디스크 I/O 를 좀 높여 보기 위해서 아래와 같이 fstab 설정을 변경해봤습니다.
 /dev/sda3   /home   ext3    defaults,noatime  1 2
  noatime 옵션은 접근 정보를 저장하지 않는 것으로 알고 있는데요.
 /home 부분은 없어도 될거 같아서 위와 같이 설정을 해봤습니다.
 그런데 하루정도 지난뒤 문제가 생겼는데요.
 I/O 쪽에 에러가 나더군요.
  Dec 25 08:48:52 www kernel: aacraid:ID(0:02:0); Error Event [command:0x28]
Dec 25 08:48:52 www kernel: aacraid:ID(0:02:0); Medium Error [k:0x3,c:0x15,q:0x1]
Dec 25 08:48:52 www kernel: aacraid:ID(0:02:0); Mechanical Positioning Error
Dec 25 08:49:08 www kernel: aacraid:ID(0:02:0) Timeout detected on cmd[0x28]
Dec 25 08:49:08 www kernel: aacraid:SCSI Channel[0]: Timeout Detected On 6 Command(s)
Dec 25 08:49:08 www kernel: aacraid:ID(0:02:0); Aborted Command [command:0x28]
Dec 25 08:49:08 www kernel: aacraid: <...repeats 1 more times>
Dec 25 08:49:08 www kernel: aacraid:ID(0:02:0) - IO failed, Cmd[0x28]
Dec 25 08:49:08 www kernel: aacraid:Mirror Container 2 Drive 0:2:0 Failure
Dec 25 08:49:27 www kernel: aacraid:SCSI Channel[0]: Timeout Detected On 3 Command(s)
Dec 25 08:49:47 www kernel: aacraid:ID(0:02:0) Timeout detected on cmd[0x28]
Dec 25 08:49:47 www kernel: aacraid:SCSI Channel[0]: Timeout Detected On 3 Command(s)
Dec 25 08:50:01 www kernel: aacraid: Host adapter reset request. SCSI hang ?
Dec 25 08:50:08 www kernel: aacraid: <...repeats 1 more times>
Dec 25 08:50:08 www kernel: aacraid:Container 2 started REBUILD task on drive 0:2:0
Dec 25 08:50:11 www kernel: aacraid: Host adapter reset request. SCSI hang ?
Dec 25 08:50:21 www kernel: scsi: device set offline - command error recover failed: host 0 channel 0 id 2 lun 0
Dec 25 08:50:21 www kernel: SCSI disk error : host 0 channel 0 id 2 lun 0 return code = 6000000
Dec 25 08:50:21 www kernel:  I/O error: dev 08:21, sector 34896264
Dec 25 08:50:21 www kernel:  I/O error: dev 08:21, sector 29113744
Dec 25 08:50:21 www kernel:  I/O error: dev 08:21, sector 3145824
Dec 25 08:50:21 www kernel:  I/O error: dev 08:21, sector 6319080
Dec 25 08:50:21 www kernel:  I/O error: dev 08:21, sector 6319216
Dec 25 08:50:21 www kernel:  I/O error: dev 08:21, sector 29098072
Dec 25 08:50:21 www kernel:  I/O error: dev 08:21, sector 29113288
Dec 25 08:50:21 www kernel: EXT3-fs error (device sd(8,33)): ext3_get_inode_loc: unable to read inode block - inode=1815
293, block=3637259 Dec 25 08:50:21 www kernel:  I/O error: dev 08:21, sector 29113352
Dec 25 08:50:21 www kernel:  I/O error: dev 08:21, sector 29113472
Dec 25 08:50:21 www kernel:  I/O error: dev 08:21, sector 29113592
Dec 25 08:50:21 www kernel:  I/O error: dev 08:21, sector 29113744
Dec 25 08:50:21 www kernel:  I/O error: dev 08:21, sector 34896264
  보시면 아시겠지만... 크리스 마스 아침을 망치게 T_T
 결국 위의 옵션을 다시 원상태로 바꾸고는 현재 이상이 없습니다.
 이에 관해서 아시는 분은 좀 알려주세요.
  DELL 서버 이구요. 레드핫 7.2  커널 2.4.18-18.7.xsmp
 aacraid 레이드 카드에 밀러링 sda 가 잡혀있구요. sdc는 그냥 싱글로 잡혀있습니다.