So, does btrfs check lowmem take days? weeks?

[Marc MERLIN <marc@merlins.org>]

Regular btrfs check --repair has a nice progress option. It wasn't
perfect, but it showed something.

But then it also takes all your memory quicker than the linux kernel can
defend itself and reliably completely kills my 32GB server quicker than
it can OOM anything.

lowmem repair seems to be going still, but it's been days and -p seems
to do absolutely nothing.

My filesystem is "only" 10TB or so, albeit with a lot of files.

2 things that come to mind
1) can lowmem have some progress working so that I know if I'm looking
at days, weeks, or even months before it will be done?

2) non lowmem is more efficient obviously when it doesn't completely
crash your machine, but could lowmem be given an amount of memory to use
for caching, or maybe use some heuristics based on RAM free so that it's
not so excrutiatingly slow?

Thanks,
Marc
-- 
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Microsoft is to operating systems ....
                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/                       | PGP 7F55D5F27AAF9D08