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Re: Gluster VM image Resync Time
by Strahil 28 Mar '19

28 Mar '19

Hi Krutika, I have noticed some performance penalties (10%-15%) when using sharing in v3.12 . What is the situation now with 5.5 ? Best Regards, Strahil NikolovOn Mar 28, 2019 08:56, Krutika Dhananjay <kdhananj(a)redhat.com> wrote: > > Right. So Gluster stores what are called "indices" for each modified file (or shard) > under a special hidden directory of the "good" bricks at $BRICK_PATH/.glusterfs/indices/xattrop. > When the offline brick comes back up, the file corresponding to each index is healed, and then the index deleted > to mark the fact that the file has been healed. > > You can try this and see it for yourself. Just create a 1x3 plain replicate volume, and enable shard on it. > Create a big file (big enough to have multiple shards). Check that the shards are created under $BRICK_PATH/.shard. > Now kill a brick. Modify a small portion of the file. Hit `ls` on $BRICK_PATH/.glusterfs/indices/xattrop of the online bricks. > You'll notice there will be entries named after the gfid (unique identifier in gluster for each file) of the shards. > And only for those shards that the write modified, and not ALL shards of this really big file. > And then when you bring the brick back up using `gluster volume start $VOL force`, the > shards get healed and the directory eventually becomes empty. > > -Krutika > > > On Thu, Mar 28, 2019 at 12:14 PM Indivar Nair <indivar.nair(a)techterra.in> wrote: >> >> Hi Krutika, >> >> So how does the Gluster node know which shards were modified after it went down? >> Do the other Gluster nodes keep track of it? >> >> Regards, >> >> >> Indivar Nair >> >> >> On Thu, Mar 28, 2019 at 9:45 AM Krutika Dhananjay <kdhananj(a)redhat.com> wrote: >>> >>> Each shard is a separate file of size equal to value of "features.shard-block-size". >>> So when a brick/node was down, only those shards belonging to the VM that were modified will be sync'd later when the brick's back up. >>> Does that answer your question? >>> >>> -Krutika >>> >>> On Wed, Mar 27, 2019 at 7:48 PM Sahina Bose <sabose(a)redhat.com> wrote: >>>> >>>> On Wed, Mar 27, 2019 at 7:40 PM Indivar Nair <indivar.nair(a)techterra.in> wrote: >>>> > >>>> > Hi Strahil, >>>> > >>>> > Ok. Looks like sharding should make the resyncs faster. >>>> > >>>> > I searched for more info on it, but couldn't find much. >>>> > I believe it will still have to compare each shard to determine whether there are any changes that need to be replicated. >>>> > Am I right? >>>> >>>> +Krutika Dhananjay >>>> > >>>> > Regards, >>>> > >>>> > Indivar Nair >>>> > >>>> > >>>> > >>>> > On Wed, Mar 27, 2019 at 4:34 PM Strahil <hunter86_bg(a)yahoo.com> wrote: >>>> >> >>>> >> By default ovirt uses 'sharding' which splits the files into logical chunks. This greatly reduces healing time, as VM's disk is not always completely overwritten and only the shards that are different will be healed. >>>> >> >>>> >> Maybe you should change the default shard size. >>>> >> >>>> >> Best Regards, >>>> >> Strahil Nikolov >>>> >> >>>> >> On Mar 27, 2019 08:24, Indivar Nair <indivar.nair(a)techterra.in> wrote: >>>> >> >>>> >> Hi All, >>>> >> >>>> >> We are planning a 2 + 1 arbitrated mirrored Gluster setup. >>>> >> We would have around 50 - 60 VMs, with an average 500GB disk size. >>>> >> >>>> >> Now in case one of the Gluster Nodes go completely out of sync, roughly, how long would it take to resync? (as per your experience) >>>> >> Will it impact the working of VMs in any way? >>>> >> Is there anything to be taken care of, in advance, to prepare for such a situation? >>>> >> >>>> >> Regards, >>>> >> >>>> >> >>>> >> Indivar Nair >>>> >> >>>> > ______________

