[Cross-posting to ldoms-discuss] We are occasionally seeing massive time-to-completions for I/O requests on ZFS file systems on a Sun T5220 attached to a Sun StorageTek 2540 and a Sun J4200, and using a SSD drive as a ZIL device. Primary access to this system is via NFS, and with NFS COMMITs blocking until the request has been sent to disk, performance has been deplorable. The NFS server is a LDOM domain on the T5220.
To give an idea of how bad the situation is, iotop from the DTrace Toolkit occasionally reports single I/O requests to 15k RPM FC disks that take more than 60 seconds to complete, and even requests to a SSD drive that take over 10 seconds to complete. It's not uncommon to open a small text file using vim (or similar editor) and nothing to pop up for 10-30 seconds. Browsing the web becomes a chore, as the browser locks up for a few seconds after doing anything. I have a full write-up of the situation at http://www.cs.clemson.edu/~duckwos/zfs-performance/. Any thoughts or comments are welcome. -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
