What tests do I need to report slow disk speeds to tech support?

rchurch

What tests do I need to report slow disk speeds to tech support?

Read speeds have dropped very low, and write speeds are not that good, but passable. I need tests for both.

4n0nx

I searched for fdatasync and copied the first result

dd if=/dev/zero of=test bs=64k count=16k conv=fdatasync

vfuse

You can use iostat / iotop to monitor things.

rchurch

@vfuse said:
You can use iostat / iotop to monitor things.

Can iostat and iotop generate a report or a graph for a given time period?

For the mean time I am interested in an equivalent of the dd write speed test, which can give info on how slow read speeds are.

vfuse

@rchurch said:
For the mean time I am interested in an equivalent of the dd write speed test, which can give info on how slow read speeds are.

You can create a cronjob:

• • • • • root iotop -botqqq --iter=3 >> /var/log/iotop

Clouvider

iotop shows I/O usage aggregated per process. How does this prove the disk is slow? Max it can prove that some process is hogging the disk, if any.

DD is a good idea but no graph. Have you considered simply doing one test and reporting to support?

jazz1611

Follow this tutorial and you will get result: https://www.binarylane.com.au/support/solutions/articles/1000055889-how-to-benchmark-disk-i-o

Nyr

If your server is really slow and you still need to prove it for the support to fix it, there is something seriously wrong.

thsigit

Try Cloudlook http://www.cloudlook.com/

jlay

You might want to consider testing using hdparm.

For example:
[root@db1 ~]# hdparm -Tt /dev/xvda

/dev/xvda:
Timing cached reads: 17114 MB in 2.00 seconds = 8569.12 MB/sec
Timing buffered disk reads: 918 MB in 3.00 seconds = 305.59 MB/sec

century1stop

how do you know disk rw is low if relevant tests have not been performed?