Error creating Raid 5

[Jocko]

Indeed sync seems to be blocked.

can you try this:

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

stop the current sync:
echo idle > /sys/block/md0/md/sync_action

restart sync
echo repair > /sys/block/md0/md/sync_action


[b1gnas]

Hi,

i'm still here... and the nas is resyncing (restarted many times)

i can't stop it

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root@fvdwsl-base:/ # echo idle > /sys/block/md0/md/sync_action
root@fvdwsl-base:/ # cat /sys/block/md0/md/sync_action
resync


i tried to execute this command

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mdadm --manage /dev/md0 --add /dev/sda8

and now sda8 is included in the raid

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root@fvdwsl-base:/ # cat /proc/mdstat
Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid5 sdb8[0] sda8[4](S) sde8[3] sdd8[2] sdc8[1]
      2920423872 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
      [=>...................]  resync =  9.3% (90997536/973474624) finish=855.2min speed=17196K/sec

unused devices: <none>


but then

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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


however the resync speed now is good, so may be it will finish this time :roll:

[Jocko]

Hi b1gnas,

About the error message "device or resource busy", I am pretty sure that it is the noflush daemon that occurs it. (I already noted this). So you need to kill it before growing the raid

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killall noflushd

[b1gnas]

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root@fvdwsl-base:/ # killall noflushd
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]

So see what happens after synchronizing fully md0 as it is not the same synchronization when you grow a RAID.

[b1gnas]

After a day

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root@fvdwsl-base:/ # cat /proc/mdstat
Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid5 sdb8[0] sda8[4](S) sde8[3] sdd8[2] sdc8[1]
      2920423872 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
      [========>............]  resync = 42.9% (418269184/973474624) finish=1656368.6min speed=5K/sec

unused devices: <none>


then i removed sda8 and tried to stop the resync but now it's stucked here

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root@fvdwsl-base:/ # mdadm --remove /dev/md0 /dev/sda8
mdadm: hot removed /dev/sda8
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 = 42.9% (418269184/973474624) finish=1667110.0min speed=5K/sec

unused devices: <none>
root@fvdwsl-base:/ # mdadm --detail /dev/md0
/dev/md0:
        Version : 00.90.03
  Creation Time : Sat Jun  6 21:47:00 2015
     Raid Level : raid5
     Array Size : 2920423872 (2785.13 GiB 2990.51 GB)
    Device Size : 973474624 (928.38 GiB 996.84 GB)
   Raid Devices : 4
  Total Devices : 4
Preferred Minor : 0
    Persistence : Superblock is persistent

    Update Time : Tue Jun 23 10:19:47 2015
          State : active, resyncing
 Active Devices : 4
Working Devices : 4
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 64K

 Rebuild Status : 42% complete

           UUID : 7c24e3bd:dcb477ad:840c657b:d038b41e
         Events : 0.293

    Number   Major   Minor   RaidDevice State
       0       8       56        0      active sync   /dev/sdb8
       1       8       40        1      active sync   /dev/sdc8
       2       8       24        2      active sync   /dev/sdd8
       3       8        8        3      active sync   /dev/sde8
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 = 42.9% (418269184/973474624) finish=1667772.3min speed=5K/sec

unused devices: <none>
root@fvdwsl-base:/ # echo idle > /sys/block/md0/md/sync_action



i would like to try to reinstall original lacie firmware to see if it works again...

[Jocko]

Hi b1gnas,

I don't understand why you have this low speed...

i would like to try to reinstall original lacie firmware to see if it works again...

You can find guidance here: http://forum.nas-central.org/viewtopic. ... 1&start=30

[b1gnas]

I can only get to work a 4 disks RAID 5, after adding sda8 i always have a very low speed recovery...

[Jocko]

Hi b1gnas,

Currently I don't understand well your issue.

With the last kernel version, you succeed to create a raid (set, format it and synchronize the raid members) only if the partitions table is an EFI gpt table.
for me, you should be able to use msdos partitions table on these disks as their size is lower then 2TB. But tests show that you fail in this case. :scratch

Then the issue is sda disk must use msdos table as uboot does not support efi gpt table. (Need to deepen this point to get a workaround)

To check if low sync speed is another issue you can do it :
- add sda8 as a spare disk
- set an active raid member as a faulty disk:

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mdadm /dev/md0 -f /dev/sdb8

(I assume that you use sdb8 as faulty disk)

Then mdadm shoould try to use sda8 instead of sdb8 and see if you still have a low speed.

[b1gnas]

Hi Jocko,
it's samrise that has gpt tables, my problem is different... i have all msdos tables but it works only a 4 disks RAID5, if i add the fifth disk i have the same problem described in my old post viewtopic.php?f=30&t=2168&start=90