On Fri, Oct 6, 2017 at 10:12 AM, Grant Edwards
wrote:
> On 2017-10-06, Rich Freeman wrote:
>
>> 2. Xfs: If you absolutely have to mess with a filesystem (especially
>> for multimedia) this isn't a bad alternative. You won't be able to
>> shrink it, but for the most part it behaves a lot like ext4.
>
> This was probably 10ish years ago, but I switched my multimedia
> filesystems from ext* to xfs because deleting a large file (several
> GB) on an ext filesystem would basically lock up my machine for tens
> of seconds. The seemed to be a known problem in the MythTv world and
> the standard solution was to use xfs instead. Sure enough, deleting
> large files on xfs didn't cause problems.
>
> * It was probably ext3 back then, so it's possible none of this
> applies to ext4.
>
Oh, that definitely impacts ext4 in the same way, but it doesn't
change my recommendation. In normal use it really doesn't have that
much impact.
The poster wasn't asking for a recommendation for mythtv storage
specifically. I believe that back when I was running mythtv I still
used ext4 because the deletion issue wasn't actually that large in
impact in practice, but I did modify the sources to increase the
buffer sizes (otherwise I'd sometimes lose frames whether I was
deleting stuff or otherwise, as linux io queuing still has a lot of
room to improve even with ionice).
If you do have a situation where you do a lot of large file deletions
then I'd definitely consider that a reason to steer away from ext4
specifically. Xfs does handle this fine. I'm not sure about zfs or
the other options - I suspect some will work and some won't. Again,
zfs isn't really something I'd just use "by default."
Really to get more specific you'd need to know exactly how the system
will be used, and how willing to deal with issues the admin is. There
is a lot to be said for "just works."
--
Rich
