* Uneven wear on raid1 devices
@ 2016-01-25 5:29 Adam Goryachev
2016-01-25 5:40 ` Roman Mamedov
0 siblings, 1 reply; 5+ messages in thread
From: Adam Goryachev @ 2016-01-25 5:29 UTC (permalink / raw)
To: linux-raid
Hi all,
I was hoping to get some advice on why my two SSD's seem to be wearing
unevenly, when they are both in the same raid1 array.
First, the array information:
# mdadm --misc --detail /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Fri Jun 14 00:42:04 2013
Raid Level : raid1
Array Size : 499975360 (476.81 GiB 511.97 GB)
Used Dev Size : 499975360 (476.81 GiB 511.97 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Mon Jan 25 16:20:11 2016
State : active
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Name : flail:0 (local to host flail)
UUID : 81b25e43:787b0bc4:f934d006:a726aa89
Events : 1240606
Number Major Minor RaidDevice State
2 8 17 0 active sync /dev/sdb1
1 8 49 1 active sync /dev/sdd1
# smartctl -A /dev/sdb|grep Wear
177 Wear_Leveling_Count 0x0013 093 093 000 Pre-fail
Always - 248
# smartctl -A /dev/sdd|grep Wear
177 Wear_Leveling_Count 0x0013 074 074 000 Pre-fail
Always - 915
Equally, we can see a different amount of data written to each drive:
# smartctl -A /dev/sdb|grep Written
241 Total_LBAs_Written 0x0032 099 099 000 Old_age
Always - 7169916114
# smartctl -A /dev/sdd|grep Written
241 Total_LBAs_Written 0x0032 099 099 000 Old_age
Always - 24013780683
I'm stuck wondering why one drive is getting so many more writes than
the other, and is there some way to "swap" this so that the other drive
will get the heavier load over the next 12 months?
In theory, this suggests that one drive has 74% life remaining, and the
other has 93% (unless I'm reading that incorrectly...), while 74% is
still a lot, I guess I would prefer to prevent it getting too much lower
and needing replacement....
Any suggestions or advice greatly appreciated.
Full output of smartctl -x below for each drive:
# smartctl -x /dev/sdb
smartctl 5.41 2011-06-09 r3365 [i686-linux-3.2.0-4-686-pae] (local build)
Copyright (C) 2002-11 by Bruce Allen, http://smartmontools.sourceforge.net
=== START OF INFORMATION SECTION ===
Device Model: Samsung SSD 840 PRO Series
Serial Number: S1AXNSAF702689E
LU WWN Device Id: 5 002538 5a02701b8
Firmware Version: DXM06B0Q
User Capacity: 512,110,190,592 bytes [512 GB]
Sector Size: 512 bytes logical/physical
Device is: Not in smartctl database [for details use: -P showall]
ATA Version is: 8
ATA Standard is: ATA-8-ACS revision 4c
Local Time is: Mon Jan 25 16:28:01 2016 AEDT
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: (0x00) Offline data collection activity
was never started.
Auto Offline Data Collection: Disabled.
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: (53956) seconds.
Offline data collection
capabilities: (0x53) SMART execute Offline immediate.
Auto Offline data collection on/off support.
Suspend Offline collection upon new
command.
No Offline surface scan supported.
Self-test supported.
No 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: ( 35) minutes.
SCT capabilities: (0x003d) SCT Status supported.
SCT Error Recovery Control supported.
SCT Feature Control supported.
SCT Data Table supported.
