minh diep wrote: > On 02/28/09 06:22, Nick Jennings wrote: >> Brian J. Murrell wrote: >>> On Sat, 2009-02-28 at 02:34 +0100, Nick Jennings wrote: >>>> I've got 4 OSTs (each 2gigs in size) on one lustre file system. I >>>> dd a 4 gig file to the filesystem and after the first OST fills up, >>>> the write fails (not enough space on device): >>> Writes to do not "cascade" over to another OST when one fills up. >> >> I see. I guess I have a misunderstanding of the way striping works. >> >> If you set the stripesize=1MB, and stripecount=-1 - Then I would >> assume this means: Split each write process into 1MB chunks, stripe >> across all OSTs. By write process I mean 1 single file being written >> to disk. I've read over Chapter 25 as well but it doesn't seem to >> clarify this for me (I'm probably letting something fly over my head). >> >> >>>> I initially thought this could be solved by enabling striping, but >>>> from HowTo (which doesn't say much on the subject admittedly) I >>>> gathered striping was already enabled? >>> No. By default, stripesize == 1. In order to get a single file onto >>> multiple OSTs you will need to explicitly set a striping policy either >>> on the file you are going to write into or the directory the file is in. >> >> Then what is stripesize=-1 used for? (when specified for the >> filesystem, and not a file or a directory). Can you give me an example? > You can only setstripe on a directory, not a file. > > You could try this > 1. rm -f /mnt/testfs/testfile1 > 2. lfs setstripe -c -1 /mnt/testfs > 3. dd if=/dev/zero of=/mnt/testfs/testfile1 bs=4096 count=614400 > 4. df -h
Ok, that makes sense in itself, but I'm still confused as to what effect the stripe settings in /proc/fs/lustre/lov/ have on new files that don't have special lfs settings. Thanks, -Nick _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
