Bryan Mesich wrote:

On Thu, May 14, 2009 at 06:06:51PM +0100, John Robinson wrote:

quoted

I think about 160 minutes is reasonable for 750GB, on an otherwise  
unloaded box; it's only 70MB/sec off 3 drives and on to 1 newer, faster  
drive.

I have a similar setup with 4 750G SATA drives.  The box is
failry beefy, with 8 processor cores and a PCI-E SATA controler
(3Ware 9650SE).  For an initial sync, it will take about 315
minutes to complete.

I'm not sure if this is a fair comparison, since Rainer was do a
resync.

md8 : active raid5 sdx1[4] sdw1[2] sdv1[1] sdu1[0]
      2197209600 blocks level 5, 64k chunk, algorithm 2 [4/3] [UUU_]
      [>....................]  recovery =  1.6% (12015536/732403200) finish=312.3min speed=38437K/sec

I'm probably splitting hairs at this point.

Bryan

Just to add another data point, I replaced a dead 750GB drive in 4 x 750 
md RAID5 last week and it took 145 minutes.

Resync on another 16 x 750GB md RAID6 takes around 180min.

Regards,

Richard