CHeers for the reaction and sorry for my late response, I've been out
for business.
Trying to rebuild this RAID is definately worth it for me. The
learning experience alone already makes it worth.
I did read the wiki page and tried several steps that are on there but
it didn't seem to get me out of trouble.
I used this information from the drive, obviously didn't search for
any "hidden" settings:
" Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 36fdeb4b:c5360009:0958ad1e:17da451b
Name : TRD106:0 (local to host TRD106)
Creation Time : Fri Oct 10 12:27:27 2014
Raid Level : raid5
Raid Devices : 4
Avail Dev Size : 1948250112 (929.00 GiB 997.50 GB)
Array Size : 5844750336 (2786.99 GiB 2992.51 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : clean
Device UUID : b49e2752:d37dac6c:8764c52a:372277bd
Update Time : Sat Nov 5 14:40:33 2016
Checksum : d47a9ad4 - correct
Events : 14934
Layout : left-symmetric
Chunk Size : 64K
Device Role : Active device 0
Array State : AAAA ('A' == active, '.' == missing)"
Anybody that can give me a little extra push?
On 06/11/16 21:00, Dennis Dataopslag wrote:
> Help wanted very much!
Quick response ...
>
> My setup:
> Thecus N5550 NAS with 5 1TB drives installed.
>
> MD0: RAID 5 config of 4 drives (SD[ABCD]2)
> MD10: RAID 1 config of all 5 drives (SD..1), system generated array
> MD50: RAID 1 config of 4 drives (SD[ABCD]3), system generated array
>
> 1 drive (SDE) set as global hot spare.
>
Bit late now, but you would probably have been better with raid-6.
>
> What happened:
> This weekend I thought it might be a good idea to do a SMART test for
> the drives in my NAS.
> I started the test on 1 drive and after it ran for a while I started
> the other ones.
> While the test was running drive 3 failed. I got a message the RAID
> was degraded and started rebuilding. (My assumption is that at this
> moment the global hot spare will automatically be added to the array)
>
> I stopped the SMART tests of all drives at this moment since it seemed
> logical to me the SMART test (or the outcomes) made the drive fail.
> In stopping the tests, drive 1 also failed!!
> I let it for a little but the admin interface kept telling me it was
> degraded, did not seem to take any actions to start rebuilding.
It can't - there's no spare drive to rebuild on, and there aren't enough
drives to build a working array.
> At this point I started googling and found I should remove and reseat
> the drives. This is also what I did but nothing seemd to happen.
> The turned up as new drives in the admin interface and I re-added them
> to the array, they were added as spares.
> Even after adding them the array didn't start rebuilding.
> I checked stat in mdadm and it told me clean FAILED opposed to the
> degraded in the admin interface.
Yup. You've only got two drives of a four-drive raid 5.
Where did you google? Did you read the linux raid wiki?
https://raid.wiki.kernel.org/index.php/Linux_Raid
>
> I rebooted the NAS since it didn't seem to be doing anything I might interrupt.
> after rebooting it seemed as if the entire array had disappeared!!
> I started looking for options in MDADM and tried every "normal"option
> to rebuild the array (--assemble --scan for example)
> Unfortunately I cannot produce a complete list since I cannot find how
> to get it from the logging.
>
> Finally I mdadm --create a new array with the original 4 drives with
> all the right settings. (Got them from 1 of the original volumes)
OUCH OUCH OUCH!
Are you sure you've got the right settings? A lot of "hidden" settings
have changed their values over the years. Do you know which mdadm was
used to create the array in the first place?
> The creation worked but after creation it doesn't seem to have a valid
> partition table. This is the point where I realized I probably fucked
> it up big-time and should call in the help squad!!!
> What I think went wrong is that I re-created an array with the
> original 4 drives from before the first failure but the hot-spare was
> already added?
Nope. You've probably used a newer version of mdadm. That's assuming the
array is still all the original drives. If some of them have been
replaced you've got a still messier problem.
>
> The most important data from the array is saved in an offline backup
> luckily but I would very much like it if there is any way I could
> restore the data from the array.
>
> Is there any way I could get it back online?
You're looking at a big forensic job. I've moved the relevant page to
the archaeology area - probably a bit too soon - but you need to read
the following page
https://raid.wiki.kernel.org/index.php/Reconstruction
Especially the bit about overlays. And wait for the experts to chime in
about how to do a hexdump and work out the values you need to pass to
mdadm to get the array back. It's a lot of work and you could be looking
at a week what with the delays as you wait for replies.
I think it's recoverable. Is it worth it?
Cheers,
Wol
On Sun, Nov 6, 2016 at 10:00 PM, Dennis Dataopslag
<dennisdataopslag@xxxxxxxxx> wrote:
> Help wanted very much!
>
> My setup:
> Thecus N5550 NAS with 5 1TB drives installed.
>
> MD0: RAID 5 config of 4 drives (SD[ABCD]2)
> MD10: RAID 1 config of all 5 drives (SD..1), system generated array
> MD50: RAID 1 config of 4 drives (SD[ABCD]3), system generated array
>
> 1 drive (SDE) set as global hot spare.
>
>
> What happened:
> This weekend I thought it might be a good idea to do a SMART test for
> the drives in my NAS.
> I started the test on 1 drive and after it ran for a while I started
> the other ones.
> While the test was running drive 3 failed. I got a message the RAID
> was degraded and started rebuilding. (My assumption is that at this
> moment the global hot spare will automatically be added to the array)
>
> I stopped the SMART tests of all drives at this moment since it seemed
> logical to me the SMART test (or the outcomes) made the drive fail.
> In stopping the tests, drive 1 also failed!!
> I let it for a little but the admin interface kept telling me it was
> degraded, did not seem to take any actions to start rebuilding.
> At this point I started googling and found I should remove and reseat
> the drives. This is also what I did but nothing seemd to happen.
> The turned up as new drives in the admin interface and I re-added them
> to the array, they were added as spares.
> Even after adding them the array didn't start rebuilding.
> I checked stat in mdadm and it told me clean FAILED opposed to the
> degraded in the admin interface.
>
> I rebooted the NAS since it didn't seem to be doing anything I might interrupt.
> after rebooting it seemed as if the entire array had disappeared!!
> I started looking for options in MDADM and tried every "normal"option
> to rebuild the array (--assemble --scan for example)
> Unfortunately I cannot produce a complete list since I cannot find how
> to get it from the logging.
>
> Finally I mdadm --create a new array with the original 4 drives with
> all the right settings. (Got them from 1 of the original volumes)
> The creation worked but after creation it doesn't seem to have a valid
> partition table. This is the point where I realized I probably fucked
> it up big-time and should call in the help squad!!!
> What I think went wrong is that I re-created an array with the
> original 4 drives from before the first failure but the hot-spare was
> already added?
>
> The most important data from the array is saved in an offline backup
> luckily but I would very much like it if there is any way I could
> restore the data from the array.
>
> Is there any way I could get it back online?
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