SMART Attributes Data Structure revision number: 1
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAGS VALUE WORST THRESH FAIL RAW_VALUE
5 Reallocated_Sector_Ct PO--CK 100 100 010 - 0
9 Power_On_Hours -O--CK 098 098 000 - 6435
12 Power_Cycle_Count -O--CK 099 099 000 - 1
177 Wear_Leveling_Count PO--C- 093 093 000 - 248
179 Used_Rsvd_Blk_Cnt_Tot PO--C- 100 100 010 - 0
181 Program_Fail_Cnt_Total -O--CK 100 100 010 - 0
182 Erase_Fail_Count_Total -O--CK 100 100 010 - 0
183 Runtime_Bad_Block PO--C- 100 100 010 - 0
187 Reported_Uncorrect -O--CK 100 100 000 - 0
190 Airflow_Temperature_Cel -O--CK 072 060 000 - 28
195 Hardware_ECC_Recovered -O-RC- 200 200 000 - 0
199 UDMA_CRC_Error_Count -OSRCK 100 100 000 - 0
235 Unknown_Attribute -O--C- 100 100 000 - 0
241 Total_LBAs_Written -O--CK 099 099 000 - 7169972542
||||||_ K auto-keep
|||||__ C event count
||||___ R error rate
|||____ S speed/performance
||_____ O updated online
|______ P prefailure warning
General Purpose Log Directory Version 1
SMART Log Directory Version 1 [multi-sector log support]
GP/S Log at address 0x00 has 1 sectors [Log Directory]
GP/S Log at address 0x01 has 1 sectors [Summary SMART error log]
GP/S Log at address 0x02 has 1 sectors [Comprehensive SMART error log]
GP/S Log at address 0x03 has 1 sectors [Ext. Comprehensive SMART
error log]
GP/S Log at address 0x06 has 1 sectors [SMART self-test log]
GP/S Log at address 0x07 has 1 sectors [Extended self-test log]
GP/S Log at address 0x09 has 1 sectors [Selective self-test log]
GP/S Log at address 0x10 has 1 sectors [NCQ Command Error]
GP/S Log at address 0x11 has 1 sectors [SATA Phy Event Counters]
GP/S Log at address 0x30 has 1 sectors [Reserved]
GP/S Log at address 0x80 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x81 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x82 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x83 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x84 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x85 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x86 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x87 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x88 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x89 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x8a has 16 sectors [Host vendor specific log]
GP/S Log at address 0x8b has 16 sectors [Host vendor specific log]
GP/S Log at address 0x8c has 16 sectors [Host vendor specific log]
GP/S Log at address 0x8d has 16 sectors [Host vendor specific log]
GP/S Log at address 0x8e has 16 sectors [Host vendor specific log]
GP/S Log at address 0x8f has 16 sectors [Host vendor specific log]
GP/S Log at address 0x90 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x91 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x92 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x93 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x94 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x95 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x96 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x97 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x98 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x99 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x9a has 16 sectors [Host vendor specific log]
GP/S Log at address 0x9b has 16 sectors [Host vendor specific log]
GP/S Log at address 0x9c has 16 sectors [Host vendor specific log]
GP/S Log at address 0x9d has 16 sectors [Host vendor specific log]
GP/S Log at address 0x9e has 16 sectors [Host vendor specific log]
GP/S Log at address 0x9f has 16 sectors [Host vendor specific log]
GP/S Log at address 0xa0 has 16 sectors [Device vendor specific log]
SMART Extended Comprehensive Error Log Version: 1 (1 sectors)
No Errors Logged
SMART Extended Self-test Log Version: 1 (1 sectors)
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
255 0 65535 Read_scanning was never started
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.
Error unknown SCT Temperature History Format Version (3), should be 2.
SCT Error Recovery Control:
Read: Disabled
Write: Disabled
SATA Phy Event Counters (GP Log 0x11)
ID Size Value Description
0x0001 2 0 Command failed due to ICRC error
0x0002 2 0 R_ERR response for data FIS
0x0003 2 0 R_ERR response for device-to-host data FIS
0x0004 2 0 R_ERR response for host-to-device data FIS
0x0005 2 0 R_ERR response for non-data FIS
0x0006 2 0 R_ERR response for device-to-host non-data FIS
0x0007 2 0 R_ERR response for host-to-device non-data FIS
0x0008 2 0 Device-to-host non-data FIS retries
0x0009 2 11 Transition from drive PhyRdy to drive PhyNRdy
0x000a 2 11 Device-to-host register FISes sent due to a COMRESET
0x000b 2 0 CRC errors within host-to-device FIS
0x000d 2 0 Non-CRC errors within host-to-device FIS
0x000f 2 0 R_ERR response for host-to-device data FIS, CRC
0x0010 2 0 R_ERR response for host-to-device data FIS, non-CRC
0x0012 2 0 R_ERR response for host-to-device non-data FIS, CRC
0x0013 2 0 R_ERR response for host-to-device non-data FIS,
non-CRC
# smartctl -x /dev/sdd
smartctl 5.41 2011-06-09 r3365 [i686-linux-3.2.0-4-686-pae] (local build)
Copyright (C) 2002-11 by Bruce Allen, http://smartmontools.sourceforge.net
=== START OF INFORMATION SECTION ===
Device Model: Samsung SSD 840 PRO Series
Serial Number: S12SNEAD204208R
LU WWN Device Id: 5 002538 5501d20d0
Firmware Version: DXM04B0Q
User Capacity: 512,110,190,592 bytes [512 GB]
Sector Size: 512 bytes logical/physical
Device is: Not in smartctl database [for details use: -P showall]
ATA Version is: 8
ATA Standard is: ATA-8-ACS revision 4c
Local Time is: Mon Jan 25 16:26:24 2016 AEDT
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: (0x00) Offline data collection activity
was never started.
