Re: RAID1 degraded

[Adam Goryachev <mailinglists@websitemanagers.com.au>]

On 04/08/15 15:51, Hans Malissa wrote:
> Thanks a lot for your help!
> Rebooting the system didn’t solve the problem, /dev/sdc is still 
> nowhere to be found.
> So I will have to replace /dev/sdc.
> I tried to learn a bit about SRC/ERC from list archives, and it seems 
> like my hard drives (1TB Seagate Barracuda’s) don’t support this option:
>
> # smartctl -l scterc /dev/sdb
> smartctl 6.0 2012-10-10 r3643 [x86_64-linux-3.7.10-1.45-desktop] (SUSE 
> RPM)
> Copyright (C) 2002-12, Bruce Allen, Christian Franke, 
> www.smartmontools.org <http://www.smartmontools.org>
>
> SCT Error Recovery Control command not supported
>
> /dev/sdc is (was) of exactly the same type, so it wouldn’t support 
> SRC/ERC either.
> This doesn’t seem to be the problem here, since the drive has just 
> disappeared.

Nope that is true, but it is always good to learn about the issue before 
it becomes the problem.

> But I will certainly take this into account when buying a replacement 
> drive. Any current recommendations about what would work best in a 
> RAID1 instead of a 1TB Seagate Barracuda?

My personal preference was WD Black drives, or else Enterprise Black, 
but they were always a lot more expensive. I think WD Red are "RAID 
Certified" these days. (Note, I mostly use SSD now rather than any brand 
HDD, so not a lot of recent experiences).

> Just to make sure I understand correctly how to replace /dev/sdc and 
> repair my RAID1, the steps to do would be:
>
>  1. Shutdown PC
>  2. Replace /dev/sdc
>  3. Restart computer
>  4. Partition the new /dev/sdc
>  5. Run # mdadm —manage /dev/md0 —add /dev/sdc1
>  6. Wait for synchronization to finish
>
> Did I get this right? Am I missing anything? Are there additional 
> steps (I am backing my data up, anyway) that I can take to maximize my 
> chance for success?

Yep, all sounds good. Just make a note of the serial number for sdb 
before you shutdown, and ensure you are removing the correct drive. The 
good thing with RAID1 is that it is difficult to really screw it up, but 
backups are *always* a good idea :)

