Generate IO to /dev/vdb, attached to cinder volume

asked 2014-11-18 00:45:17 -0500

Pradip gravatar image

updated 2014-11-18 01:52:18 -0500

dbaxps gravatar image


One of my Cinder volume is attached to a Fedora instance where I am having the volume appeared in /dev/vdb.

I did the following:

  sudo fdisk -l   
  sudo mkfs -t ext3 -V /dev/vdb

[fedora@myvm1 ~]$ sudo fdisk -l

Disk /dev/vda: 20 GiB, 21474836480 bytes, 41943040 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00021380

Device    Boot Start       End   Blocks  Id System
/dev/vda1 *     1953  41942989 20970518+ 83 Linux

Disk /dev/vdb: 1 GiB, 1073741824 bytes, 2097152 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

[fedora@myvm1 ~]$ uname -a Linux myvm1 3.11.10-301.fc20.x86_64 #1 SMP Thu Dec 5 14:01:17 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

Now I would like to generate some IO to the /dev/vdb disk.

Any suggestion which inbuild tool, simple script I can use?

Any pointer would be appreciated.

Basic Aim: Want to create some IO to the LUN and see it's impact upto the underlying storage through cinder.

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answered 2014-11-18 01:10:51 -0500

sbfox gravatar image

There are many io generators available. The simplest is dd then going up to packages like bonnie++ and fio

dd if=/dev/zero of=1g.bin bs=1G count=1

On the hypervisor you have tools like iotop and sar to monitor the IO load the vm in generating. If its a network volume (ceph/iscsi for example) can use iftop to see the network working as well

Hope that helps

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Yes, it helped.

Pradip gravatar imagePradip ( 2014-11-18 08:03:51 -0500 )edit

answered 2014-11-18 03:43:16 -0500

j-harbott gravatar image

If you want a flexible IO benchmark tool, would probably be the best candidate.

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Exploring how to use it. Thanks for the nice pointer.

Pradip gravatar imagePradip ( 2014-11-18 08:04:11 -0500 )edit

answered 2014-11-18 01:55:50 -0500

Ram.Meena gravatar image

updated 2014-11-18 01:58:25 -0500


To generate IO you may use 'dd' linux inbuilt command to generate files with garbage data. You will need to mount the device (/dev/vdb) on some directory in file system and generate the data into mounted directory using 'dd'. There are several references available on web to use this command.

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Thanks Meena Ram. 'dd' can be a choice. But other than 'dd', can I have something which I can use to generate IO traffic like IOMeter? Say 20%-80% Random-Seq .... like that? That would be awesome.

Pradip gravatar imagePradip ( 2014-11-18 02:18:18 -0500 )edit

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Asked: 2014-11-18 00:45:17 -0500

Seen: 1,646 times

Last updated: Nov 18 '14