From: Ricardo Wurmus <rekado@elephly.net>
To: Mathieu Othacehe <othacehe@gnu.org>
Cc: 51787@debbugs.gnu.org
Subject: bug#51787: Disk performance on ci.guix.gnu.org
Date: Sat, 25 Dec 2021 23:19:23 +0100 [thread overview]
Message-ID: <87wnjsjpdh.fsf@elephly.net> (raw)
In-Reply-To: <87v8zhn9m1.fsf@elephly.net>
Ricardo Wurmus <rekado@elephly.net> writes:
> Today we discovered a few more things and discussed them on IRC. Here’s
> a summary.
>
> /var/cache sits on the same storage as /gnu. We mounted the 5TB ext4
> file system that’s hosted by the SAN at /mnt_test and started copying
> over /var/cache to /mnt_test/var/cache. Transfer speed was considerably
> faster (not *great*, but reasonably fast) than the copy of
> /gnu/store/trash to the same target.
Turns out that space on the SAN is insufficient for a full copy of
/var/cache. We’ve hit ENOSPC after 4.2TB. The SAN enforces some
headroom to remain free, so it denies us full access to the 5TB slice.
Bummer.
I guess we’ll have to wait for the SAN extension some time early 2022
before we can relocate the substitutes cache.
Should we attempt to overwrite /gnu/store and rely exclusively on
substitutes from the cache?
No matter how we look at it, the huge store is a performance problem for
us. Today I had to kill ’guix gc’ after the GC lock had been held for
about 24 hours. We will keep having this problem.
--
Ricardo
next prev parent reply other threads:[~2021-12-25 22:24 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <875yrjpi1y.fsf@elephly.net>
2021-12-20 16:59 ` bug#51787: Disk performance on ci.guix.gnu.org Mathieu Othacehe
2021-12-20 17:05 ` Ricardo Wurmus
2021-12-20 21:53 ` Mathieu Othacehe
2021-12-21 17:26 ` Ricardo Wurmus
2021-12-21 17:51 ` Leo Famulari
2021-12-21 18:23 ` Mathieu Othacehe
2021-12-21 23:20 ` Bengt Richter
2021-12-22 0:27 ` Thiago Jung Bauermann via Bug reports for GNU Guix
2021-12-25 22:19 ` Ricardo Wurmus [this message]
2021-12-26 8:53 ` Mathieu Othacehe
2021-12-30 10:44 ` Ricardo Wurmus
2021-12-20 18:36 ` Bengt Richter
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