Regards,
Adam

> Thanks a lot,
>
> Hans
>
> On Aug 3, 2015, at 10:33 PM, Adam Goryachev 
> <mailinglists@websitemanagers.com.au 
> <mailto:mailinglists@websitemanagers.com.au>> wrote:
>
>> On 04/08/15 14:16, Hans Malissa wrote:
>>> Thanks a lot for your help!
>>> smartctl yields the following information (details see below): 
>>> /dev/sdb looks ok, but /dev/sdc seems to have quite a problem. 
>>> /dev/sdc seems nonexistent, it’s not even in /dev/ anymore. The disk 
>>> is physically present, but that’s about it.
>>> The kernel logs contain a lot of information; what should I be 
>>> looking for?
>>
>> The logs should contain information on why or what happened when the 
>> disk (sdc) vanished. In your case, it does indeed look like sdc has 
>> failed, so you have a number of options depending on your preference:
>> 1) Simply reboot (including a complete power off) the machine, and 
>> see if sdc comes back. If it does, do some tests, and then add back 
>> to the array. If it survives, then carry on as normal.
>>
>> 2) If you are more cautious (and more prepared to spend the money 
>> rather than risk the data), then purchase a replacement disk, and 
>> replace sdc with the new disk. Prepare the drive/partition, and add 
>> it to the raid array.
>>
>> Please make sure you "Research SCT/ERC on this list"!!! before 
>> purchasing the replacement drive. It is far better to buy the right 
>> drive if possible.
>>
>> Regards,
>> Adam
>>
>>> Thanks a lot,
>>>
>>> Hans
>>>
>>> # smartctl -a /dev/sdb
>>> smartctl 6.0 2012-10-10 r3643 [x86_64-linux-3.7.10-1.45-desktop] 
>>> (SUSE RPM)
>>> Copyright (C) 2002-12, Bruce Allen, Christian Franke, 
>>> www.smartmontools.org <http://www.smartmontools.org>
>>>
>>> === START OF INFORMATION SECTION ===
>>> Model Family:     Seagate Barracuda 7200.14 (AF)
>>> Device Model:     ST1000DM003-1ER162
>>> Serial Number:    Z4Y6N2J3
>>> LU WWN Device Id: 5 000c50 07afe5c18
>>> Firmware Version: CC45
>>> User Capacity:    1,000,204,886,016 bytes [1.00 TB]
>>> Sector Sizes:     512 bytes logical, 4096 bytes physical
>>> Rotation Rate:    7200 rpm
>>> Device is:        In smartctl database [for details use: -P show]
>>> ATA Version is:   ACS-2, ACS-3 T13/2161-D revision 3b
>>> SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
>>> Local Time is:    Mon Aug  3 21:52:32 2015 MDT
>>>
>>> ==> WARNING: A firmware update for this drive may be available,
>>> see the following Seagate web pages:
>>> http://knowledge.seagate.com/articles/en_US/FAQ/207931en
>>> http://knowledge.seagate.com/articles/en_US/FAQ/223651en
>>>
>>> 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:                (   80) seconds.
>>> Offline data collection
>>> capabilities:                    (0x73) 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.
>>>                                         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:        ( 105) minutes.
>>> Conveyance self-test routine
>>> recommended polling time:        (   2) minutes.
>>> SCT capabilities:              (0x1085) SCT Status 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   111   100   006    Pre-fail 
>>>  Always       -       39301104
>>>   3 Spin_Up_Time            0x0003   097   097   000    Pre-fail 
>>>  Always       -       0
>>>   4 Start_Stop_Count        0x0032   100   100   020    Old_age 
>>>   Always       -       20
>>>   5 Reallocated_Sector_Ct   0x0033   100   100   010    Pre-fail 
>>>  Always       -       0
>>>   7 Seek_Error_Rate         0x000f   063   060   030    Pre-fail 
>>>  Always       -       2152462
>>>   9 Power_On_Hours          0x0032   098   098   000    Old_age 
>>>   Always       -       1872
>>>  10 Spin_Retry_Count        0x0013   100   100   097    Pre-fail 
>>>  Always       -       0
>>>  12 Power_Cycle_Count       0x0032   100   100   020    Old_age 
>>>   Always       -       20
>>> 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 0 0
>>> 189 High_Fly_Writes         0x003a   100   100   000    Old_age 
>>>   Always       -       0
>>> 190 Airflow_Temperature_Cel 0x0022   068   064   045    Old_age 
>>>   Always       -       32 (Min/Max 26/35)
>>> 191 G-Sense_Error_Rate      0x0032   100   100   000    Old_age 
>>>   Always       -       0
>>> 192 Power-Off_Retract_Count 0x0032   100   100   000    Old_age 
>>>   Always       -       0
>>> 193 Load_Cycle_Count        0x0032   093   093   000    Old_age 
>>>   Always       -       15119
>>> 194 Temperature_Celsius     0x0022   032   040   000    Old_age 
>>>   Always       -       32 (0 19 0 0 0)
>>> 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      -       662h+04m+56.474s
>>> 241 Total_LBAs_Written      0x0000   100   253   000    Old_age 
>>>   Offline      -       2212066311
>>> 242 Total_LBAs_Read         0x0000   100   253   000    Old_age 
>>>   Offline      -       4204083236
>>>
>>> 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.
>>>
>>> # smartctl -a /dev/sdc
>>> smartctl 6.0 2012-10-10 r3643 [x86_64-linux-3.7.10-1.45-desktop] 
>>> (SUSE RPM)
>>> Copyright (C) 2002-12, Bruce Allen, Christian Franke, 
>>> www.smartmontools.org
>>>
>>> Smartctl open device: /dev/sdc failed: No such device
>>>
>>> On Aug 3, 2015, at 5:48 PM, Adam Goryachev 
>>> <mailinglists@websitemanagers.com.au> wrote:
>>>
>>>> On 04/08/15 08:18, Hans Malissa wrote:
>>>>> Hi everybody,
>>>>>
>>>>> It looks like one of my disks in my RAID1 just failed:
>>>>>
>>>>> [SNIP]
>>>>>
>>>>> Are there any other tests I could run in order to figure out 
>>>>> what’s going on? It looks like I will have to replace /dev/sdc1 
>>>>> with a new hard drive. What is the correct procedure to do so 
>>>>> without loosing my data?
>>>>>
>>>> Have a look at dmesg or your system kernel logs for details.
>>>> Also, use smartctl to examine what the drive itself thinks.
>>>> Also, try to use dd to read/write the drive.
>>>>
>>>> One common scenario is that you haven't configured the timing for 
>>>> the drive correctly, and the drive is working perfectly, but didn't 
>>>> respond to the kernel quickly enough. Research SCT/ERC on this list
>>>>
>>>> Regards,
>>>> Adam
>>>> --
>>>> Adam Goryachev Website Managers www.websitemanagers.com.au
>>
>>
>> --
>> Adam Goryachev Website Managerswww.websitemanagers.com.au 
>> <http://www.websitemanagers.com.au/>
>


-- 
Adam Goryachev Website Managers www.websitemanagers.com.au
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