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Re: ovirt data domain with multi luns, any best practice
by Strahil 28 Mar '19

28 Mar '19

In my opinion it's best to have 2 data domains. Best Regards, Strahil NikolovOn Mar 28, 2019 05:32, adam_xu(a)adagene.com.cn wrote: > > Hello, everyone. I had a question on how to create a data domain in the best way. > for example, I have a FCP device and there's a lot of hdds and ssds in that device. I ceate 2 luns. one consisting of HDDs and the other consisting of SSDs. I want to make some normal vms run in the lun with hdd and some vms (such as DB) run in the lun with ssd. > so, shoud I create one data domain with the 2 luns. or shoud I create 2 difference data domains, and every data domain with a single lun in it? > thanks. > ________________________________ > yours Adam

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ovirt data domain with multi luns, any best practice
by adam_xu＠adagene.com.cn 28 Mar '19

28 Mar '19

Hello, everyone. I had a question on how to create a data domain in the best way. for example, I have a FCP device and there's a lot of hdds and ssds in that device. I ceate 2 luns. one consisting of HDDs and the other consisting of SSDs. I want to make some normal vms run in the lun with hdd and some vms (such as DB) run in the lun with ssd. so, shoud I create one data domain with the 2 luns. or shoud I create 2 difference data domains, and every data domain with a single lun in it? thanks. yours Adam

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User permissions needed to clone template disk
by Wood Peter 27 Mar '19

27 Mar '19

Hi, Users have PowerUserRole permissions on the cluster and the storage objects. Also TemplateCreator role on the Datacenter. When users create VMs from templates there is no option to clone the disk and create independent VM disk. The resource allocation section is not visible at all. What permissions should I give users so they can clone the disk when creating a VM from a template? Using oVirt 4.2.8.2-1.el7 Thank you, -- Peter

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Bad Volume Specification
by Bryan Sockel 27 Mar '19

27 Mar '19

Having an issue with starting one of my VM's. Looks like there was a problem with an auto generated snapshot on the VM. The snapshot file is missing: VDSM-Tool Output: image: 52f31c3a-25ac-4930-8e67-105945dd42b5 - 461e1747-3a59-4abc-ac6a-2013ec7858d3 status: OK, voltype: INTERNAL, format: RAW, legality: LEGAL, type: PREALLOCATED, capacity: 53687091200, truesize: 53687091200 - fe5fb4a4-8b3a-4bad-8f03-9dd179ac8397 status: OK, voltype: INTERNAL, format: COW, legality: LEGAL, type: SPARSE, capacity: 53687091200, truesize: 6576668672 - a01d662f-cf33-4c86-b0ba-8bddc6d25dfd status: ILLEGAL, voltype: LEAF, format: COW, legality: ILLEGAL, type: SPARSE, capacity: 53687091200, truesize: 3221225472 lvs -o+lv_tags |grep 52f31c3a-25ac-4930-8e67-105945dd42b5 Couldn't find device with uuid 5UNXpR-SmSR-KqA2-swpe-kcQi-X7tt-7B5wRz. 461e1747-3a59-4abc-ac6a-2013ec7858d3 8dfaac42-32fc-4e23-b5cb-e5c2c3c56c9d -wi-a----- 50.00g IU_52f31c3a-25ac-4930-8e67-105945dd42b5,MD_43,PU_00000000-0000-0000-0000-000000000000 a01d662f-cf33-4c86-b0ba-8bddc6d25dfd 8dfaac42-32fc-4e23-b5cb-e5c2c3c56c9d -wi------- 3.00g IU_52f31c3a-25ac-4930-8e67-105945dd42b5,MD_46,PU_fe5fb4a4-8b3a-4bad-8f03-9dd179ac8397 fe5fb4a4-8b3a-4bad-8f03-9dd179ac8397 8dfaac42-32fc-4e23-b5cb-e5c2c3c56c9d -wi-a----- 6.12g IU_52f31c3a-25ac-4930-8e67-105945dd42b5,MD_45,PU_461e1747-3a59-4abc-ac6a-2013ec7858d3 qemu-img info /dev/8dfaac42-32fc-4e23-b5cb-e5c2c3c56c9d/a01d662f-cf33-4c86-b0ba-8bddc6d25dfd qemu-img: Could not open '/dev/8dfaac42-32fc-4e23-b5cb-e5c2c3c56c9d/a01d662f-cf33-4c86-b0ba-8bddc6d25dfd': Could not open '/dev/8dfaac42-32fc-4e23-b5cb-e5c2c3c56c9d/a01d662f-cf33-4c86-b0ba-8bddc6d25dfd': No such file or directory What is the best way to remove the snapshot from the vm (PSQL statement to delete the entry from the database)? Thank You, Bryan Sockel

