Gentoo Archives: gentoo-user

From: Marc Joliet <marcec@×××.de>
To: gentoo-user@l.g.o
Subject: [gentoo-user] Portage metadata cache backend: sqlite or not?
Date: Tue, 12 Aug 2014 18:10:43
Message-Id: 20140812201025.51c97196@marcec
1 Hi list
3 For the longest time I've had portage configured to use the sqlite metadata
4 cache backend as per an old HOWTO [0], however, I thought that it would be a
5 good idea to revisit that decision.
7 Now apparently, this was supposed to speed up portage, although even that
8 depends. For instance, [0] says that the metadata_overlay backend is faster on
9 fast storage; since all of portage is on an SSD, that ought to be the case for
10 me. However, [0] is pretty outdated, so I don't really know, and don't have any
11 comparison.
13 In addition to that, I don't explicitly make use of the sqlite metadata cache,
14 that is, I don't (consciously) use any software that accesses those DBs, except
15 for eix (except for overlays, where one would need to run "emerge --regen"
16 first, which is *ssssslllllloooowwwww*), which can make use of them if
17 CACHE_METHOD is set appropriately; this speeds up eix-update considerably.
19 Does anybody here have experience with this, or a recommendation? I tried
20 switching to the default cache method temporarily to see how things perform,
21 and "emerge @world -uDNva" slowed down by about 30 seconds, so preliminary
22 results point to sticking with sqlite (although it could at least partly be a
23 btrfs performance regression in Linux 3.15, since there have been several reports of
24 those, and several fixes slated for 3.16). Anyway, I'm also unsure of unintended
25 consequences, or other settings I might have to change, too.
27 Also, does anybody have any performance data and/or experience on using btrfs
28 with compression in this context?
30 [0]
32 Greetings,
33 --
34 Marc Joliet
35 --
36 "People who think they know everything really annoy those of us who know we
37 don't" - Bjarne Stroustrup


File name MIME type
signature.asc application/pgp-signature


Subject Author
[gentoo-user] Re: Portage metadata cache backend: sqlite or not? James <wireless@×××××××××××.com>
Re: [gentoo-user] Portage metadata cache backend: sqlite or not? Nilesh Govindrajan <me@××××××××.com>