Preventative replacement of active RAID1 disks
flat view
From: Jan Ceuleers <hidden>
Date: 2012-01-18 17:04:16
List,
I have two 2-partition RAID1 sets, each with a spare. The SMART info for both active disks suggests that I should replace them. Both of them. I based this on the Seek_Error_Rate in the smartctl -a output (below).
I am looking for advice on how best to do this.
root@zotac:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md0 : active raid1 sde1[1] sdb2[2](S) sdd1[0]
521984 blocks [2/2] [UU]
md1 : active raid1 sde2[1] sdd2[0] sdb3[2](S)
487861824 blocks [2/2] [UU]
unused devices: <none>
root@zotac:~# mdadm -V
mdadm - v2.6.7.1 - 15th October 2008
root@zotac:~# uname -a
Linux zotac 2.6.35-31-generic #63-Ubuntu SMP Mon Nov 28 19:29:10 UTC 2011 x86_64 GNU/Linux
Here are my constraints:
- I have space in the enclosure for one additional drive (not two).
- Given that both drives are potentially flaky I don't want any period of time during which there is a single point of failure.
- I would like the partition which is currently the spare to remain the spare, although that does not need to be the case at all times.
- I do not have hot-swap capability, so each time I add or remove a drive I need to shut down and reboot afterwards.
I've got two new drives. So I think the steps I should take are as follows; comments welcome.
1. Install the first new drive in the cabinet. Create partitions whose size is compatible with the current RAID sets.
2. For each of the two RAIDs, mdadm /dev/mdX --add /dev/sdfY the new partitions to the respective md sets.
3. Increase the number of active devices from 2 to 3 (or to 4?), thereby forcing a resync. I.e. mdadm --grow /dev/mdX --raid-devices=3 or 4. Wait for completion.
Here I'm not sure what to do. If I increase the number of active devices to 4 then I'm sure that all partitions contain valid data. Is this necessary? If I go from two to three active devices, can I tell mdadm which of the two available spares to make active?
4. Fail the partitions that are on one of the old disks: mdadm /dev/md0 --fail /dev/sde1 and mdadm /dev/md1 --fail /dev/sde2
I could now either (scenario A: 3 active devices) uninstall this old disk, install the new disk and partition/--add, or (scenario B) if I've gone to 4 active devices above I could in fact repeat step 4 above for the other old drive so that I can uninstall them both at the same time, then install the second new drive. This is described in more detail below.
A.5. Find out what /dev/sde's serial number is by means of hdparm -i. Shut down. Uninstall /dev/sde, making doubly sure that it's the correct serial number. Install the second new drive.
A.6. Boot, partition the new device as above.
A.7. Add the new partitions to the md sets (mdadm --add).
A.8. Fail the partitions that reside on the disk that I want to be the spare, thereby forcing a resync onto the new partitions. I.e. mdadm /dev/md0 --fail /dev/sdb2 (assuming persistent device naming across reboots) and mdadm /dev/md1 --fail /dev/sdb3 . This fails my constraint of wanting to have full RAID redundancy at all times, at least until the resync completes. Wait for completion.
A.9. Remove and re-add the failed partitions so that they become spares again.
B.5. Fail the partitions that are on the other old disk: mdadm /dev/md0 --fail /dev/sdf1 and mdadm /dev/md1 --fail /dev/sdf2
B.6. Shut down and uninstall both old drives. No need to bother with serial numbers: I can recognise the disks by their type (the other disks in the system are from a different manufacturer). Install the other new disk.
B.7. Boot, partition the new device as above.
B.8. Add the new partitions to the md sets (mdadm --add). This will trigger a resync since the number of active devices is 4. Wait for completion.
B.9. Fail the partitions that reside on the disk that I want to be the spare.
B.10. Reduce the number of active devices to 2.
B.11. Re-add the spare partitions.
I would be most grateful for any comments or pointers to wikis etc.
Many thanks (smartctl output below).
