HP VMA Series, Инструкция по установке и обслуживанию

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Violin Utilities Reference
HP-AM456-9002A Rev 01 VMA-series Memory Array Installation and Service Guide
165
Example
By default, the
perf_test
accesses the first Memory Array device using a
single thread for a repeated 4kB read of sector 0. For best results, use the
-R
option to randomly access a specific range (
-s
) using multiple threads (
-t
),
direct I/Os (
-o
), and asynchronous I/Os (
-A
).
-A async-io-depth
Specifies the number of I/Os to generate using the
operating system’s asynchronous I/O API.
On Linux, this option is only available if the
libaio
and
libaio-devel
packages were installed with
the Violin Utilities installation. Specify less threads
using the
-t
option for Windows and Linux drivers
and specify more asynchronous I/Os using the
-A
option, as it reduces CPU context switching.
-a address
Specifies the address, in hex, where read/write
operations occur or start. Useful with the
-C
option
for sequential reads and writes.
-c char
Specifies a character, in hex, to write when
performing write operations. Example:
0xCA
.
-V
Verifies writes with a read to ensure data integrity.
This option can have a significant impact on overall
I/O throughput.
-I
Ignores errors on read/write operations to the
device.
-R
Selects addresses to read/write randomly.
-C
Selects addresses to read/write incrementing by
the block size specified.
-q
Specifies quiet mode. Prints a summary of
information only just before exiting and not every
second. This option is useful when using
perf_test
in a scripted environment.
-z
Specifies print timestamps as real time instead of
number of seconds elapsed since the start of the
test.
-L
Specifies latency mode.
-u
Prints detailed system utilization statistics.
-o
Informs
perf_test
to bypass the buffer cache by
using the
O_DIRECT
flag when opening a
connection to the device-path. This option applies to
block devices only and not character devices.
Table 9.2 perf_test Utility Options (Continued)
Option Description