Gentoo Archives: gentoo-user

From: James <wireless@×××××××××××.com>
To: gentoo-user@l.g.o
Subject: [gentoo-user] Re: ceph on btrfs
Date: Thu, 23 Oct 2014 19:42:06
In Reply to: Re: [gentoo-user] ceph on btrfs by Andrew Savchenko
1 Andrew Savchenko <bircoph <at>> writes:
4 > Ceph is optimized for btrfs by design, it has no configure options
5 > to enable or disable btrfs-related stuff:
6 >
7 > No configure option => no use flag.
9 Good to know; nice script.
11 > Just use the latest (0.80.7 ATM). You may just nerame and rehash
12 > 0.80.5 ebuild (usually this works fine). Or you may stay with
13 > 0.80.5, but with fewer bug fixes.
15 So just download from, put it in distfiles and copy-edit
16 ceph-0.80.7 in my /usr/local/portage, or is there an overlay somewhere
17 I missed?
19 > If raid is supposed to be read more frequently than written to,
20 > then my favourite solution is raid-10-f2 (2 far copies, perfectly
21 > fine for 2 disks). This will give you read performance of raid-0 and
22 > robustness of raid-1. Though write i/o will be somewhat slower due
23 > to more seeks. Also it depends on workload: if you'll have a lot of
24 > independent read requests, raid-1 will be fine too. But for large read
25 > i/o from a single or few clients raid-10-f2 is the best imo.
27 Interesting. For now I'm going to stay with simple mirroring. After
28 some time I might migrate to a more agressive FS arrangement, once
29 I have a better idea of the i/o needs. With spark(RDD) on top of mesos,
30 I shooting for mostly "in-memory" usage so i/o is not very heavily
31 used. We'll just have to see how things work out.
33 Last point. I'm using openrc and not systemd, at this time; any
34 ceph issues with openrc, as I do see systemd related items with ceph.
37 > Andrew Savchenko
40 Very good advice.
41 Thanks,
42 James


Subject Author
Re: [gentoo-user] Re: ceph on btrfs Andrew Savchenko <bircoph@×××××.com>