Run SMART long tests in parallel?

Goverp · Advocate Joined: 07 Mar 2007 Posts: 2011

I've a monthly cron job to remind me to run checkarray on my RAID setup, which also reminded me that perhaps it's sensible to run a SMART long test every so often. However, as that takes ages on a modern drive |(2 hrs for mine), I'd rather run them in parallel than sequentially. AFAIK, the test is performed in hardware, so the PCIe bus doesn't get flooded with spurious data, so I think that kicking off 5 parallel tests, one per drive, would be OK.

A second question is how frequently I should run it (and ditto for the checkarray). I've seen a recommendation for weekly short tests (not sure if that buys anything over and above just using the RAID array) and extended tests quarterly, or monthly, or twice a year.
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Zucca · Posted: Fri Apr 05, 2024 1:22 pm Post subject:

I think most people would recommend not to run short test at all, but only long tests.
For server You could run the test every week, or even every night. I have no idea how much that will wear a HDD or SSD down.

With dev-libs/libatasmart comes few tools which you can use to initiate the tests.

I once started a small project around the tools of libatasmart to challenge myself and learn awk. With it you should be able to start tests in parallel. Although I think I need to write rewrite that in ~POSIX sh or bash. It's been quite long abandoned.

However you could also do the same with simple shell commands using the cli tools from libatasmart. You won't get such nice progress display.

Note that I don't know if libatasmart could "collide" with smartmontools in certain situations.
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Goverp · Advocate Joined: 07 Mar 2007 Posts: 2011

Well, I've kicked off a full set of parallel long tests to see what happens with:

NeddySeagoon · Posted: Fri Apr 05, 2024 4:38 pm Post subject:

Goverp,

What will the SMART long test tell you that the checkarray won't?
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NeddySeagoon

Computer users fall into two groups:-
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those that have never had a hard drive fail.

Goverp · Advocate Joined: 07 Mar 2007 Posts: 2011

Neddy,

Dunno, but it doesn't tie up the PCIe bus. May also do some electronics testing, according to the SMART writeup, though that may be no more than a checkarray does.

All 5 tests successfully completed in parallel in about 2 hours; no errors logged. The PC's "I'm doing I/O" light was off the entire time (or at least, whenever I looked at it).
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Greybeard

NeddySeagoon · Posted: Fri Apr 05, 2024 7:24 pm Post subject:

Goverp,

Yep, the long test is a surface scan. Like dd'ing the whole drive to /dev/null. It stops at the first read error.
As you say, it's all internal t the drive. That makes it good for separating internal drive errors from external problems.

checkarray validates the array parity information. That has to tie up the PCIe bus.
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NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Goverp · Advocate Joined: 07 Mar 2007 Posts: 2011

NeddySeagoon · Posted: Sat Apr 06, 2024 9:58 am Post subject:

Goverp,

I raid everything except boot and maybe swap, then use LVM on top of mdadm.
device mapper (LVM) can do its own raid, its even the same kernel code, but being old and cynical, I like the conceptual simplicity (for my mind) of the separate layers.
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Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.