If I'm understanding your question / setup correctly, the best way would be to simply mount -o bind the old path to the new one. The old path would still be used by gluster, but it would ultimately go to the new location.
Changing the brick path on a single brick while leaving the original path intact on others may be possible, the gluster docs are silent either way, but I'd doubt oVirt would work correctly in that circumstance. Maybe Sandro can point us at someone who would know more on that subject? :) If it is possible to do, and standard disclaimer: I'm *NOT* recommending anyone do it, I'd imagine you'd need to follow instructions similar to (https://serverfault.com/questions/631365/rename-a-glusterfs-peer) replacing the peer name with the brick directory. -Patrick Hibbs On Mon, 2022-07-18 at 08:19 +0300, Gilboa Davara wrote: > Hello, > > Many thanks for your email. > I should add that this is a test environment we set up in preparation > for a planned CentOS 7 / oVirt 4.3 upgrade to CentOS 8 Streams / > oVirt 4.5 upgrade in one of our old(er) oVirt clusters. > In this case, we blew up the software RAID during the OS replacement > (CentOS 7 -> 8) so have a host, but no storage. > And as an added bonus, the FS locations are a bit different. (due MD > changes we made during the blowup). > > So, essentially the host is alive, but we need to create a new brick > using a known good brick. > A couple of questions: > Assuming I have a known good brick to copy but the FS location is > different and given the fact I cannot simply remove/add brick, how do > I change the brick path? > Old location: > office-wx-hv1-lab-gfs:/mnt/LogGFSData/brick > New location: > office-wx-hv1-lab-gfs.localdomain:/gluster/brick/data/brick > > Thanks again, > Gilboa > > On Mon, Jul 18, 2022 at 1:32 AM Patrick Hibbs > <hibbsncc1...@gmail.com> wrote: > > What you are missing is the fact that gluster requires more than > > one set of bricks to recover from a dead host. I.e. In your set up, > > you'd need 6 hosts. 4x replicas and 2x arbiters with at least one > > set (2x replicas and 1x arbiter) operational bare minimum. > > Automated commands to fix the volume do not exist otherwise. (It's > > a Gluster limitation.) This can be fixed manually however. > > > > Standard Disclaimer: Back up your data first! Fixing this issue > > requires manual intervention. Reader assumes all responsiblity for > > any action resulting from the instructions below. Etc. > > > > If it's just a dead brick, (i.e. the host is still functional), all > > you really need to do is replace the underlying storage: > > > > 1. Take the gluster volume offline. > > 2. Remove the bad storage device, and attach the replacement. > > 3. rsync / scp / etc. the data from a known good brick (be sure to > > include hidden files / preserve file times and ownership / SELinux > > labels / etc. ). > > 4. Restart the gluster volume. > > > > Gluster *might* still need to heal everything after all of that, > > but it should start the volume and get it running again. > > > > If the host itself is dead, (and the underlying storage is still > > functional), you can just move the underlying storage over to the > > new host: > > > > 1. Take the gluster volume offline. > > 2. Attach the old storage. > > 3. Fix up the ids on the volume file. > > (https://serverfault.com/questions/631365/rename-a-glusterfs-peer) > > 4. Restart the gluster volume. > > > > If both the host and underlying storage are dead, you'll need to do > > both tasks: > > > > 1. Take the gluster volume offline. > > 2. Attach the new storage. > > 3. rsync / scp / etc. the data from a known good brick (be sure to > > include hidden files / preserve file times and ownership / SELinux > > labels / etc. ). > > 4. Fix up the ids on the volume file. > > 5. Restart the gluster volume. > > > > Keep in mind one thing however: If the gluster host you are > > replacing is used by oVirt to connect to the volume (I.e. It's