Fujitsu SPARC T5440 User Manual page 89

Fixed Firmware and General Software Issues (Continued)
TABLE A-4
CR ID Description
6682500 Applications performing a large amount of
virtual disk I/O in an LDOMS guest domain can
hang in a state that requires rebooting both the
control and guest domains.
Workaround
Note - Fixed in System Firmware 7.2.2.e or later.
If your application performs more than 30,000 IO
operations per second, configure the server so that
the application performs physical I/O instead of
virtual I/O. Do one of the following:
• Run the application in the control domain.
• Export the root nexus containing the disk
devices to the guest domain that will be running
the application.
If neither of these workarounds is possible, contact
your service representative to determine if a patch
for this problem is available.
Use the iostat(1) command to determine the
number of system-wide disk I/O
operations-per-second (IOPS). For example:
# iostat -x 1 30
This produces a line of output per device, every
second, for 30 seconds (30 total samples).
The sum of reads per second (r/s) and writes per
second (w/s) for each interval provides a
system-wide IOPS metric. For example:
extended device statistics
device r/s
wait actv svc_t
md2 0.0
0.0 0.0 31.9
. . .
Disregard the first interval. (This represents
metrics since the system was booted.)
The columns of interest are the second and third
column from the left (r/s, w/s). Of the remaining
29 intervals, select the interval with the largest
number of total IOPS (the sum of r/s and w/s for
all devices) to determine if the application
approaches (or exceeds) the 30,000 IOPS threshold.
Appendix A
w/s kr/s kw/s
%w %b
2.0 0.0 12.0
3 4
Fixed Issues 79