On 03/05/2020 18:55, Caveman Al Toraboran wrote:
On Sunday, May 3, 2020 1:23 PM, Wols Lists <antli...@youngman.org.uk> wrote:
For anything above raid 1, MAKE SURE your drives support SCT/ERC. For
example, Seagate Barracudas are very popular desktop drives, but I guess
maybe HALF of the emails asking for help recovering an array on the raid
list involve them dying ...
(I've got two :-( but my new system - when I get it running - has
ironwolves instead.)
that's very scary.
just to double check: are those help emails about
linux's software RAID? or is it about hardware
RAIDs?
They are about linux software raid. Hardware raid won't be any better.
the reason i ask about software vs. hardware, is
because of this wiki article [1] which seems to
suggest that mdadm handles error recovery by
waiting for up to 30 seconds (set in
/sys/block/sd*/device/timeout) after which the
device is reset.
Which if your drive does not support SCT/ERC then goes *badly* wrong.
am i missing something?
Yes ...
to me it seems that [1]
seems to suggest that linux software raid has a
reliable way to handle the issue?
Well, if the paragraph below were true, it would.
since i guess all disks support resetting well?
That's the point. THEY DON'T! That's why you need SCT/ERC ...
[1] https://en.wikipedia.org/wiki/Error_recovery_control#Software_RAID
https://raid.wiki.kernel.org/index.php/Choosing_your_hardware,_and_what_is_a_device%3F#Desktop_and_Enterprise_drives
https://raid.wiki.kernel.org/index.php/Timeout_Mismatch
Cheers,
Wol
