Gentoo Archives: gentoo-user

From: Rich Freeman <rich0@g.o>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Re: {OT?} which fs on 1.8TB partition
Date: Fri, 06 Oct 2017 17:28:18
Message-Id: CAGfcS_n6-S5ssGMZyPMgDGcMffQ5tbudF=OmsTGs5YAqam1QMw@mail.gmail.com
In Reply to: [gentoo-user] Re: {OT?} which fs on 1.8TB partition by Grant Edwards
1 On Fri, Oct 6, 2017 at 10:12 AM, Grant Edwards
2 <grant.b.edwards@×××××.com> wrote:
3 > On 2017-10-06, Rich Freeman <rich0@g.o> wrote:
4 >
5 >> 2. Xfs: If you absolutely have to mess with a filesystem (especially
6 >> for multimedia) this isn't a bad alternative. You won't be able to
7 >> shrink it, but for the most part it behaves a lot like ext4.
8 >
9 > This was probably 10ish years ago, but I switched my multimedia
10 > filesystems from ext* to xfs because deleting a large file (several
11 > GB) on an ext filesystem would basically lock up my machine for tens
12 > of seconds. The seemed to be a known problem in the MythTv world and
13 > the standard solution was to use xfs instead. Sure enough, deleting
14 > large files on xfs didn't cause problems.
15 >
16 > * It was probably ext3 back then, so it's possible none of this
17 > applies to ext4.
18 >
19
20 Oh, that definitely impacts ext4 in the same way, but it doesn't
21 change my recommendation. In normal use it really doesn't have that
22 much impact.
23
24 The poster wasn't asking for a recommendation for mythtv storage
25 specifically. I believe that back when I was running mythtv I still
26 used ext4 because the deletion issue wasn't actually that large in
27 impact in practice, but I did modify the sources to increase the
28 buffer sizes (otherwise I'd sometimes lose frames whether I was
29 deleting stuff or otherwise, as linux io queuing still has a lot of
30 room to improve even with ionice).
31
32 If you do have a situation where you do a lot of large file deletions
33 then I'd definitely consider that a reason to steer away from ext4
34 specifically. Xfs does handle this fine. I'm not sure about zfs or
35 the other options - I suspect some will work and some won't. Again,
36 zfs isn't really something I'd just use "by default."
37
38 Really to get more specific you'd need to know exactly how the system
39 will be used, and how willing to deal with issues the admin is. There
40 is a lot to be said for "just works."
41
42 --
43 Rich