Hi. On 04.04.2011 09:10, Lev Serebryakov wrote:
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: ================ blob# camcontrol identify /dev/ada5 pass5:<WDC WD20EARS-00MVWB0 51.0AB51> ATA-8 SATA 2.x device pass5: 300.000MB/s transfers (SATA 2.x, UDMA6, PIO 8192bytes) protocol ATA/ATAPI-8 SATA 2.x device model WDC WD20EARS-00MVWB0 firmware revision 51.0AB51 serial number WD-WMAZA2743249 WWN 50014ee6ab72f596 cylinders 16383 heads 16 sectors/track 63 sector size logical 512, physical 512, offset 0 LBA supported 268435455 sectors LBA48 supported 3907029168 sectors PIO supported PIO4 DMA supported WDMA2 UDMA6 ================ Should "camcontrol identify" shows "physical 4096" in "sector size"? Some Alexander Motin's posts to mailing lists says "yes", but I can not find what should I think (do) if it doesn't.
Unluckily present 4K driver don't usually honor specification in part of reporting physical sector sizes. I haven't seen supporting ones myself actually. So I wouldn't trust those 512/512/0 numbers.
It is 8-STABLE (after 8.2-RELEASE) system. RAID stripes are 128KiB, and RAID is built from whole drives (no partitions), so, write requests should not be misaligned.
At least first 4K WD disks had a jumper to add offset of 63 sectors. Make sure that you don't have one set.
-- Alexander Motin _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hardware To unsubscribe, send any mail to "[email protected]"
