Hi recently I noticed in the messages log, the following error May 18 15:59:52 mail kernel: sdb: assuming drive cache: write through May 18 15:59:52 mail kernel: sdb : READ CAPACITY failed. May 18 15:59:52 mail kernel: sdb : status=0, message=00, host=1, driver=00 May 18 15:59:52 mail kernel: sdb : sense not available. May 18 15:59:52 mail kernel: sdb: assuming Write Enabled May 18 15:59:52 mail kernel: sdb: assuming drive cache: write through May 18 15:59:52 mail kernel: sdb:<3>Buffer I/O error on device sdb, logical block 0 May 18 15:59:52 mail kernel: Buffer I/O error on device sdb, logical block 0 May 18 15:59:52 mail last message repeated 5 times May 18 15:59:52 mail kernel: unable to read partition table I'm not sure what sdb is since its not listed on my partition table [root at mail srvadmin]# fdisk -l Disk /dev/sda: 109.1 GB, 109196476416 bytes 255 heads, 63 sectors/track, 13275 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 * 1 13 104391 83 Linux /dev/sda2 14 13275 106527015 8e Linux LVM [root at mail srvadmin]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/VolGroup00-LogVol00 99G 42G 52G 45% / /dev/sda1 99M 44M 51M 47% /boot none 3.9G 0 3.9G 0% /dev/shm [root at mail srvadmin]# I looked at the hardware itself and all disk in this raid system are fine, my question is, is this something I need to worry about and what is causing this issue. Although everything looking fine, my messages log is full of sdb complaints. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20090518/e1366d55/attachment-0004.html>