Jan
root@zotac:~# smartctl -a /dev/sdb
smartctl 5.40 2010-03-16 r3077 [x86_64-unknown-linux-gnu] (local build)
Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net
=== START OF INFORMATION SECTION ===
Model Family: Western Digital Caviar Green family
Device Model: WDC WD20EADS-00R6B0
Serial Number: WD-WCAVY1722132
Firmware Version: 01.00A01
User Capacity: 2,000,398,934,016 bytes
Device is: In smartctl database [for details use: -P show]
ATA Version is: 8
ATA Standard is: Exact ATA specification draft version not indicated
Local Time is: Wed Jan 18 17:27:03 2012 CET
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
General SMART Values:
Offline data collection status: (0x84) Offline data collection activity
was suspended by an interrupting command from host.
Auto Offline Data Collection: Enabled.
Self-test execution status: ( 0) The previous self-test routine completed
without error or no self-test has ever
been run.
Total time to complete Offline
data collection: (41580) seconds.
Offline data collection
capabilities: (0x7b) SMART execute Offline immediate.
Auto Offline data collection on/off support.
Suspend Offline collection upon new
command.
Offline surface scan supported.
Self-test supported.
Conveyance Self-test supported.
Selective Self-test supported.
SMART capabilities: (0x0003) Saves SMART data before entering
power-saving mode.
Supports SMART auto save timer.
Error logging capability: (0x01) Error logging supported.
General Purpose Logging supported.
Short self-test routine
recommended polling time: ( 2) minutes.
Extended self-test routine
recommended polling time: ( 255) minutes.
Conveyance self-test routine
recommended polling time: ( 5) minutes.
SCT capabilities: (0x303f) SCT Status supported.
SCT Error Recovery Control supported.
SCT Feature Control supported.
SCT Data Table supported.
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 0x002f 200 200 051 Pre-fail Always - 0
3 Spin_Up_Time 0x0027 147 142 021 Pre-fail Always - 9641
4 Start_Stop_Count 0x0032 100 100 000 Old_age Always - 502
5 Reallocated_Sector_Ct 0x0033 200 200 140 Pre-fail Always - 0
7 Seek_Error_Rate 0x002e 200 200 000 Old_age Always - 0
9 Power_On_Hours 0x0032 080 080 000 Old_age Always - 15069
10 Spin_Retry_Count 0x0032 100 100 000 Old_age Always - 0
11 Calibration_Retry_Count 0x0032 100 253 000 Old_age Always - 0
12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 92
192 Power-Off_Retract_Count 0x0032 200 200 000 Old_age Always - 42
193 Load_Cycle_Count 0x0032 199 199 000 Old_age Always - 4366
194 Temperature_Celsius 0x0022 118 100 000 Old_age Always - 34
196 Reallocated_Event_Count 0x0032 200 200 000 Old_age Always - 0
197 Current_Pending_Sector 0x0032 200 200 000 Old_age Always - 0
198 Offline_Uncorrectable 0x0030 200 200 000 Old_age Offline - 0
199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age Always - 114
200 Multi_Zone_Error_Rate 0x0008 200 198 000 Old_age Offline - 0
SMART Error Log Version: 1
No Errors Logged
SMART Self-test log structure revision number 1
Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error
# 1 Short offline Completed without error 00% 15025 -
SMART Selective self-test log data structure revision number 1
SPAN MIN_LBA MAX_LBA CURRENT_TEST_STATUS
1 0 0 Not_testing
2 0 0 Not_testing
3 0 0 Not_testing
4 0 0 Not_testing
5 0 0 Not_testing
Selective self-test flags (0x0):
After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.
root@zotac:~# smartctl -a /dev/sdd
smartctl 5.40 2010-03-16 r3077 [x86_64-unknown-linux-gnu] (local build)
Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net
=== START OF INFORMATION SECTION ===
Model Family: Seagate Barracuda 7200.12 family
Device Model: ST3500418AS
Serial Number: 9VMK33L9
Firmware Version: CC44
User Capacity: 500,107,862,016 bytes
Device is: In smartctl database [for details use: -P show]
ATA Version is: 8
ATA Standard is: ATA-8-ACS revision 4
Local Time is: Wed Jan 18 17:27:44 2012 CET
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
General SMART Values:
Offline data collection status: (0x82) Offline data collection activity
was completed without error.
