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Ceph for Windows - Volume Expansion

asked 2023-01-31 16:59:26 +0300

mstidham gravatar image

We're currently evaluating the Ceph for Windows driver and we've noticed a couple of limitations of the driver.

First, if the rbd volume size is increased on the backend; the ceph for windows driver does not automatically detect the change in available space. We have to unmount and remount the rbd, via the ceph for windows driver, for the increased space to be available to Windows. - Are you currently aware of this limitation? - Is this already on your roadmap to include in future release; or is this currently a correctable issue?

Second, it appears that the only keyring that can be used to connect the ceph for windows driver to the ceph backend is the admin keyring. This gives the Windows Host full permissions to Ceph. Am I doing something wrong or is this a current limitation of the driver? We would like to restrict the host to only be able to mount, unmount, read, and write to rbd volumes. I believe this could be controlled via a custom keyring but it doesn't appear that we can use any keyring except the admin keyring.


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answered 2023-01-31 17:37:35 +0300

lpetrut gravatar image


We've recently added live resize support, basically watching for rbd resize events and notifying the driver accordingly. If needed, we can backport this feature to Quincy.

The keyring handling is not platform specific and you should be able to use non-admin keyrings. Please paste the output of the following command, omitting the key: "ceph auth get client.$user".

You'll most probably want something like this:

ceph auth get-or-create client.$user mon 'profile rbd' osd 'profile rbd pool=rbd'

Regards, Lucian

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That's excellent news about the resize support. I'd hate to ask you to backport it if it's going to be available soon in a new release. If you can backport it that would be great; otherwise, do you know when it will be available to download?

mstidham gravatar imagemstidham ( 2023-02-01 17:18:35 +0300 )edit

I've tried an entirely new admin keyring and "rbd ls {pool}" shows rbd: couldn't connect to cluster. I edited the ceph.conf and changed the line for the keyring to ceph.client.hostadmin.keyring. [client.hostadmin] caps mds = "allow *" caps mon = "allow *" caps osd = "allow *"

mstidham gravatar imagemstidham ( 2023-02-01 17:20:11 +0300 )edit

The next official Ceph release (Reef) is scheduled for late June: However, I've just backported the resize patch to our downstream Quincy branch and triggered a new build. It should be available later today.

lpetrut gravatar imagelpetrut ( 2023-02-02 10:02:05 +0300 )edit

Downloaded the new driver and the resize problem seems resolved. Thank you. Any suggestions on why using a different "admin" keyring results in "rdb: couldn't connect to cluster"? I have two keyring files with the same permissions. All I changed was the keyring line in ceph.conf to the new one.

mstidham gravatar imagemstidham ( 2023-02-03 17:03:35 +0300 )edit

Do the keyring files have the same content? Can you double check the paths? It might be that nodepad added a .txt extension.

lpetrut gravatar imagelpetrut ( 2023-02-06 10:28:55 +0300 )edit

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Asked: 2023-01-31 16:59:26 +0300

Seen: 702 times

Last updated: Jan 31 '23