CODEWITHSUNDEEP
unixhp-uxdisk-io
Cac3a
Cac3a

Reputation: 124

Trobleshooting slow writes on hpux

Could anyone offer any troubleshooting ideas or pointers on where/how to get more information on the difference between sys and real time from the output below?

It is my understanding that the command finished processing in the OS in 4 seconds, but then IO where queued and processing and 38.3 seconds (is that right?). It is somewhat a block box at this point to me on how to get some additional details.

time prealloc /myfolder/testfile 2147483648

real       42.5
user        0.0
sys         4.2

Upvotes: -1

Views: 121

Answers (1)

fork2execve
fork2execve

Reputation: 1650

You are writing 2 GB to disk on an HP-UX system; this is most likely using spinning disks (physical hard disks).

The system is writing 2GiB / 42s = 51 MB/s which doesn't sound slow to me.

On these systems you can use tools such as sar. Use sar -ud 5 to see CPU and disk usage during your prealloc command; you will likely see disk usage pegged at 100%.

Upvotes: 0

Related Questions