Notes and gotchas on the Volumes Management section of Compute Admin manual

[Anne Gentle]

ref: http://docs.openstack.org/diablo/openstack-compute/admin/content/managing-volumes.html

Anne, I saw your reference to an overhaul of this part of the doc. I happened to have just finished a long struggle with this. Here is my report (using oneiric):

1. Funny quotes: sed -i ‘s/false/true/g’ /etc/default/iscsitarget. They confuse the shell when pasted.
2. Installing open-iscsi does not create /etc/default/iscsitarget, needed to install iscsitarget.
3. Restarting iscsitarget gives "FATAL: Module iscsi_trgt not found." so needed to install iscsitarget-dkms.
4. The volume code calls 'ietadm' but the /etc/sudoers.d/nova_sudoers thinks it is using 'tgtadm'. This is a packaging bug, not doc.
5. You have to install iscsi on the controller also because it is running compute. The doc says "only compute nodes" in bold.
6. 'iscsiadm' is misspelled as 'iscsciadm' in some places.
7. iscsciadm -m session may return nothing when run on the controller but volumes seem to work.

And finally the most painful: when I had no hair left after trying to figure out why I couldn't see the disk in the guest, I discovered
https://answers.launchpad.net/nova/+question/165695
which informed me that if you are using kvm then the actual device name in the guest will be different than the one
specified in the attach command. The doc needs to say this!

I hope this is useful. If not, or if there is someplace else I should put such experiences, please let me know.

As a larger issue, I have gotten a lot of information about of the openstack docs and they are well written. My biggest problem has been that honestly, as often than not, when explicit actions or commands are spelled out they don't work!

[Openstack Gerrit (openstack-gerrit)]

Reviewed: https://review.openstack.org/819
Committed: http://github.com/openstack/openstack-manuals/commit/d75b8d47f2c4ab4c36c11b55e9933e07438bfd93
Submitter: Jenkins
Branch: master

 status fixcommitted
 done

commit d75b8d47f2c4ab4c36c11b55e9933e07438bfd93
Author: annegentle <email address hidden>
Date: Fri Oct 7 13:49:25 2011 -0500

    bug 868595, new volumes management info

    Change-Id: I8ea02cee735020d50946264cfbca2b33b966e8c5

[Tristan (tristanvanbokkem)]

I am having this issue of point #3 as well "Restarting iscsitarget gives "FATAL: Module iscsi_trgt not found." so needed to install iscsitarget-dkms."

The PDF reads only half the line:

This package could refuse to start with a "FATAL: Module iscsi_trgt not found" error. This error is caused by

and the next line:

apt-get install iscsitarget-dkms (the Dynamic Kernel Module Support is a framework used for

So besides the bugged pdf, is there any other solution? the installation of iscsitarget-dkms did not solved it.

[Razique Mahroua (razique)]

What $ m-a a-i iscsitarget followed by modprobe iscsi_trgt gives ?

[Tristan (tristanvanbokkem)]

Running:
 apt-get install iscsitarget-source
Followed by:
 m-a a-i iscsitarget
and lastly:
 modprobe iscsi_trgt
seems to work.

So for me, only the bugged pdf is the remaining issue :)

[PranavS (pranav-sahasrabudhe)]

Sometimes, the 'FATAL' error persists. In this case, after a lot of googling, I found following solution working for me:

apt-get install --reinstall iscsitarget-dkms

Hope this helps....

Cheers,
PS