Author Topic: Endless RAID Scan  (Read 716 times)

WeekendWarrior2019

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Endless RAID Scan
« on: December 15, 2019, 11:04:04 am »
I have a TS-XE4.0TL/R5 with four 1TB hard drives running in a RAID 10 array.  The firmware is current (v 1.72) and the unit is out of warranty.  The usable disk space is about 1800 GB and it is about 76.6% full.  The unit has been having problems for the last couple of weeks.  Boot-up can take over an hour until the green ring light around the power button stops flashing.  (Boot-up used to take only a couple of minutes).  Moreover, the unit appears to have been doing a RAID scan for the past week or so.  The specific message shown is "RAID     I15       ARRAY1 Scanning".  The LCD Message List published by BuffaloTech indicates that this means that the unit is examining the error status of RAID array 1 and that "transfer speeds are slower during the examination process."

While this has been going on, navigating the share drives is an extremely slow process, and accessing files is near-impossible.  Every command I give seems to time out.  Hence I can't save or retrieve information from my shares, nor can I empty the trashbox.  The unit has effectively been unusable for a couple of weeks now.  I connected the LAN2 cable to see whether that might help, and it didn't.  The bottleneck is clearly inside the unit.

At this point I don't really know what to do.  I would appreciate hearing suggestions.

One thought would be to turn off the RAID functionality and have the four drives function separately.  Could I do that and not affect the contents of the hard drives?  If that is the case, then maybe I could copy my files from drives 1 and 2 and resort to drives 3 and 4 as a back-up.

A variant of this would be to pull hard drives 3 and 4 in order to stop the RAID scan and copy my files to a new drive.

I have also considered buying either a new 4-disk enclosure or a used & empty TS-XE4.0CL/R5 from eBay, setting it for RAID 10, and popping my 4 drives into the unit.

However, I think the issue is with the drives, so I doubt that the last option would work.

Any thoughts would be appreciated.  Thanks so much!
« Last Edit: December 15, 2019, 05:07:52 pm by WeekendWarrior2019 »

1000001101000

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Re: Endless RAID Scan
« Reply #1 on: December 16, 2019, 06:20:09 am »
I’d guess one of the drives is starting to fail, this can manifest as extremely slow performance as the reads could be eventually succeeding after a lot of work by the drive’s error correction software.
 

WeekendWarrior2019

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Re: Endless RAID Scan
« Reply #2 on: December 16, 2019, 09:29:46 am »
Thanks.  So would you advise that I wait for the drive to fail?  I'm worried that that could take forever.  Is there a way to query the TeraStation to see which drive is having the errors, so that I can just pull the failing drive and get the RAID array rebuilt and usable again?

1000001101000

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Re: Endless RAID Scan
« Reply #3 on: December 16, 2019, 10:56:06 am »
I would definitely not wait for it to fail. Before doing anything else you should make sure your data is backed up.

If I'm correct I would expect that one of the drives should show a large number of ECC corrections and/or swapped sectors in its SMART data. I believe the firmware's web interface has a page to show this information. If not there are ways to connect via the command line and access this information but it is a bit more complicated.

If you can narrow it down to an individual drive you could try swapping that out with another of the same size. Depending on your long term plans it may be a good time to consider starting over with fresh drives since the other drives are likely just as old as the failing drive.

If you do decide to start over there are instructions on how to do that:
http://forums.buffalotech.com/index.php?topic=30419.0

If you prefer you can also replace the stock firmware with Debian Linux instead:
https://github.com/1000001101000/Debian_on_Buffalo
« Last Edit: December 16, 2019, 11:16:24 am by 1000001101000 »

WeekendWarrior2019

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Re: Endless RAID Scan
« Reply #4 on: December 16, 2019, 01:24:13 pm »
Thank you SO MUCH, this is quite helpful.

One of my drives failed a few months back so I got a Seagate drive of the same size from B&H Photo and followed the drive replacement procedure and everything went fine.

I'll try to dig deeper to see which drive is having the corrections and I will report back.

Thanks again!