, 63 sectors/track, 243201 cylinders
>> > Units = cylinders of 16065 * 512 = 8225280 bytes
>> > Sector size (logical/physical): 512 bytes / 4096 bytes
>> > I/O size (minimum/optimal): 4096 bytes / 4096 bytes
>> ^^^^ ^^^^
>>
>> That is an Advanced Format 4k sector drive. Meaning that the
>> partitions should start on a 4k sector alignment. The
>> debian-installer would do this automatically.
>>
>> > Disk identifier: 0xe044b9be
>> >
>> > Device Boot Start End Blocks Id System
>> > /dev/sdd1 1 243201 1953512001 fd Linux raid
>> autodetect
>> ^^^^^
>> > /dev/sde1 1 243201 1953512001 fd Linux raid
>> autodetect
>> ^^^^^
>> > Partition 1 does not start on physical sector boundary.
>>
>>
>> I don't recall if the first sector is 0 or 1 but I think the first
>> sector is 0 for the partition table. Meaning that sector 1 is not
>> going to be 4k aligned. (Can someone double check me on this?)
>> Meaning that this will require a lot of read-modify-write causing
>> performance problems for those drives.
>>
>> The new standard for sector alignment would start at 2048 to leave
>> space for the partition table and other things and still be aligned
>> properly.
>>
>> > I don't know if this helps or where to go from here, but I think I need
>> to
>> > get the mdadm up and running properly before I do anything.
>>
>> Probably a good idea.
>>
>> > If there's any commands you need me to run, please ask,
>>
>> How are you booted now? Are you root on the system through something
>> like the debian-installer rescue boot? Or did you use a live cd or
>> something?
>>
>> Please run:
>>
>> # mdadm --detail /dev/sdd1
>> # mdadm --detail /dev/sde1
>>
>> Those are what look to be the split brain of the second array. They
>> will list something at the bottom that will look like:
>>
>> Number Major Minor RaidDevice State
>> this 1 8 17 1 active sync /dev/sdb1
>>
>> 0 0 8 1 0 active sync /dev/sda1
>> 1 1 8 17 1 active sync /dev/sdb1
>>
>> Except in your case each will list one drive and will probably have
>> the other drive listed as removed. But importantly it will list the
>> UUID of the array in the listing.
>>
>> Magic : a914bfec
>> Version : 0.90.00
>> UUID : b8eb34b1:bcd37664:2d9e4c59:117ab348
>> Creation Time : Fri Apr 30 17:21:12 2010
>> Raid Level : raid1
>> Used Dev Size : 497856 (486.27 MiB 509.80 MB)
>> Array Size : 497856 (486.27 MiB 509.80 MB)
>> Raid Devices : 2
>> Total Devices : 2
>> Preferred Minor : 0
>>
>> Check each physical volume and verify that the UUID and other stats
>> verify that the same array has been forked and is running on both.
>> The data in that header should be the same for both halves of the
>> cloned and split mirror.
>>
>> Corrective Action:
>>
>> I _think_ you should stop the array on /dev/md127. Then add that disk
>> to the array running on /dev/md1. Don't do this until you have
>> confirmated that the two drives are clones of each other. If they are
>> split then you need to join them. I think something like this:
>>
>> mdadm --stop /dev/md127
>> mdadm --manage /dev/md1 --add /dev/sdd1
>>
>> Be sure to double check all of my device nodes and agree with those
>> before you do these commands. But I think those are what you want to
>> do. That will basically destroy anything what is currently sdd1 and
>> sync sde1 upon sdd1.
>>
>> At that point you should have both arrays running. You could stop
>> there and live with /dev/md126 but I think you want to fix the device
>> minor numbering on /dev/md126 by stopping the array and assembling it
>> again with the correct name.
>>
>> mdadm --stop /dev/md126
>> mdadm --assemble /dev/md0 --update=super-minor /dev/sdb1 /dev/sdc1
>>
>> At that point you should have two arrays up and running on /dev/md0
>> and /dev/md1 and both should have the low level lvm physical volumes
>> needed to assemble the lvm volume groups. Run the --scan again.
>>
>> mdadm --detail --scan
>>
>> Any errors at this time? Hopefully it will list two arrays. If not
>> then something is still wrong. Here are some additional commands to
>> get the same information anyway.
>>
>> mdadm --detail /dev/md0
>> mdadm --detail /dev/md1
>>
>> mdadm --examine /dev/sdb3
>> mdadm --examine /dev/sdc3
>>
>> mdadm --examine /dev/sdd1
>> mdadm --examine /dev/sde1
>>
>> If that turns out favorable then edit the /etc/mdadm/mdadm.conf file
>> and update the list of ARRAY lines there. I don't have the UUID
>> numbers from your system so can't suggest anything. But the above
>> will list out the UUID numbers for the arrays. Use them to update the
>> mdadm.conf file.
>>
>> Then after updating that file update the initramfs. I usually
>> recommend using dpkg-reconfigure of the current kernel package. But
>> using 'update-initramfs -u' if you want is okay too. The important
>> concept is that the initrd needs to be rebuilt including the new
>> arrays as listed in mdadm.conf so that the arrays are assembled at
>> initramfs time.
>>
>> dpkg-reconfigure linux-image-$(uname -r)
>>
>> At this point if everything worked then you should be good to go. I
>> would cross your fingers and reboot. If all is good then it should
>> reboot okay.
>>
>> Just as additional debug, after having both arrays up and online then
>> you can activate the lvm manually. I would probably try letting the
>> system reboot first. But just as low-level commands to further debug
>> things as hints of where to look next in case they might be needed.
>>
>> modprobe dm-mod
>> vgscan
>> vgchange -aly
>>
>> That should activate the LVM. You should have devices in
>> /dev/mapper/* corresponding to them. You should be able to see a
>> listing of the logical volumes on the system.
>>
>> lvs
>>
>> Good luck!
>> Bob
>>
>
>
