Denys Dmytriyenko wrote: > I've got the first exception (but not reset) in several days running in > the above configuration: > > Mar 3 19:09:04 [kernel] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0 > Mar 3 19:09:04 [kernel] ata1.00: irq_stat 0x00020002, device error via D2H FIS > Mar 3 19:09:04 [kernel] ata1.00: cmd ef/42:fe:00:00:00/00:00:00:00:00/40 tag 0 cdb 0x0 data 0 > Mar 3 19:09:04 [kernel] res 51/04:fe:00:00:00/00:00:00:00:00/40 Emask 0x1 (device error) > Mar 3 19:09:04 [kernel] ata1.00: configured for UDMA/100 > Mar 3 19:09:04 [kernel] ata1: EH complete > Mar 3 19:09:04 [kernel] sd 0:0:0:0: [sda] 976773168 512-byte hardware sectors (500108 MB) > Mar 3 19:09:04 [kernel] sd 0:0:0:0: [sda] Write Protect is off > Mar 3 19:09:04 [kernel] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00 > Mar 3 19:09:04 [kernel] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA > > Is it something I should be worried about? That's the drive rejecting acoustic setting command probably because the drive doesn't support it. Nothing to worry about. More recent kernels won't whine about those anymore. >>> As one of the Gurus on this list, can you suggest any tweaks/settings >>> to try out to improve/resolve my 17 MB/s write speed limit? >> How did you test? W/ dd? hdparm? > > # hdparm -t /dev/sda > > /dev/sda: > Timing buffered disk reads: 170 MB in 3.03 seconds = 56.16 MB/sec This doesn't look too bad. > # dd if=/dev/zero of=file bs=100M count=20 > 20+0 records in > 20+0 records out > 2097152000 bytes (2.1 GB) copied, 117.053 s, 17.9 MB/s > > # dd if=file of=file1 bs=100M count=20 > 20+0 records in > 20+0 records out > 2097152000 bytes (2.1 GB) copied, 161.721 s, 13.0 MB/s Write seems awfully sluggish. Does turning off NCQ help? You can turn off NCQ by echoing 1 to /sys/block/sdX/device/queue_depth. Also, which kernel is this test result from? > # dd if=file of=/dev/null bs=100M count=20 > 20+0 records in > 20+0 records out > 2097152000 bytes (2.1 GB) copied, 34.6141 s, 60.6 MB/s Read looks okay. > A similar drive in an ICH7 box shows more consistent results: > > # hdparm -t /dev/sda > > /dev/sda: > Timing buffered disk reads: 182 MB in 3.01 seconds = 60.48 MB/sec > > # dd if=/dev/zero of=file bs=100M count=100 > 100+0 records in > 100+0 records out > 10485760000 bytes (10 GB) copied, 242.908 s, 43.2 MB/s > > # dd if=file of=/dev/null bs=100M count=100 > 100+0 records in > 100+0 records out > 10485760000 bytes (10 GB) copied, 211.132 s, 49.7 MB/s Hmmm... indeed. Same kernel version? Can you post "hdparm -I" results of both drives? -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
