Re: [gentoo-user] Unable to expand ext4 partition

[Mark Knecht]

If it's a WD Red Plus on the label then it's CMR and good. If it's WD
Red without the "Plus" then it's SMR and WD has said don't use them
for this purpose. It's not impossible to run the WD Red in a RAID, but
they tend to fail when resilvering. If it resilvers correctly then it
will probably be OK at least in the short term but you should consider
getting a couple of Red Plus and having them on hand if the plain WD
Red goes bad.

HTH,
Mark

On Sat, Feb 5, 2022 at 5:38 PM Julien Roy <julien@××××.ca> wrote:
>
> Thanks - the drives are new from this year, so I don't think they'll fail any time soon.
> Considering that the WD60EFAX is advertised as "RAID compatible", what's for sure is that my next drives won't be WD. CMR *or* SMR...
>
> Feb 5, 2022, 18:04 by antlists@××××××××××××.uk:
>
> Ouch. EFAX drives are the new SMR version it seems. You might have been lucky, it might have added okay.
>
> The problem with these drives, basically, is you cannot stream data to them. They'll accept so much, fill up their CMR buffers, and then stall while they do an internal re-organisation. And by the time they start responding again, the OS thinks the drive has failed ...
>
> I've just bought a Toshiba N300 8TB for £165 as my backup drive. As far as I know that's an okay drive for raid - I haven't heard any bad stories about SMR being sneaked in ... I've basically split it in 2, 3TB as a spare partition for my raid, and 5TB as backup for my 6TB (3x3) raid array.
>
> Look at creating a raid-10 from your WDs, or if you create a new raid-5 array from scratch using --assume-clean then format it, you're probably okay. Replacing SMRs with CMRs will probably work fine so if one of your WDs fail, you should be okay replacing it, so long as it's not another SMR :-) (If you do a scrub, expects loads of parity errors first time :-) but you will probably get away with it if you're careful.
>
> Cheers,
> Wol
>
>