From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Liontooth Subject: Raid0 rebuild slows to a crawl Date: Fri, 13 Jan 2012 13:31:17 +0530 Message-ID: <4F0FE4CD.3070703@cogweb.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids I'm trying to use a WD3200AAKX-001CA0 drive in a raid1 configuration (Debian squeeze mdadm 3.1.4-1+8efb9d1), but adding it is unusably slow: # cat /proc/mdstat Personalities : [raid1] md1 : active raid1 sdb3[2] sda3[1] 73015360 blocks [2/1] [_U] [>....................] recovery = 0.0% (28928/73015360) finish=2521.6min speed=482K/sec dmesg shows no errors: md: recovery of RAID array md0 md: minimum _guaranteed_ speed: 1000 KB/sec/disk. md: using maximum available idle IO bandwidth (but not more than 200000 KB/sec) for recovery. The drive itself doesn't seem to have a problem, though it's not particularly fast: # hdparm -tT /dev/sdb /dev/sdb: Timing cached reads: 11220 MB in 2.00 seconds = 5614.03 MB/sec Timing buffered disk reads: 174 MB in 6.44 seconds = 27.01 MB/sec # smartctl -a /dev/sdb 5 Reallocated_Sector_Ct 0x0033 133 133 140 Pre-fail Always FAILING_NOW 1265 # hdparm -i /dev/sdb /dev/sdb: Model=WDC WD3200AAKX-001CA0, FwRev=15.01H15, SerialNo=WD-WCAYUEJ66523 Config={ HardSect NotMFM HdSw>15uSec SpinMotCtl Fixed DTR>5Mbs FmtGapReq } RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=50 BuffType=unknown, BuffSize=16384kB, MaxMultSect=16, MultSect=off CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=625142448 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120} PIO modes: pio0 pio3 pio4 DMA modes: mdma0 mdma1 mdma2 UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6 AdvancedPM=no WriteCache=enabled Drive conforms to: Unspecified: ATA/ATAPI-1,2,3,4,5,6,7 * signifies the current active mode Is this a known problem? Only see it with this WD drive. Cheers, Dave