Hi, There was a recent osd journaling bug fix that is in the testing branch of git://ceph.newdream.net/git/ceph.git It should be in v0.24.2 when it is released, according to http://tracker.newdream.net/issues/666. I experienced frequent hangs on large writes until this bug was fixed. The obvious manifestation of this bug was that osds would assert like this: FAILED assert(repop_queue.front() == repop) However, I also experienced hangs during heavy writing where the osds would go idle and clients had outstanding write requests that never completed. I was never able to isolate the cause, but I haven't seen that behavior since this bug was fixed. -- Jim On Thu, 2011-01-20 at 11:22 -0700, Ajit K Jena wrote: > Dear List members, > > We have setup a CEPH testbed based on Fedora Core 14 > machines with 4 GB memory on all. We are using CEPH > version 0.24 with the components as below: > > one mds and one cmon (physically on the same machine) > two ods (ods1 and ods2) > btrfs is used > > The distributed volume is mounted on two client machines. > When we created small files (basically text files running > to hundreds of bytes) we have no issues. The files (both > the metadata and the contents) are consistently visible > on both the clients. > > The moment we try to store files of sizes 1 megabyte and > beyond the clients start hanging. The only way out is > "HARD REBOOT". > > I am very much aware that CEPH is not yet fit for live > deployment and is still undergoing rapid developments. > However, I wish to know if others have got results > better than this. > > Regards. > > --ajit > > > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
