On 04/04/2011 08:10, Lev Serebryakov wrote:
Hello, Alexander.

     I'm replacing old WD500AAKS HDDs in my (software) RAID5 with new
WD20EARS, which are advanced format. And speed is terrible. RAID5
rebuilding shows about 8MiB/s (55MiB/s is typical speed for old AAKSes)...

   I'm affraid, that my HDD is in some strange mode with 512 byte
sectors emulation:

With such drives, everything must be 4 KiB-aligned : the RAID stripes, the partitions / slices and the file system / block size. This is the only way to get good performance.

If you just replace a non-4K drive in a RAID5 with a 4K drive, it is very likely that there would be alignment problems with that drive.

_______________________________________________
[email protected] mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-hardware
To unsubscribe, send any mail to "[email protected]"

Reply via email to