After setup, cat /proc/mdstat output looks like this:
proxmox:~# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 sdc2[1] sdb2[0]
293024832 blocks [2/2] [UU]
unused devices: <none>
Also, after I setup raid1 fresh, i got the following:
proxmox:~# mdadm --examine --scan
ARRAY /dev/md0 level=raid1 num-devices=2 UUID=fbda4051:61cbc27f:7f2b1f39:e153e83f
But, after reboot, cat /proc/mdstat outputs:
proxmox:~# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active (auto-read-only) raid1 sdc[1]
293024832 blocks [2/1] [_U]
unused devices: <none>
Why is it using sdc1 now?
Also, now I get:
proxmox:~# mdadm --examine --scan
ARRAY /dev/md0 level=raid1 num-devices=2 UUID=fbda4051:61cbc27f:7f2b1f39:e153e83f
ARRAY /dev/md0 level=raid1 num-devices=2 UUID=fbda4051:61cbc27f:9822ee23:9b948649
proxmox:~# dmesg | grep md0
md/raid1:md0: active with 1 out of 2 mirrors
md0: detected capacity change from 0 to 300057427968
md0: p1 p2
md0: p2 size 586049840 exceeds device capacity, limited to end of disk
Where did the two partition on /dev/md0 come from? I never made them.
Also, sdc1 and sdc2 aren't listed in the /dev tree.
Here is the fdisk output:
proxmox:~# fdisk -l /dev/sdb
Disk /dev/sdb: 300.0 GB, 300069052416 bytes
255 heads, 63 sectors/track, 36481 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x3bd84a48
Device Boot Start End Blocks Id System
/dev/sdb1 1 2 10240 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sdb2 2 36482 293024920 fd Linux raid autodetect
Partition 2 does not end on cylinder boundary.
proxmox:~# fdisk -l /dev/sdc
Disk /dev/sdc: 300.0 GB, 300069052416 bytes
255 heads, 63 sectors/track, 36481 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x371c8012
Device Boot Start End Blocks Id System
/dev/sdc1 1 2 10240 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sdc2 2 36482 293024920 fd Linux raid autodetect
Partition 2 does not end on cylinder boundary.
A bit of info: Server running Proxmox v1.9, which is debian lenny 64bit. sda is the system hard drive (hard ware RAID).
sdb and sdc are 300GB brand new Raptor drives.
Best Answer
First off, check the physical hardware like connections, cables, and correctly-seated cards. For the disk itself, check SMART data on /dev/sdb to make sure the disk itself is not failing out periodically. Western Digital Raptors are fast but prone to failure, I've had one fail on me out of nowhere (not even SMART data predicted it). Use smartctl to read the SMART data and run tests. It comes in the smartmontools package:
Pull the data and look for anomalies or errors logged:
Finally, run a manual self-test, which will take about 2 minutes.
longcan be substituted forshort, and is more thorough, but it takes far longer ("tens of minutes"):Once the test is done, review the results:
If it all comes back clean, you can move on to debugging the mdadm stack.
Your partition arrangement is a bit strange on the RAID devices. If those devices will be dedicated to RAID, you don't need a partition table at all. Assuming there's no data, you'd be well advised to keep it simple and use the block devices directly. In fdisk they would show up like this:
To eliminate any issues with partitioning and start from scratch, just dd some zeros at the beginning of each disk;
Repeat for /dev/sdc. Create the array using those two devices:
Don't forget to check dmesg for any disk-related output!