[EMAIL PROTECTED] said: > Your finding for random reads with or without NCQ match my findings: http:// > blogs.sun.com/erickustarz/entry/ncq_performance_analysis > > Disabling NCQ looks like a very tiny win for the multi-stream read case. I > found a much bigger win, but i was doing RAID-0 instead of RAID-Z.
I didn't set out to do the with/without NCQ comparisons. Rather, my first runs of filebench and bonnie++ triggered a number of I/O errors and controller timeout/resets on several different drives, so I disabled NCQ based on bug 6587133's workaround suggestion. No more errors during subsequent testing, so we're running with NCQ disabled until a patch comes along. It was useful, however, to see what effect disabling NCQ had. I find filebench easier to use than bonnie++, mostly because filebench is automatically multithreaded, which is necessary to generate a heavy enough workload to exercise anything more than a few drives (esp. on machines like T2000's). The HTML output doesn't hurt, either. Regards, Marion _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
