Guang, Try to play around with the following conf attributes specially filestore_max_inline_xattr_size and filestore_max_inline_xattrs
// Use omap for xattrs for attrs over // filestore_max_inline_xattr_size or OPTION(filestore_max_inline_xattr_size, OPT_U32, 0) //Override OPTION(filestore_max_inline_xattr_size_xfs, OPT_U32, 65536) OPTION(filestore_max_inline_xattr_size_btrfs, OPT_U32, 2048) OPTION(filestore_max_inline_xattr_size_other, OPT_U32, 512) // for more than filestore_max_inline_xattrs attrs OPTION(filestore_max_inline_xattrs, OPT_U32, 0) //Override OPTION(filestore_max_inline_xattrs_xfs, OPT_U32, 10) OPTION(filestore_max_inline_xattrs_btrfs, OPT_U32, 10) OPTION(filestore_max_inline_xattrs_other, OPT_U32, 2) I think the behavior for XFS is if the xttrs are more than 10, it will use OMAP. Thanks & Regards Somnath -----Original Message----- From: ceph-users [mailto:ceph-users-boun...@lists.ceph.com] On Behalf Of GuangYang Sent: Tuesday, June 16, 2015 11:31 AM To: ceph-de...@vger.kernel.org; ceph-users@lists.ceph.com Subject: [ceph-users] xattrs vs. omap with radosgw Hi Cephers, While looking at disk utilization on OSD, I noticed the disk was constantly busy with large number of small writes, further investigation showed that, as radosgw uses xattrs to store metadata (e.g. etag, content-type, etc.), which made the xattrs get from local to extents, which incurred extra I/O. I would like to check if anybody has experience with offloading the metadata to omap: 1> Offload everything to omap? If this is the case, should we make the inode size as 512 (instead of 2k)? 2> Partial offload the metadata to omap, e.g. only offloading the rgw specified metadata to omap. Any sharing is deeply appreciated. Thanks! Thanks, Guang _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com ________________________________ PLEASE NOTE: The information contained in this electronic mail message is intended only for the use of the designated recipient(s) named above. If the reader of this message is not the intended recipient, you are hereby notified that you have received this message in error and that any review, dissemination, distribution, or copying of this message is strictly prohibited. If you have received this communication in error, please notify the sender by telephone or e-mail (as shown above) immediately and destroy any and all copies of this message in your possession (whether hard copies or electronically stored copies). _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
