Re: RaiserFS via NFS
On Tuesday 20 April 2004 01:21, Markus Schabel wrote:
> Jeremy Zawodny wrote:
> > On Monday, April 19, 2004, at 03:07 PM, Markus Schabel wrote:
> >> well, i see the same problem as everybody here: i've had some
> >> corrupted reiserfs systems, and it wasn't possible to restore the
> >> data (except backups of coures ;)). We're still running reiserfs on
> >> our proxy servers (squid), but we have the phenomenon that the
> >> machines get slower and slower while squid is running, and if you
> >> stop squid and wait some time and start it again it all goes fine
> >> again. but the problem isn't squid, it seems to be reiserfs which
> >> seems to be not able get all data written to disk in time and slows
> >> the computer down. (sure this also depends on the harddisks, but we
> >> played around with hdparm and the situation was exactly the same
> >> with DMA enabled (140MB/s) and disabled (4MB/s), so it cannot be
> >> the HDD).
For what it's worth: I've had opposite experiences. At one time I had what
looked like severe filesystem corruption on my reiserfs disk. But it repaired
it without any problems. I've been using it for at least 3 or 4 years now, on
all my systems, ranging from laptops to a 0.4 TB raid5 fileserver and I am
very happy with both the speed and the reliability.
> > I'm confused. How does measuring sequential read/write performance
> > map to squid performance? Doesn't squid usually do lots of little
> > read/write ops, with lots of seeks too?
> well, the idea was to check if system performance would be influenced
> by HDD speed. sure sequential read/write is not really the best test
> for this, but i thougth we would see some changes, and since we didn't
> the idea was that the HDD isn't the bottleneck. and since the system
> behavior is better with ext3 than with reiserfs, the bottleneck may be
> the filesystem.
I think reiserfs is better than ext3 for lots of small files. Well, actually I
think reiserfs is better <period> but then again, I might be biased... ;-)
> is it possible to log HDD access (e.g. open, close, read, write, seek,
> etc. operations)?
Sure. man iostat (package sysstat)
(Or give bonnie a try if it is only for benchmarking)
Linux: Because rebooting is for adding hardware.