Hi Justin, I did some testing with iscsi a year or so ago. It was just using standard rbd images in the backend so yes I think your theory of stopping iscsi to release the locks and then providing access to the rbd image would work. Rich On Wed, 17 Mar 2021 at 09:53, Justin Goetz <jgoetz@xxxxxxxxxxxxxx> wrote: > > Hello! > > I was hoping to inquire if anyone here has attempted similar operations, > and if they ran into any issues. To give a brief overview of my > situation, I have a standard octopus cluster running 15.2.2, with > ceph-iscsi installed via ansible. The original scope of a project we > were working on changed, and we no longer need the iSCSI overhead added > to the project (the machine using CEPH is Linux, so we would like to use > native RBD block devices instead). > > Ideally we would create some new pools and migrate the data from the > iSCSI pools over to the new pools, however, due to the massive amount of > data (close to 200 TB), we lack the physical resources necessary to copy > the files. > > Digging a bit on the backend of the pools utilized by ceph-iscsi, it > appears that the iSCSI utility uses standard RBD images on the actual > backend: > > ~]# rbd info iscsi/pool-name > rbd image 'pool-name': > size 200 TiB in 52428800 objects > order 22 (4 MiB objects) > snapshot_count: 0 > id: 137b45a37ad84a > block_name_prefix: rbd_data.137b45a37ad84a > format: 2 > features: layering, exclusive-lock, object-map, fast-diff, deep-flatten > op_features: > flags: object map invalid, fast diff invalid > create_timestamp: Thu Nov 12 16:14:31 2020 > access_timestamp: Tue Mar 16 16:13:41 2021 > modify_timestamp: Tue Mar 16 16:15:36 2021 > > And I can also see that, like a standard rbd image, our 1st iSCSI > gateway currently holds the lock on the image: > > ]# rbd lock ls --pool iscsi pool-name > There is 1 exclusive lock on this image. > Locker ID Address > client.3618592 auto 259361792 10.101.12.61:0/1613659642 > > Theoretically speaking, would I be able to simply stop & disable the > tcmu-runner processes on all iSCSI gateways in our cluster, which would > release the lock on the RBD image, then create another user with rwx > permissions to the iscsi pool? Would this work, or am I missing > something that would come back to bite me later on? > > Looking for any advice on this topic. Thanks in advance for reading! > > -- > > Justin Goetz > Systems Engineer, TeraSwitch Inc. > jgoetz@xxxxxxxxxxxxxx > 412-945-7045 (NOC) | 412-459-7945 (Direct) > > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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