Gentoo Archives: gentoo-user

From: covici@××××××××××.com
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] boot problems
Date: Fri, 16 May 2014 12:57:07
Message-Id: 30699.1400244893@ccs.covici.com
In Reply to: Re: [gentoo-user] boot problems by "Stefan G. Weichinger"
1 Stefan G. Weichinger <lists@×××××.at> wrote:
2
3 > Am 16.05.2014 14:03, schrieb Neil Bothwick:
4 > > On Fri, 16 May 2014 07:14:27 -0400, covici@××××××××××.com wrote:
5 > >
6 > >> So far, I have liked lvm, what's the advantage of btrfs over
7 > >> lvm?
8 > >
9 > > I have only looked at btrfs, with a consideration for switching
10 > > from ZFS, but it seems to offer the same advantages as ZFS. That
11 > > is, it makes things even easier than LVM does. with LVM you can
12 > > easily resize volumes and the filesystems on them, but it is still
13 > > two or three steps, more if you add RAID into the equation. The
14 > > modern filesystems do it all at once. If you need a bigger var, you
15 > > just tell it so. And it is exactly the same process for shrinking a
16 > > volume, something that can be tricky with LVM because of the need
17 > > to handle volume and filesystem separately.
18 >
19 > btrfs and zfs are removing the various layers we all had to deal with:
20 >
21 > partitions, logical volumes, raid-arrays, filesystems, and then
22 > snapshots etc.
23 >
24 > With these modern filesystems you are able to basically say:
25 >
26 > "I have these physical devices/disks, create me a pool of storage with
27 > these properties" and then just use that pool in a flexible and
28 > dynamic way.
29 >
30 > Your disk based storage is then usable in a way RAM is, you add it and
31 > it is available and you can then use it where you like it.
32 >
33 > No (or let's say "much less" ...) fixed and hard barriers like
34 > partition sizes, if you need space for /var, use it ... if you want to
35 > set quotas on /home, just set them for the subvolume, if you add
36 > another pair of harddisks, tell btrfs to redistribute redundancy
37 > information ("re-balance").
38 >
39 > (I see that Alan right now answered basically the same ;-) ).
40 >
41 > You get checksums for your blocks and the possibility to repair rotted
42 > blocks ... you get snapshots within the filesystem, no more slow
43 > rsnapshot-crontabs ...
44 >
45 > I used zfs-fuse back then and learned about the concepts, and it blew
46 > my mind already years ago ;-)
47 >
48 > zfs on linux ... it works fine for me on one server, but I never
49 > really wanted it on my main machines (desktop and laptops) although I
50 > once even wrote some "how to use zfs on your fully encrypted laptop"
51 > for a magazine. It always feels like "suboptimal because it is not in
52 > the kernel" to me (think licensing issues here).
53 >
54 > btrfs is officially in the kernel, still marked "experimental" because
55 > it is in active development, after all I read over the last days it
56 > should be quite stable to use if you don't run very complex setups or
57 > so ... and doing regular backups should be usual for the people in
58 > this list, I assume? Distros like SLES come with btrfs as default fs
59 > (soon).
60 >
61 > I migrated ~3 machines to btrfs in the last days and I really love
62 > getting rid of all the partitions and raids that grew over the years
63 > ... for now it is cleaned up and flexible and so far solid.
64 >
65 > btrfs and zfs have different concepts for various aspects, but
66 > basically the same goals. I definitely recommend to get in touch with
67 > this generation of filesystems.
68
69 Thanks much for that explanation.
70
71 So where do I find some documentation for btrfs and its user space tools?
72 --
73 Your life is like a penny. You're going to lose it. The question is:
74 How do
75 you spend it?
76
77 John Covici
78 covici@××××××××××.com

Replies

Subject Author
Re: [gentoo-user] boot problems "Stefan G. Weichinger" <lists@×××××.at>