Auto Offline Data Collection: Enabled.
Self-test execution status: ( 0) The previous self-test routine completed
without error or no self-test has ever
been run.
Total time to complete Offline
data collection: ( 600) seconds.
Offline data collection
capabilities: (0x7b) SMART execute Offline immediate.
Auto Offline data collection on/off support.
Suspend Offline collection upon new
command.
Offline surface scan supported.
Self-test supported.
Conveyance Self-test supported.
Selective Self-test supported.
SMART capabilities: (0x0003) Saves SMART data before entering
power-saving mode.
Supports SMART auto save timer.
Error logging capability: (0x01) Error logging supported.
General Purpose Logging supported.
Short self-test routine
recommended polling time: ( 1) minutes.
Extended self-test routine
recommended polling time: ( 92) minutes.
Conveyance self-test routine
recommended polling time: ( 2) minutes.
SCT capabilities: (0x103f) SCT Status supported.
SCT Error Recovery Control supported.
SCT Feature Control supported.
SCT Data Table supported.
SMART Attributes Data Structure revision number: 10
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x000f 107 099 006 Pre-fail Always - 14023533
3 Spin_Up_Time 0x0003 097 097 000 Pre-fail Always - 0
4 Start_Stop_Count 0x0032 100 100 020 Old_age Always - 50
5 Reallocated_Sector_Ct 0x0033 100 100 036 Pre-fail Always - 0
7 Seek_Error_Rate 0x000f 079 060 030 Pre-fail Always - 93484948
9 Power_On_Hours 0x0032 088 088 000 Old_age Always - 10875
10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0
12 Power_Cycle_Count 0x0032 100 100 020 Old_age Always - 50
183 Runtime_Bad_Block 0x0000 100 100 000 Old_age Offline - 0
184 End-to-End_Error 0x0032 100 100 099 Old_age Always - 0
187 Reported_Uncorrect 0x0032 100 100 000 Old_age Always - 0
188 Command_Timeout 0x0032 100 098 000 Old_age Always - 87
189 High_Fly_Writes 0x003a 100 100 000 Old_age Always - 0
190 Airflow_Temperature_Cel 0x0022 068 059 045 Old_age Always - 32 (Lifetime Min/Max 30/37)
194 Temperature_Celsius 0x0022 032 041 000 Old_age Always - 32 (0 13 0 0)
195 Hardware_ECC_Recovered 0x001a 033 025 000 Old_age Always - 14023533
197 Current_Pending_Sector 0x0012 100 100 000 Old_age Always - 0
198 Offline_Uncorrectable 0x0010 100 100 000 Old_age Offline - 0
199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age Always - 0
240 Head_Flying_Hours 0x0000 100 253 000 Old_age Offline - 220718369352436
241 Total_LBAs_Written 0x0000 100 253 000 Old_age Offline - 1672825376
242 Total_LBAs_Read 0x0000 100 253 000 Old_age Offline - 3414488901
SMART Error Log Version: 1
No Errors Logged
SMART Self-test log structure revision number 1
No self-tests have been logged. [To run self-tests, use: smartctl -t]
SMART Selective self-test log data structure revision number 1
SPAN MIN_LBA MAX_LBA CURRENT_TEST_STATUS
1 0 0 Not_testing
2 0 0 Not_testing
3 0 0 Not_testing
4 0 0 Not_testing
5 0 0 Not_testing
Selective self-test flags (0x0):
After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.
root@zotac:~# smartctl -a /dev/sde
smartctl 5.40 2010-03-16 r3077 [x86_64-unknown-linux-gnu] (local build)
Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net
=== START OF INFORMATION SECTION ===
Model Family: Seagate Barracuda 7200.12 family
Device Model: ST3500418AS
Serial Number: 9VMM6EY4
Firmware Version: CC38
User Capacity: 500,107,862,016 bytes
Device is: In smartctl database [for details use: -P show]
ATA Version is: 8
ATA Standard is: ATA-8-ACS revision 4
Local Time is: Wed Jan 18 17:28:33 2012 CET
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
General SMART Values:
Offline data collection status: (0x82) Offline data collection activity
was completed without error.