the > > host named in the volume config in the Admin portal). The new host > > will need to retain the old hostname / IP, or you'll need to update > > oVirt's config. Otherwise the VM hosts will wind up in Unassigned / > > Non-functional status. > > > > - Patrick Hibbs > > > > On Sun, 2022-07-17 at 22:15 +0300, Gilboa Davara wrote: > > > Hello all, > > > > > > I'm attempting to replace a dead host in a replica 2 + arbiter > > > gluster setup and replace it with a new host. > > > I've already set up a new host (same hostname..localdomain) and > > > got into the cluster. > > > > > > $ gluster peer status > > > Number of Peers: 2 > > > > > > Hostname: office-wx-hv3-lab-gfs > > > Uuid: 4e13f796-b818-4e07-8523-d84eb0faa4f9 > > > State: Peer in Cluster (Connected) > > > > > > Hostname: office-wx-hv1-lab-gfs.localdomain <------ This is a new > > > host. > > > Uuid: eee17c74-0d93-4f92-b81d-87f6b9c2204d > > > State: Peer in Cluster (Connected) > > > > > > $ gluster volume info GV2Data > > > Volume Name: GV2Data > > > Type: Replicate > > > Volume ID: c1946fc2-ed94-4b9f-9da3-f0f1ee90f303 > > > Status: Stopped > > > Snapshot Count: 0 > > > Number of Bricks: 1 x (2 + 1) = 3 > > > Transport-type: tcp > > > Bricks: > > > Brick1: office-wx-hv1-lab-gfs:/mnt/LogGFSData/brick <------ This > > > is the dead host. > > > Brick2: office-wx-hv2-lab-gfs:/mnt/LogGFSData/brick > > > Brick3: office-wx-hv3-lab-gfs:/mnt/LogGFSData/brick (arbiter) > > > ... > > > > > > Looking at the docs, it seems that I need to remove the dead > > > brick. > > > > > > $ gluster volume remove-brick GV2Data office-wx-hv1-lab- > > > gfs:/mnt/LogGFSData/brick start > > > Running remove-brick with cluster.force-migration enabled can > > > result in data corruption. It is safer to disable this option so > > > that files that receive writes during migration are not migrated. > > > Files that are not migrated can then be manually copied after the > > > remove-brick commit operation. > > > Do you want to continue with your current cluster.force-migration > > > settings? (y/n) y > > > volume remove-brick start: failed: Removing bricks from replicate > > > configuration is not allowed without reducing replica count > > > explicitly > > > > > > So I guess I need to drop from replica 2 + arbiter to replica 1 + > > > arbiter (?). > > > > > > $ gluster volume remove-brick GV2Data replica 1 office-wx-hv1- > > > lab-gfs:/mnt/LogGFSData/brick start > > > Running remove-brick with cluster.force-migration enabled can > > > result in data corruption. It is safer to disable this option so > > > that files that receive writes during migration are not migrated. > > > Files that are not migrated can then be manually copied after the > > > remove-brick commit operation. > > > Do you want to continue with your current cluster.force-migration > > > settings? (y/n) y > > > volume remove-brick start: failed: need 2(xN) bricks for reducing > > > replica count of the volume from 3 to 1 > > > > > > ... What am I missing? > > > > > > - Gilboa > > > _______________________________________________ > > > Users mailing list -- users@ovirt.org > > > To unsubscribe send an email to users-le...@ovirt.org > > > Privacy Statement: https://www.ovirt.org/privacy-policy.html > > > oVirt Code of Conduct: > > > https://www.ovirt.org/community/about/community-guidelines/ > > > List Archives: > > > > > > https://lists.ovirt.org/archives/list/users@ovirt.org/message/OIXTFTJREUAHGP3WUW7DFL3VJNEMFJLF/ > > > > > > _______________________________________________ > > Users mailing list -- users@ovirt.org > > To unsubscribe send an email to users-le...@ovirt.org > > Privacy Statement: https://www.ovirt.org/privacy-policy.html > > oVirt Code of Conduct: > > https://www.ovirt.org/community/about/community-guidelines/ > > List Archives: > > > https://lists.ovirt.org/archives/list/users@ovirt.org/message/MAEPVKYSBBY3ZXO7T3VHVCPLQINDLGFO/
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