Hi,
I just finished converting a 3-disk raid5 to 4-disk raid6. After a
reboot to start clean, I noticed that one of the disk (the new one I
just added) was missing in /proc/partitions. This was disk 4 in my
/dev/md0. Assuming some cable issue, I powered off, wiggled the cables
and restarted and the device was found by kernel. However, md0 shows
device missing and array degraded
lata [rramesh] 280 > cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md0 : active raid6 sdb1[0] sdd1[3] sdc1[1]
3906763776 blocks super 1.2 level 6, 512k chunk, algorithm 2
[4/3] [UUU_]
unused devices: <none>
However my attempt to --re-add does not work.
lata [rramesh] 277 > sudo mdadm /dev/md0 --verbose --re-add /dev/sde1
mdadm: --re-add for /dev/sde1 to /dev/md0 is not possible
lata [rramesh] 278 > sudo mdadm -E /dev/sde1
/dev/sde1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 730051d9:f4c58e0c:504fd1d9:798a84a4
Name : lata:0 (local to host lata)
Creation Time : Sun Oct 6 16:41:01 2013
Raid Level : raid6
Raid Devices : 4
Avail Dev Size : 5860268943 (2794.39 GiB 3000.46 GB)
Array Size : 3906763776 (3725.78 GiB 4000.53 GB)
Used Dev Size : 3906763776 (1862.89 GiB 2000.26 GB)
Data Offset : 262144 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 03898148:47c40cc2:f365082e:9f7f06cf
Update Time : Thu Aug 14 08:53:16 2014
Checksum : 346e9226 - correct
Events : 1191488
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 3
Array State : AAAA ('A' == active, '.' == missing)
lata [rramesh] 279 > fgrep UUID /etc/mdadm/mdadm.conf
# ARRAY /dev/md/0 metadata=1.2
UUID=0e9f76b5:4a89171a:a930bccd:78749144 name=zym:0
ARRAY /dev/md0 metadata=1.2 spares=1 name=lata:0
UUID=730051d9:f4c58e0c:504fd1d9:798a84a4
I checked the SMART and it shows a lot of reallocated_sector_ct errors
also. So, the disk is dying, but I am not able understand why mdadm
would not add.
SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE
UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x000b 091 091 016 Pre-fail
Always - 53
2 Throughput_Performance 0x0005 100 100 054 Pre-fail
Offline - 0
3 Spin_Up_Time 0x0007 135 135 024 Pre-fail
Always - 426 (Average 425)
4 Start_Stop_Count 0x0012 100 100 000 Old_age
Always - 59
*5 Reallocated_Sector_Ct 0x0033 001 001 005 Pre-fail
Always FAILING_NOW 330*
7 Seek_Error_Rate 0x000b 098 098 067 Pre-fail
Always - 2
8 Seek_Time_Performance 0x0005 100 100 020 Pre-fail
Offline - 0
9 Power_On_Hours 0x0012 100 100 000 Old_age
Always - 3445
10 Spin_Retry_Count 0x0013 100 100 060 Pre-fail
Always - 0
12 Power_Cycle_Count 0x0032 100 100 000 Old_age
Always - 59
192 Power-Off_Retract_Count 0x0032 100 100 000 Old_age
Always - 548
193 Load_Cycle_Count 0x0012 100 100 000 Old_age
Always - 548
194 Temperature_Celsius 0x0002 153 153 000 Old_age
Always - 39 (Min/Max 21/43)
196 Reallocated_Event_Count 0x0032 001 001 000 Old_age
Always - 17604
197 Current_Pending_Sector 0x0022 001 001 000 Old_age
Always - 13256
198 Offline_Uncorrectable 0x0008 100 100 000 Old_age
Offline - 0
199 UDMA_CRC_Error_Count 0x000a 200 200 000 Old_age
Always - 0
Any recommendations while I am waiting to get a replacement.
Ramesh
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