[SOLVED!] My RAID5 broke...

Rasi · 2012-04-20 17:20:09

***Update***
this first post only tells the beginning.. watch #5 for momentary state of raid. i am totally out of ideas...

Hello.. i started a a scan process and had to hardreset my computer.
Now the raid is in resync mode and its AWFULLY slow:

md0 : active raid5 sdd1[3] sdb1[0] sdc1[1]
      3907025920 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/3] [UUU]
      [==>..................]  resync = 10.2% (200442656/1953512960) finish=10613.0min speed=2752K/sec

changing raid/speed_limit_min to a high number has absolutely NO effect. Speed remains the same.
Neither htop nor iotop show anything odd and dmesg is absolutely clean too. This cant be normal?
I had a resync on the very same system before, which was done in less than a day.

Last edited by Rasi (2012-04-20 21:07:26)

saharchie · 2012-04-20 17:25:33

have you run hdparm against the individual disks (sdb, sdc, sdd) ? if one of them is bad the reads will be horrible and may be the culprit to the slow resync.

Rasi · 2012-04-20 17:41:01

saharchie wrote:

have you run hdparm against the individual disks (sdb, sdc, sdd) ? if one of them is bad the reads will be horrible and may be the culprit to the slow resync.

hmm, sdd is REALLY slow...

/dev/sdb:
 Timing cached reads:   2390 MB in  2.00 seconds = 1195.48 MB/sec
 Timing buffered disk reads: 342 MB in  3.01 seconds = 113.76 MB/sec
[root@archnas carnager]# hdparm -tT /dev/sda

/dev/sdc:
 Timing cached reads:   2416 MB in  2.00 seconds = 1208.05 MB/sec
 Timing buffered disk reads: 332 MB in  3.01 seconds = 110.44 MB/sec

/dev/sdd:
 Timing cached reads:   1996 MB in  2.00 seconds = 998.23 MB/sec
 Timing buffered disk reads:  14 MB in  3.07 seconds =   4.57 MB/sec

Last edited by Rasi (2012-04-20 17:41:13)

saharchie · 2012-04-20 17:52:32

optomistically you could try swapping SATA cable and try again, but more than likely that disk needs to be replaced.

Rasi · 2012-04-20 19:14:00

I just did a reboot and now the raid seems to be completely dead.
Strangely the slow drive is the only one that is recognised.

http://paste.xinu.at/wmgB/

saharchie · 2012-04-20 20:30:45

ugh .... it looks like sdb1 and sdc1 were assigned 'spare' roles, and I'm thinking this is good actually.

i'm not exactly 100% sure of the best way forward and i'm thinking you might have to manually fail/remove sdd1 and then re-activate sdb1/sdc1

.... or maybe try to re-create the entire raid but specify 'missing' for sdd1 z.B:

mdadm --create /dev/md0 --assume-clean --level=5 --raid-devices=3 /dev/sdb1 /dev/sdc1 missing

I'm fairly certain your data is sill there and i'm fairly certain that /dev/sdd is dying ... i'd double-check any mdadm documentation too

...sorry i can't be much more help

Rasi · 2012-04-20 21:04:18

Oh yes.. thank you so much, i see my data. That command was 100% what i needed.

Now i turn off my NAS and leave it off until i have a new harddisk

Last edited by Rasi (2012-04-20 23:45:46)

saharchie · 2012-04-20 21:15:55

awesome

edit: i can't read ... glad you're back in business

Last edited by saharchie (2012-04-21 02:46:13)

Rasi · 2012-04-24 13:53:05

for some reason the device name changed from md0 to archnas-0 but apart from that the raid is rebuilding now at proper speeds. Thanks again

Last edited by Rasi (2012-04-24 14:09:11)

Arch Linux

#1 2012-04-20 17:20:09

[SOLVED!] My RAID5 broke...

#2 2012-04-20 17:25:33

Re: [SOLVED!] My RAID5 broke...

#3 2012-04-20 17:41:01

Re: [SOLVED!] My RAID5 broke...

#4 2012-04-20 17:52:32

Re: [SOLVED!] My RAID5 broke...

#5 2012-04-20 19:14:00

Re: [SOLVED!] My RAID5 broke...

#6 2012-04-20 20:30:45

Re: [SOLVED!] My RAID5 broke...

#7 2012-04-20 21:04:18

Re: [SOLVED!] My RAID5 broke...

#8 2012-04-20 21:15:55

Re: [SOLVED!] My RAID5 broke...

#9 2012-04-24 13:53:05

Re: [SOLVED!] My RAID5 broke...

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