About once a year I get a SCSI parity error on one of my systems (the only one with SCSI). I presume the cabling is substandard, but given my coordination deficits and the rarity of the errors I'd do far more damage replacing it than leaving it be.
I had one of these today. The system (2.6.23.9) spotted the error, and seemingly recovered: Dec 1 12:53:40 loki warning: kernel: sym0: SCSI parity error detected: SCR1=132 DBC=50000000 SBCL=0 Dec 1 12:53:40 loki warning: kernel: sym0:0: ERROR (81:0) (8-0-0) (10/9d/0) @ (mem c2800048:ffffffff). Dec 1 12:53:40 loki warning: kernel: sym0: regdump: da 00 00 9d 47 10 00 0e 00 08 80 00 80 00 0f 0a d0 58 3c 01 02 ff ff ff. Dec 1 12:53:40 loki warning: kernel: sym0: SCSI BUS reset detected. Dec 1 12:53:40 loki notice: kernel: sym0: SCSI BUS has been reset. However, after that reset I/O to any device on that controller is *incredibly* slow. A monthly RAID check kicked off shortly afterwards and provided my first clue. Load average >15, and: md1 : active raid5 sda6[0] hdc5[3] sdb6[1] 76807296 blocks super 1.2 level 5, 64k chunk, algorithm 2 [3/3] [UUU] [========>............] check = 42.8% (16450780/38403648) finish=253.3min speed=1442K/sec 1442Kb/s is a bit less than I'd expect from a three-drive array with disks capable of 40Mb/s easily. /dev/sda: Timing buffered disk reads: 8 MB in 3.50 seconds = 2.29 MB/sec A somewhat slower ATAPI disk on the same machine: /dev/hdc: Timing buffered disk reads: 110 MB in 3.05 seconds = 36.08 MB/sec So, um, what could cause this? Can I speed it up again other than by rebooting (which I'm just about to do, but it is annoying). -- `Some people don't think performance issues are "real bugs", and I think such people shouldn't be allowed to program.' --- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/