> Check the I/O performance on the box. I think the "speed" indicator comes > out of calculations to determine how fast a failing drive would be > rebuilt, were you doing a rebuild instead of a check. I like using the > "dstat" tool to get that info at-a-glance > (http://dag.wieers.com/home-made/dstat/). Thank you, you're quite right! Running dtst during the check shows --dsk/sda-----dsk/sdb-----dsk/sdc-----dsk/sdd-----dsk/sde-----dsk/sdf----dsk/total- _read _writ:_read _writ:_read _writ:_read _writ:_read _writ:_read _writ:_read _writ 2954k 37k:2952k 36k:2954k 37k:2952k 35k:2955k 37k:2952k 35k: 17M 217k 62M 0 : 62M 0 : 62M 0 : 62M 0 : 61M 0 : 62M 0 : 370M 0 62M 0 : 62M 0 : 62M 0 : 62M 0 : 62M 0 : 62M 0 : 372M 0 62M 8192B: 62M 76k: 62M 76k: 62M 36k: 62M 36k: 62M 8192B: 373M 240k 47M 8192B: 47M 8192B: 47M 8192B: 47M 8192B: 47M 8192B: 47M 8192B: 283M 48k 59M 16k: 59M 16k: 59M 16k: 59M 100k: 59M 100k: 59M 16k: 353M 264k 63M 0 : 63M 0 : 63M 0 : 63M 0 : 63M 0 : 63M 0 : 378M 0 58M 0 : 58M 0 : 58M 0 : 58M 0 : 58M 0 : 58M 0 : 348M 0 57M 0 : 58M 0 : 58M 0 : 57M 0 : 58M 0 : 58M 0 : 345M 0 61M 0 : 61M 0 : 61M 0 : 61M 0 : 61M 0 : 61M 0 : 365M 0 61M 0 : 60M 0 : 60M 0 : 61M 0 : 60M 0 : 60M 0 : 363M 0 60M 16k: 60M 20k: 59M 20k: 59M 28k: 59M 28k: 60M 16k: 356M 128k Whish is 60 MB/drive, exactly as expected. On RAID-5, I could call it a "redundancy checking rate", but that doesn't correspond to the RAID-1 numbers: md0 : active raid1 sdf1[5] sde1[4] sdd1[3] sdc1[2] sdb1[1] sda1[0] 979840 blocks [6/6] [UUUUUU] [==>..................] resync = 14.3% (140480/979840) finish=0.4min speed=28096K/sec Judging from dstat, that 28 MB/s figure is a per-drive. (And I wonder why *that* is so low.) But anyway, good work on RAID-5! Multi-way RAID-1 isn't economical on large volumes of data, so it's hard to get very concerned about the speed. I *can* get > 60 MB/s per drive on 3 parallel 2-way RAID-1 checks. - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
