[mythtv-users] Fastest file system
brandon+myth at linuxis.us
Fri Sep 9 15:43:51 UTC 2005
On Fri, Sep 09, 2005 at 07:13:31AM -0700, Asher Schaffer wrote:
> I have heard of problems with XFS with any power outages, bad
> shutdowns, etc. I use JFS and have found it very fast (excellent
> large file deletes). I'm curious to other people's opinion of it,
> doesn't seem to get as much mention here as XFS or Reiser.
I've run XFS on 5x200GB drives in LVM with a 2GB root and 1TB /media
partition for over a year. Prior to this setup I ran XFS for 6 months
and JFS on 250GB of Raid 5 and 750GB of Raid 0 for just over a year.
I've had no corruption on any of them. I've hard rebooed the system
many dozens of times in all setups without any problems. The only
problems I've ever had were because a disk went bad and LVM choked hard,
and I lost everything.
JFS in my testing had slightly better performance (5%) than XFS but used
about 50% more CPU than XFS. I think both XFS and JFS are good choices.
I did not pick reiser for many reasons. The two major reasons were I
hated waiting 15 seconds to delete a 100+GB file/recording. JFS took
about 3 seconds, XFS is almost instant. The second reason is that I've
seen the people who write and support resier skew benchmark results to
try to make them look better and that's enough for me not trust it to be
better overall. Resier 4 is likely to be very, very good. For me, XFS
and JFS are my choices, and work perfectly well. JFS may be slightly
more stable than XFS from reports I've heard too. I don't think anyone
would be unhappy with either of these choices. Back when myth didn't
have ringbuffers for HD recordings filesystem performance made a huge
difference. I found problems with ext2, ext3, and reiser 3 when
recording 4 HD shows and watching another at the same time (Very common
for me to be doing). I also did this on a AMD 2500 which was before
a little bloatware in Myth and the 2500 would work fine for HD viewing.
If I were to build another system today, I'd pick JFS or XFS based on
which was usable during the system installer. If both were there I'd
pick JFS just "incase I did have those XFS power problems" but that's
such a small point.
It really comes down to how much do you want to perfect things. At some
point it's not worth the time. I suppose if I wanted the "perfect
setup" I'd use reiser 4 for my root fs that holds the mysql database and
system programs, jfs for things I don't want to lose as easly, and xfs
for the 100's of GB's for HD recordings. This can be a pain though, and
to me isn't worth it, so I pick XFS or JFS for everything. The
performance for most everything (but deleting) I've found is so close
it's not worth the time figuring out. -- And on top of all this, one FS
may work better on a certain brand or model of hard drive than another
setup. It's just not worth it to "figure out" unless you need ever last
IO to be perfected, and frankly it's no longer needed in a HTPC as of
about a year ago.
So, pick what's most convenient.
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