Re: [gentoo-user] Good/better/best filesystem for large, static video library?

[Alan McKinnon]

On Tue, 25 Dec 2012 07:41:01 -0800
Mark Knecht <markknecht@×××××.com> wrote:

> Hi,
>    Merry Christmas to all.
>
>    Upgrading an external USB2 drive at home this Christmas morning to
> 1TB for more video storage space. One large partition, non-raid, files
> are around 1GB. The drive holds only static video files that get
> written once and don't change or get erased. No MythTV stuff or
> anything like that.
>
>    This disk reside on my main desktop machine and gets backed up
> every couple of days to another USB2 drive (FAT formatted
> unfortunately) which attaches to the TV.
>
>    With the previous local drive I used ext3 and have had no problems.
> I'm just wondering if there's a better choice & why.


I am *very* impressed with ZFS for this. Yes, I know, it's not really
there on Linux - I use it on FreeBSD (FreeNAS).

It has everything I've wanted in a filesystem for a long time, and all
the crap I've stuffed into my head over many years related to storage
just goes away. It doesn't go to some place I don't have to deal with
it, it just ceases to exist. Very nice.

There is no more weird partitions from the days of DOS, no PV/VG/LV to
remember the details of. There is only storage and ZFS knows what I
want to happen with each "chunk" of it. A "chunk" (my term) in this
context is a directory and everything below it.

ZFS doesn't have partitions and filesystems. It has volumes. A volume
is sort of a cross between a filesystem (you mount it and can assign
quotas to it) and a directory (you assign permissions and ownerships to
it). You can overcommit storage space and quotas - you do not get "disk
full" errors and three days of nightmares while you figure out how to
deal with this. the FS just tells you it used more than the allocated
space and keeps telling you till you get it under the limit.

mv'ing a few TB of video to a different FS to free up space is not fun
at all, but with ZFS it's like an mv on the same FS (that volume thing
again). It checksums every write and lets you know if things fail. It
has proper snapshots built in - that's proper as in copy-on-write so
they don't really take up space until you start modifying files. Your
media collection is like mine - I only add to it and seldom delete, so
I have months of snapshots that consume about 1% extras space. Dale's
rm problem cannot happen to me anymore hehehehe ;-)

In summary, it does everything I want and does it well. It can also do
other things I don't want but others might (eg de-dupe).


-- 
Alan McKinnon
alan.mckinnon@×××××.com