With md raid1 instead of dm-mirror i get no lockups during similar workloads or any other workload i've managed to produce. Everything is the same except that i'm using md instead of dm-mirror. >Disk io deadlocks during large-file io. > >During heavy disk io involving creating large files, some parts >of the kernel locks up. In most cases all disk output becomes >impossible, but sometimes you can write small things to disk, like >echo > test.txt might work sometimes. On reiserfs the lockups tend to be >more severe. The problem only occurs when i have both disks in my device >mapper mirror installed. if i remove one of the SATA cables, everything >works perfectly , except that devicemapper complains that the mirror is >degraded. > > See previous mail for complete information about the problem, or feel free to ask me for any further details. I'll try running dm-mirror on two other disks i've got which is on another controller to see if i can reproduce the problem there also. /Mikael Andersson