Error creating Raid 5

[b1gnas]

Ok thank you :thumbup

[Jocko]

I reread your first post.

I assume that you want to copy data from sda8 to the raid as you build the raid in two phases.

So currently you can start to copy data without waiting that the raid is fully synchronized but of course in this case you need to wait for adding sda8 to the raid.

[b1gnas]

sda8 is empty

I think resync is too slow...

Code: Select all

root@fvdwsl-base:/ # cat /proc/mdstat
Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid5 sdb8[0] sde8[3] sdd8[2] sdc8[1]
      2920423872 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
      [=>...................]  resync =  9.8% (95730048/973474624) finish=451200.7min speed=32K/sec

While the raid is in this phase, can i try to format md0 again?

[Jocko]

Yes you can format md0 even if it is not fully synchronized

about sync speed, it is not a constant speed. So you can open mdstat several times to see how the speed change


Note: I am no longer here upto this evening

[b1gnas]

Hi,

i've decided to reinstall all from the beginning using 5.5 console.

now formatting the raid...

[b1gnas]

Hi Jocko, i need help again :dontknow

Code: Select all

root@fvdwsl-base:/ # umount /dev/md0
umount: /dev/md0: not mounted
root@fvdwsl-base:/ # mdadm --grow /dev/md0 --raid-devices=5
mdadm: Need to backup 768K of critical section..
mdadm: Cannot set device size/shape for /dev/md0: Device or resource busy

[Jocko]

Hi b1gnas,

i've decided to reinstall all from the beginning using 5.5 console.

I assumed that you wanted to build the raid5 directly with the 5 devices

As writing previously, build the raid5 in several steps is useful only if you want to copy data from existing partitions having to be included in the raid.

But we can continue your trial.

So what is the current status of your raid ? (=> cat /proc/mdstat).

[b1gnas]

No i've created the raid with 4 disks as you advised before...

Code: Select all

root@fvdwsl-base:/ # cat /proc/mdstat
Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid5 sda8[4](S) sdb8[0] sde8[3] sdd8[2] sdc8[1]
      2920423872 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
      [==>..................]  resync = 10.0% (98253120/973474624) finish=113051.9min speed=129K/sec
     
unused devices: <none>

Now i need to add sda8 (empty) to the raid

[Jocko]

Well the raid is not yet fully synchronize and indeed you don't have a fast speed :dry.

Currently our speed is lower than the default system speed (1000kB/s).
So you can try to improve it manually.

First post the output

Code: Select all

cat /sys/block/md0/md/sync_speed_min

and try to set a new value

Code: Select all

echo 100000 > /sys/block/md0/md/sync_speed_min

I'd rather you get a clean raid before growing it.

[b1gnas]

ok

Code: Select all

root@fvdwsl-base:/ # cat /sys/block/md0/md/sync_speed_min
1000 (system)

Code: Select all

root@fvdwsl-base:/ # cat /proc/mdstat
Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid5 sda8[4](S) sdb8[0] sde8[3] sdd8[2] sdc8[1]
      2920423872 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
      [==>..................]  resync = 10.0% (98253120/973474624) finish=251211.7min speed=58K/sec
     
unused devices: <none>

it's like the resync process is blocked...