Auto Offline Data Collection: Enabled.
Self-test execution status: ( 0) The previous self-test routine completed
without error or no self-test has ever
been run.
Total time to complete Offline
data collection: ( 600) seconds.
Offline data collection
capabilities: (0x7b) SMART execute Offline immediate.
Auto Offline data collection on/off support.
Suspend Offline collection upon new
command.
Offline surface scan supported.
Self-test supported.
Conveyance Self-test supported.
Selective Self-test supported.
SMART capabilities: (0x0003) Saves SMART data before entering
power-saving mode.
Supports SMART auto save timer.
Error logging capability: (0x01) Error logging supported.
General Purpose Logging supported.
Short self-test routine
recommended polling time: ( 1) minutes.
Extended self-test routine
recommended polling time: ( 85) minutes.
Conveyance self-test routine
recommended polling time: ( 2) minutes.
SCT capabilities: (0x103f) SCT Status supported.
SCT Error Recovery Control supported.
SCT Feature Control supported.
SCT Data Table supported.
SMART Attributes Data Structure revision number: 10
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x000f 118 099 006 Pre-fail Always - 193389141
3 Spin_Up_Time 0x0003 097 097 000 Pre-fail Always - 0
4 Start_Stop_Count 0x0032 100 100 020 Old_age Always - 98
5 Reallocated_Sector_Ct 0x0033 100 100 036 Pre-fail Always - 0
7 Seek_Error_Rate 0x000f 079 060 030 Pre-fail Always - 97304022
9 Power_On_Hours 0x0032 088 088 000 Old_age Always - 10875
10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0
12 Power_Cycle_Count 0x0032 100 100 020 Old_age Always - 49
183 Runtime_Bad_Block 0x0032 100 100 000 Old_age Always - 0
184 End-to-End_Error 0x0032 100 100 099 Old_age Always - 0
187 Reported_Uncorrect 0x0032 100 100 000 Old_age Always - 0
188 Command_Timeout 0x0032 100 100 000 Old_age Always - 0
189 High_Fly_Writes 0x003a 100 100 000 Old_age Always - 0
190 Airflow_Temperature_Cel 0x0022 068 054 045 Old_age Always - 32 (Lifetime Min/Max 31/37)
194 Temperature_Celsius 0x0022 032 046 000 Old_age Always - 32 (0 14 0 0)
195 Hardware_ECC_Recovered 0x001a 034 021 000 Old_age Always - 193389141
197 Current_Pending_Sector 0x0012 100 100 000 Old_age Always - 0
198 Offline_Uncorrectable 0x0010 100 100 000 Old_age Offline - 0
199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age Always - 0
240 Head_Flying_Hours 0x0000 100 253 000 Old_age Offline - 256985073199860
241 Total_LBAs_Written 0x0000 100 253 000 Old_age Offline - 1127059227
242 Total_LBAs_Read 0x0000 100 253 000 Old_age Offline - 3458581684
SMART Error Log Version: 1
No Errors Logged
SMART Self-test log structure revision number 1
No self-tests have been logged. [To run self-tests, use: smartctl -t]
SMART Selective self-test log data structure revision number 1
SPAN MIN_LBA MAX_LBA CURRENT_TEST_STATUS
1 0 0 Not_testing
2 0 0 Not_testing
3 0 0 Not_testing
4 0 0 Not_testing
5 0 0 Not_testing
Selective self-test flags (0x0):
After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.