Roy Sigurd Karlsbakk wrote:
> > Right now the filesystem block size on linux is restricted to the
> > machine page size. Fixing this has been on the todo list for a
> > long time now, but other projects keep getting given higher priority.
> > The first thing to appear would be support for smaller block sizes,
> > not bigger ones - the problem in linux is that the kernel was really
> > not designed to provide chunks of memory larger than 1 page with any
> > reliability (i.e. there is a good chance it will fail).
> > Anyway, having said that, xfs will do larger I/O than this, files should
> > get layed out contiguous on disk, and both the read and write path will
> > end up issuing larger requests to the scsi devices.
> ok. So the fs block size really doesn't matter - is that it? I'm trying to
> set up streaming of multi-gigabyte files from a file system, and it's all
> too slow. Even with a RAID-0 with 5 drives (SCSI-3/160MBps/10k spin), I
> cannot get the speed higher than around 30 on ext2.
FYI, I've managed to get just over 30 MB/sec sustained (read; write
isn't too far off; both XFS and ext2 do well with average size files) on
a good 10K rpm U160 scsi drive (64 bit 66 MHz bus) if conditions are
right...no raid at all. With 5 drives on RAID 0 and your hardware specs,
can't imagine not getting far better than you get now. It sure sounds
like something is wrong.
D. Stimits, stimits@xxxxxxxxxx
> Do you or anyone else have some idea of when the TUX/XFS potch
> incompatibility problem will be solved? I need Tux (the in-kernel web
> server from RedHat) in this project as well...
> Roy Sigurd Karlsbakk, MCSE, MCNE, CLS, LCA
> Computers are like air conditioners.
> They stop working when you open Windows.