If fdisk -l sees no /dev/sdb5, I'm wondering what kind of problem you are suffering. What is the contents of /proc/partitions?

Did you run fdisk -l on sys52 ???

#fdisk -l
<---- Disk: /dev/sda ---->


Disk /dev/sda: 73.4 GB, 73407865856 bytes
255 heads, 63 sectors/track, 8924 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 1058 8393962+ 82 Linux swap
/dev/sda3 1059 8924 63183645 83 Linux

<---- END ---->
<---- Disk: /dev/sdb ---->


<---- END ---->
<---- Disk: /dev/sdc ---->


<---- END ---->

#more proc/partitions
major minor #blocks name rio rmerge rsect ruse wio wmerge wsect wuse runni
ng use aveq

8 0 71687369 sda 480938 1011060 11824556 943580 681049 4920186 44845318
1775628 0 4387990 3028338
8 1 104391 sda1 321 17329 35300 1170 71 60 262 62160 0 51210 63330
8 2 8393962 sda2 27 66 336 70 109 12233 98736 284990 0 78930 285060
8 3 63183645 sda3 480395 993005 11787210 940970 680869 4907893 44746320
1428488 0 4308930 2678548
8 16 1048575 sdb 32 96 256 30 0 0 0 0 0 30 30
8 32 1048575 sdc 105683 19585 125440 26770 6 0 6 220 0 16410 26990

My Linux Box suffers the following I/O error. From the analysis above, I think the I/O error occurs at the 5th slice of the secondary scsi hard disk. I want to know how to fix the I/O error
--- fsck ?

Jul 18 04:03:20 sys52 kernel: Directory sread (sector 0x1f5) failed
Jul 18 04:03:20 sys52 kernel: I/O error: dev 08:21, sector 501

According to your system, /dev/sdb has no partitions, so the error with 08:21 is very odd. What is on the sdb disk?

Some Read failure to sdb.


I think the sdb can not be recognized by kernel.

well, maybe post dmesg from sys52..

I found sys52 just one SCSI disk connected. I stopped the cron job, then the dev I/O error disappeared.

Thank you.