ionice + cp = тормоза

[root@host northsoft]# hdparm -X69 /dev/sdb
/dev/sdb:
 setting xfermode to 69 (UltraDMA mode5)
 HDIO_DRIVE_CMD(setxfermode) failed: Invalid exchange
[root@host northsoft]# cat /sys/block/sdb/queue/scheduler
noop anticipatory deadline [cfq]
[root@host northsoft]#