On Mon, Jul 13, 2015 at 9:49 AM, Ilya Dryomov <idryomov@xxxxxxxxx> wrote: > On Fri, Jul 10, 2015 at 9:36 PM, Jan Pekař <jan.pekar@xxxxxxxxx> wrote: >> Hi all, >> >> I think I found a bug in cephfs kernel client. >> When I create directory in cephfs and set layout to >> >> ceph.dir.layout="stripe_unit=1073741824 stripe_count=1 >> object_size=1073741824 pool=somepool" >> >> attepmts to write larger file will cause kernel hung or reboot. >> When I'm using cephfs client based on fuse, it works (but now I have some >> issues with fuse and concurrent writes too, but it is not this kind of >> problem). > > Which kernel are you running? What do you see in the dmesg when it > hangs? What is the panic splat when it crashes? How big is the > "larger" file that you are trying to write? > >> >> I think object_size and stripe_unit 1073741824 is max value, or can I set it >> higher? >> >> Default values "stripe_unit=4194304 stripe_count=1 object_size=4194304" >> works without problem on write. >> >> My goal was not to split file between osd's each 4MB of its size but save it >> in one piece. > > This is generally not a very good idea - you have to consider the > distribution of objects across PGs and how your OSDs will be utilized. Yeah. Beyond that, the OSDs will reject writes exceeding a certain size (90MB by default). I'm not sure exactly what mismatch you're running into here but I can think of several different ways a >1GB write/single object could get stuck; it's just not a good idea. -Greg _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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