Dell PowerEdge RAID Controller 6i - Manual (Page 125)

Troubleshooting
125
Linux Operating System Errors
Table 7-8 describes issues related to the Linux operating system.
Table 7-8. Linux Operating System Errors
Error Message Suggested Solution
kernel: sdb: asking for
cache data failed
kernel: sdb: assuming
drive cache: write
through
This error message displays when the Linux
Small Computer System Interface (SCSI)
mid-layer asks for physical disk cache settings.
Because the controller firmware manages the
virtual disk cache settings on a per controller
and a per virtual disk basis, the firmware does
not respond to this command. Thus, the Linux
SCSI mid-layer assumes that the virtual disk's
cache policy is Write-Through. SDB is the device
node for a virtual disk. This value changes for
each virtual disk.
See the section "Physical Disk Management" on
page 104 for more information about Write-
Through cache.
Except for this message, there is no side effect to
this behavior. The cache policy of the virtual
disk and the I/O throughput are not affected by
this message. The cache policy settings for the
PERC6 SAS RAID system remain the settings
you have already chosen.
Dell_PERC6.1_UG.book Page 125 Wednesday, April 15, 2009 4:18 PM