Any tool like dd, which can issue lot of reads on file-system, for Solaris

UNIX for Advanced & Expert Users
1

Hi,
I have x86 Solaris 10, running on VMWare. I am facing a performance issue on this. There are 5 NGZ running on this server. Whenever netbackup is running on this server, one of the zone started seeing CPU utilization goes as high as 80% and load average to 40-50. Here is example -

-bash-3.2# zoneadm list -icv
  ID NAME       STATUS     PATH             BRAND    IP
   0 global 	running    /                native   shared
   1 zone1    	running    /zones/zone1     native   shared
   2 zone2      running    /zones/zone2     native   shared
   3 zone3     	running    /zones/zone3     native   shared
   4 zone4    	running    /zones/zone4     native   shared
   5 zone5     	running    /zones/zone5     native   shared
-bash-3.2#

It is always zone2, which sees high utilization when netbackup runs. If I run prstatat it tells me it is zpool-zone2/162 which consumes all CPU. "zpool iostat" tells me that IO are very on this pool.

I am still trying to figure it out, but I need another tool to test READs on this filesystem. Instead of waiting for netbackup to run an then I monitor, is there any other command, which can generate lot of READs on /zones/zone2 ?
I could find some dd commands (first write and then read) for Linux, but can't see a valid one for Solaris.

Please suggest.

Thanks

2

dd is ancient, so it should be present, what happens when you do

ls /usr/bin/dd
man dd
3

Yes dd is there, but its man page tells about copying but I missed to see example of read. Can you help me with full command?

4

To just read, you can output to /dev/null

For example the following command

time dd if=/some/path of=/dev/null bs=64k count=1024

Would read 64 MiB in blocks of 64kiB .
The time command will give you an indication on how long it takes.

You can vary the block size, it can be that one of the zones has a lot of very small files, which takes a lot more effort and is a lot slower, than a few large files.

2 Likes
5

Thanks, it works for me

6

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