Gentoo Archives: gentoo-user

From: Andrew Savchenko <bircoph@×××××.com>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] ceph on btrfs
Date: Thu, 23 Oct 2014 13:49:45
Message-Id: 20141023174903.dfc6e5be9f0213c4cd884101@gmail.com
In Reply to: [gentoo-user] ceph on btrfs by James
1 Hi,
2
3 On Wed, 22 Oct 2014 20:05:48 +0000 (UTC) James wrote:
4 > Hello,
5 >
6 > So looking at the package sys-cluster/ceph, I see these flags:
7 > cryptopp debug fuse gtk +libaio libatomic +nss radosgw static-libs tcmalloc
8 > xfs zfs No specific flags for btrfs?
9
10 Ceph is optimized for btrfs by design, it has no configure options
11 to enable or disable btrfs-related stuff:
12 https://github.com/ceph/ceph/blob/master/configure.ac
13 No configure option => no use flag.
14
15 > ceph-0.67.9 is marked stable, while 0.67.10 and 0.80.5 are marked
16 > (yellow) testing and *9999 is marked (red) masked. So what version
17 > would anyone recommend, with what flags? [1]
18
19 Just use the latest (0.80.7 ATM). You may just nerame and rehash
20 0.80.5 ebuild (usually this works fine). Or you may stay with
21 0.80.5, but with fewer bug fixes.
22
23 > Ceph will be the DFS on top of a (3) node mesos+spark cluster.
24 > btrfs is being set up with 2 disks in raid 1 on each system. Btrfs
25 > seems to be keenly compatible with ceph [2].
26
27 If raid is supposed to be read more frequently than written to,
28 then my favourite solution is raid-10-f2 (2 far copies, perfectly
29 fine for 2 disks). This will give you read performance of raid-0 and
30 robustness of raid-1. Though write i/o will be somewhat slower due
31 to more seeks.
32
33 Also it depends on workload: if you'll have a lot of independent
34 read requests, raid-1 will be fine too. But for large read i/o from
35 a single or few clients raid-10-f2 is the best imo.
36
37 > Guidance and comments, warmly requested,
38 > James
39 >
40 >
41 > [1]
42 > http://ceph.com/docs/v0.78/rados/configuration/filesystem-recommendations/
43 >
44 > [2] http://ceph.com/docs/master/release-notes/#v0-80-firefly
45
46 Best regards,
47 Andrew Savchenko

Replies

Subject Author
[gentoo-user] Re: ceph on btrfs James <wireless@×××××××××××.com>