Auto Offline Data Collection: Disabled.
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: (53956) seconds.
Offline data collection
capabilities: (0x53) SMART execute Offline immediate.
Auto Offline data collection on/off support.
Suspend Offline collection upon new
command.
No Offline surface scan supported.
Self-test supported.
No 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: ( 35) minutes.
SCT capabilities: (0x003d) SCT Status supported.
SCT Error Recovery Control supported.
SCT Feature Control supported.
SCT Data Table supported.
SMART Attributes Data Structure revision number: 1
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAGS VALUE WORST THRESH FAIL RAW_VALUE
5 Reallocated_Sector_Ct PO--CK 100 100 010 - 0
9 Power_On_Hours -O--CK 095 095 000 - 23178
12 Power_Cycle_Count -O--CK 099 099 000 - 8
177 Wear_Leveling_Count PO--C- 074 074 000 - 915
179 Used_Rsvd_Blk_Cnt_Tot PO--C- 100 100 010 - 0
181 Program_Fail_Cnt_Total -O--CK 100 100 010 - 0
182 Erase_Fail_Count_Total -O--CK 100 100 010 - 0
183 Runtime_Bad_Block PO--C- 100 100 010 - 0
187 Reported_Uncorrect -O--CK 100 100 000 - 0
190 Airflow_Temperature_Cel -O--CK 073 058 000 - 27
195 Hardware_ECC_Recovered -O-RC- 200 200 000 - 0
199 UDMA_CRC_Error_Count -OSRCK 100 100 000 - 0
235 Unknown_Attribute -O--C- 099 099 000 - 6
241 Total_LBAs_Written -O--CK 099 099 000 - 24013821507
||||||_ K auto-keep
|||||__ C event count
||||___ R error rate
|||____ S speed/performance
||_____ O updated online
|______ P prefailure warning
General Purpose Log Directory Version 1
SMART Log Directory Version 1 [multi-sector log support]
GP/S Log at address 0x00 has 1 sectors [Log Directory]
GP/S Log at address 0x01 has 1 sectors [Summary SMART error log]
GP/S Log at address 0x02 has 1 sectors [Comprehensive SMART error log]
GP/S Log at address 0x03 has 1 sectors [Ext. Comprehensive SMART
error log]
GP/S Log at address 0x06 has 1 sectors [SMART self-test log]
GP/S Log at address 0x07 has 1 sectors [Extended self-test log]
GP/S Log at address 0x09 has 1 sectors [Selective self-test log]
GP/S Log at address 0x10 has 1 sectors [NCQ Command Error]
GP/S Log at address 0x11 has 1 sectors [SATA Phy Event Counters]
GP/S Log at address 0x30 has 1 sectors [Reserved]
GP/S Log at address 0x80 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x81 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x82 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x83 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x84 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x85 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x86 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x87 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x88 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x89 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x8a has 16 sectors [Host vendor specific log]
GP/S Log at address 0x8b has 16 sectors [Host vendor specific log]
GP/S Log at address 0x8c has 16 sectors [Host vendor specific log]
GP/S Log at address 0x8d has 16 sectors [Host vendor specific log]
GP/S Log at address 0x8e has 16 sectors [Host vendor specific log]
GP/S Log at address 0x8f has 16 sectors [Host vendor specific log]
GP/S Log at address 0x90 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x91 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x92 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x93 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x94 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x95 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x96 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x97 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x98 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x99 has 16 sectors [Host vendor specific log]
GP/S Log at address 0x9a has 16 sectors [Host vendor specific log]
GP/S Log at address 0x9b has 16 sectors [Host vendor specific log]
GP/S Log at address 0x9c has 16 sectors [Host vendor specific log]
GP/S Log at address 0x9d has 16 sectors [Host vendor specific log]
GP/S Log at address 0x9e has 16 sectors [Host vendor specific log]
GP/S Log at address 0x9f has 16 sectors [Host vendor specific log]
GP/S Log at address 0xa0 has 16 sectors [Device vendor specific log]
SMART Extended Comprehensive Error Log Version: 1 (1 sectors)
No Errors Logged
SMART Extended Self-test Log Version: 1 (1 sectors)
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
255 0 65535 Read_scanning was never started
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.
