Date: Mon, 04 Apr 2011 10:48:44 +0300 From: Alexander Motin <mav@FreeBSD.org> To: lev@FreeBSD.org Cc: freebsd-hardware@freebsd.org Subject: Re: Advanced disk format at WD20EARS: what should "camcontrol identify" show? Message-ID: <4D9977DC.5070001@FreeBSD.org> In-Reply-To: <22830765.20110404101040@serebryakov.spb.ru> References: <22830765.20110404101040@serebryakov.spb.ru>
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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
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