Yes, we experienced some similar slowness on our ZFS-based lustre FS too. More details here:
http://lists.lustre.org/pipermail/lustre-discuss-lustre.org/2017-April/014390.html This also affects git repos quite a bit. The fix suggested by Andreas in that thread worked fairly well and we continue to use it. The same hardware in that thread is now running 2.10. I've quite anxious to test 2.11 and DoM but we haven't had the chance to do that yet. I'm hopeful that will improve our small file IO. -----Original Message----- From: lustre-discuss <[email protected]> on behalf of Hans Henrik Happe <[email protected]> Date: Tuesday, May 8, 2018 at 7:57 AM To: "[email protected]" <[email protected]> Subject: [lustre-discuss] Synchronous writes on a loaded ZFS OST Hi, We had some users experiencing slow vim (the editor) updates on our Lustre homedirs. Turns out vim is doing some fsyncs that does not play well with a loaded ZFS OST. We tried testing with ioping, which does synced writes (like dd with conv=fdatasync). When an OST is loaded (i.e. scrubbing) the ioping time is multiple seconds (5-10). Without load we get 100-300ms, which still is far from what a ZFS fs can deliver. To test if a ZFS fs also would be affected we created a test fs on the OST pool and ran ioping*. With or without a scrub running, the ping times averaged at around 40ms. Has anyone else experienced this? Can it be helped? Cheers, Hans Henrik * Used -WWW because ioping -W runs on an unlinked file and ZFS will not sync those to disk. _______________________________________________ lustre-discuss mailing list [email protected] http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org _______________________________________________ lustre-discuss mailing list [email protected] http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