Error unknown SCT Temperature History Format Version (3), should be 2.
SCT Error Recovery Control:
Read: Disabled
Write: Disabled
SATA Phy Event Counters (GP Log 0x11)
ID Size Value Description
0x0001 2 0 Command failed due to ICRC error
0x0002 2 0 R_ERR response for data FIS
0x0003 2 0 R_ERR response for device-to-host data FIS
0x0004 2 0 R_ERR response for host-to-device data FIS
0x0005 2 0 R_ERR response for non-data FIS
0x0006 2 0 R_ERR response for device-to-host non-data FIS
0x0007 2 0 R_ERR response for host-to-device non-data FIS
0x0008 2 0 Device-to-host non-data FIS retries
0x0009 2 11 Transition from drive PhyRdy to drive PhyNRdy
0x000a 2 11 Device-to-host register FISes sent due to a COMRESET
0x000b 2 0 CRC errors within host-to-device FIS
0x000d 2 0 Non-CRC errors within host-to-device FIS
0x000f 2 0 R_ERR response for host-to-device data FIS, CRC
0x0010 2 0 R_ERR response for host-to-device data FIS, non-CRC
0x0012 2 0 R_ERR response for host-to-device non-data FIS, CRC
0x0013 2 0 R_ERR response for host-to-device non-data FIS,
non-CRC
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Uneven wear on raid1 devices
2016-01-25 5:29 Uneven wear on raid1 devices Adam Goryachev
@ 2016-01-25 5:40 ` Roman Mamedov
2016-01-25 18:00 ` Phil Turmel
2016-01-27 0:05 ` Adam Goryachev
0 siblings, 2 replies; 5+ messages in thread
From: Roman Mamedov @ 2016-01-25 5:40 UTC (permalink / raw)
To: Adam Goryachev; +Cc: linux-raid
[-- Attachment #1: Type: text/plain, Size: 577 bytes --]
On Mon, 25 Jan 2016 16:29:02 +1100
Adam Goryachev <adam@websitemanagers.com.au> wrote:
> 9 Power_On_Hours -O--CK 098 098 000 - 6435
> 9 Power_On_Hours -O--CK 095 095 000 - 23178
2nd drive has almost 4x as much power-on time than the first one. My guess
would be that it accumulated all that write usage back before you put it into
this RAID1.
If you want to ensure the RAID1 usage is even, record the SMART data you have
now, and compare to the readings you will have a month later.
--
With respect,
Roman
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 181 bytes --]
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Uneven wear on raid1 devices
2016-01-25 5:40 ` Roman Mamedov
@ 2016-01-25 18:00 ` Phil Turmel
2016-01-27 0:18 ` Adam Goryachev
2016-01-27 0:05 ` Adam Goryachev
1 sibling, 1 reply; 5+ messages in thread
From: Phil Turmel @ 2016-01-25 18:00 UTC (permalink / raw)
To: Roman Mamedov, Adam Goryachev; +Cc: linux-raid
On 01/25/2016 12:40 AM, Roman Mamedov wrote:
> On Mon, 25 Jan 2016 16:29:02 +1100
> Adam Goryachev <adam@websitemanagers.com.au> wrote:
>
>> 9 Power_On_Hours -O--CK 098 098 000 - 6435
>
>> 9 Power_On_Hours -O--CK 095 095 000 - 23178
>
> 2nd drive has almost 4x as much power-on time than the first one. My guess
> would be that it accumulated all that write usage back before you put it into
> this RAID1.
Or you are doing "repair" scrubs when you should be doing "check"
scrubs. Any operation that requires resynchronization will read from
the first mirror and write to the others.
> If you want to ensure the RAID1 usage is even, record the SMART data you have
> now, and compare to the readings you will have a month later.
