Instruction Manual

148 Troubleshooting
Linux Operating System Errors
Table 9-7 describes issues related to the Linux operating system.
Table 9-7. Linux Operating System Errors
Error Message Corrective Action
<Date:Time> <HostName>
kernel: sdb: asking for
cache data failed
<Date:Time> <HostName>
kernel: sdb: assuming
drive cache: write
through
This error message is displayed when the Linux
Small Computer System Interface (SCSI)
mid-layer asks for physical disk cache settings.
The controller firmware manages the virtual disk
cache settings on a per controller and a per
virtual disk basis, so the firmware does not
respond to this command. 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 108 for more information about
Write-Through cache.
Except for this message, there is no effect of this
behavior on normal operation. The cache policy
of the virtual disk and the I/O throughput are
not affected by this message. The cache policy
settings for the PERC H700 and PERC H800
SAS RAID system remain unchanged.
PERC7.2_UG.book Page 148 Thursday, March 3, 2011 2:14 PM