Calculate hdisk READ / WRITE throughput (sequential IO) from AIX systems.

Do you know the throughput of your disks? This time we’re going to calculate read / write throughput of hdisks from an AIX system.

  • Let’s create a file for this test.
[root@aix:/] lptest 127 32 > /tmp/file
[root@aix:/] ls -ltr /tmp/file
-rw-r-----    1 root     system         4096 Feb 07 16:22 /tmp/file
  • Let’s make a sequential WRITE test.
[root@aix:/]  timex dd if=/dev/zero of=/tmp/file  bs=1m count=1000
1000+0 records in.
1000+0 records out.

real 2.96
user 0.00
sys  1.67
  • Now divide 2014 / “real” number to get MB/s throughput.
    In this example:
1024 MB / 2.96 s = 345 MB/s

WRITE throghput is 345 MB/s

  • Let’s make a sequential READ test.
[root@aix:/] timex dd if=/dev/rhdisk3 of=/dev/null bs=1m count=1024
2048+0 records in.
2048+0 records out.

real 4.83
user 0.00
sys  0.32
  • Now divide 2014 / “real” number to get MB/s throughput.
    In this example:
1024 MB / 4.83 s = 212 MB/s

READ throghput is 345 MB/s

 

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About igalvarez

More than 20 years experiences on IT industry. 20+ years in Unix experience : IBM-AIX, HMC/SDMC/IVM, SVC, Protectier, PureFlex Systems, VIOservers, IBM Bladecenters, IBM System Power, RedHat Linux, SuSE Linux, Debian/Ubuntu Linux. Solaris, SCO Unix, Tru64 Unix, Linux Virtualization: XEN, KVM, databases sb2, oracle, postgreSQL, Find more information here: http://en.gravatar.com/igalvarez
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