By the way, your devices show scterc disabled. That's bad. You should
definitely use boot scripts or udev rules to enable it.
Has sdd been getting bumped out of the array lately, and resyncing when
you put it back?
Phil
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Uneven wear on raid1 devices
2016-01-25 5:40 ` Roman Mamedov
2016-01-25 18:00 ` Phil Turmel
@ 2016-01-27 0:05 ` Adam Goryachev
1 sibling, 0 replies; 5+ messages in thread
From: Adam Goryachev @ 2016-01-27 0:05 UTC (permalink / raw)
To: Roman Mamedov; +Cc: linux-raid
On 25/01/16 16:40, Roman Mamedov wrote:
> On Mon, 25 Jan 2016 16:29:02 +1100
> Adam Goryachev <adam@websitemanagers.com.au> wrote:
>
>> 9 Power_On_Hours -O--CK 098 098 000 - 6435
>> 9 Power_On_Hours -O--CK 095 095 000 - 23178
> 2nd drive has almost 4x as much power-on time than the first one. My guess
> would be that it accumulated all that write usage back before you put it into
> this RAID1.
>
> If you want to ensure the RAID1 usage is even, record the SMART data you have
> now, and compare to the readings you will have a month later.
Hmmm, oops, I should have looked at that. Now of course, I realise one
drive was replaced under warranty when it failed around 6 months ago
(well, the value says just under 9 months actually), and that would
explain the difference in wear and power on hours (aside from the
initial full sync when the new device was first installed).
So, 2.5 years old, and 74% life remaining, and 9 months with 93% life
remaining.
Sounds good to me, I should expect these to last at least the 5 years I
was hoping for, and probably before that happens I will want to upgrade
them to increase capacity anyway.
Thanks for your help
Regards,
Adam
--
Adam Goryachev Website Managers www.websitemanagers.com.au
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Uneven wear on raid1 devices
2016-01-25 18:00 ` Phil Turmel
@ 2016-01-27 0:18 ` Adam Goryachev
0 siblings, 0 replies; 5+ messages in thread
From: Adam Goryachev @ 2016-01-27 0:18 UTC (permalink / raw)
To: Phil Turmel, Roman Mamedov; +Cc: linux-raid
On 26/01/16 05:00, Phil Turmel wrote:
> On 01/25/2016 12:40 AM, Roman Mamedov wrote:
>> On Mon, 25 Jan 2016 16:29:02 +1100
>> Adam Goryachev <adam@websitemanagers.com.au> wrote:
>>
>>> 9 Power_On_Hours -O--CK 098 098 000 - 6435
>>> 9 Power_On_Hours -O--CK 095 095 000 - 23178
>> 2nd drive has almost 4x as much power-on time than the first one. My guess
>> would be that it accumulated all that write usage back before you put it into
>> this RAID1.
> Or you are doing "repair" scrubs when you should be doing "check"
> scrubs. Any operation that requires resynchronization will read from
> the first mirror and write to the others.
No, definitely not doing a repair scrub, so sounds like the issue was
just the power on hours problem.
>> If you want to ensure the RAID1 usage is even, record the SMART data you have
>> now, and compare to the readings you will have a month later.
> By the way, your devices show scterc disabled. That's bad. You should
> definitely use boot scripts or udev rules to enable it.
Ooops, thank you for catching this, well understood how bad it is, I
just assumed (badly) that I was using decent drives (I always used the
WD enterprise black), and clearly forgot to check for this on an SSD.
I've enabled it now from /etc/rc.local, as well as fixing the scheduler
to noop on the SSD instead of cfq.
> Has sdd been getting bumped out of the array lately, and resyncing when
> you put it back?
No, but I wonder if this might have explained the drop from around 9
months ago, when I re-plugged it and it tested fine, but I asked them to
replace it anyway (which they did). So, I can't complain about it too much.
Regards,
Adam
--
Adam Goryachev Website Managers www.websitemanagers.com.au
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2016-01-27 0:18 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-01-25 5:29 Uneven wear on raid1 devices Adam Goryachev
2016-01-25 5:40 ` Roman Mamedov
2016-01-25 18:00 ` Phil Turmel
2016-01-27 0:18 ` Adam Goryachev
2016-01-27 0:05 ` Adam Goryachev
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