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VM disk corruption with LSM on Gluster
by Sander Hoentjen 27 Mar '19

27 Mar '19

Hello, tl;dr We have disk corruption when doing live storage migration on oVirt 4.2 with gluster 3.12.15. Any idea why? We have a 3-node oVirt cluster that is both compute and gluster-storage. The manager runs on separate hardware. We are running out of space on this volume, so we added another Gluster volume that is bigger, put a storage domain on it and then we migrated VM's to it with LSM. After some time, we noticed that (some of) the migrated VM's had corrupted filesystems. After moving everything back with export-import to the old domain where possible, and recovering from backups where needed we set off to investigate this issue. We are now at the point where we can reproduce this issue within a day. What we have found so far: 1) The corruption occurs at the very end of the replication step, most probably between START and FINISH of diskReplicateFinish, before the START merge step 2) In the corrupted VM, at some place where data should be, this data is replaced by zero's. This can be file-contents or a directory-structure or whatever. 3) The source gluster volume has different settings then the destination (Mostly because the defaults were different at creation time): Setting old(src) new(dst) cluster.op-version 30800 30800 (the same) cluster.max-op-version 31202 31202 (the same) cluster.metadata-self-heal off on cluster.data-self-heal off on cluster.entry-self-heal off on performance.low-prio-threads 16 32 performance.strict-o-direct off on network.ping-timeout 42 30 network.remote-dio enable off transport.address-family - inet performance.stat-prefetch off on features.shard-block-size 512MB 64MB cluster.shd-max-threads 1 8 cluster.shd-wait-qlength 1024 10000 cluster.locking-scheme full granular cluster.granular-entry-heal no enable 4) To test, we migrate some VM's back and forth. The corruption does not occur every time. To this point it only occurs from old to new, but we don't have enough data-points to be sure about that. Anybody an idea what is causing the corruption? Is this the best list to ask, or should I ask on a Gluster list? I am not sure if this is oVirt specific or Gluster specific though. Kind regards, Sander Hoentjen

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Thin clients connect to a virtual machine using spice and require a password
by xilazz＠126.com 27 Mar '19

27 Mar '19

Hello everyone, when I want to use the thin client to connect the virtual machine, I will use spice mode to connect, but I need to specify the port of the host and spice password. Could you please tell me where I can check the spice password of the virtual machine

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ETL DWH errors after restoring to a new server
by Staniforth, Paul 27 Mar '19

27 Mar '19

Hello, I have deployed a new machine to run our engine 4.2.8 using engine-backup to do a full backup/restore to a clean Centos install. We are now having a lot of errors with ovirt-engine-dwhd e.g. java.lang.OutOfMemoryError: Java heap space java.lang.OutOfMemoryError: GC overhead limit exceeded org.postgresql.util.PSQLException: An I/O error occured while sending to the backend. We had a file from 2015 /etc/ovirt-engine/engine.conf.d/10-setup-java.conf ENGINE_HEAP_MIN="5845M" ENGINE_HEAP_MAX="5845M" I changed it to ENGINE_HEAP_MIN=2g ENGINE_HEAP_MAX=4g and restarted the engine and dwhd But am still getting errors. Regards, Paul S. To view the terms under which this email is distributed, please go to:- http://leedsbeckett.ac.uk/disclaimer/email/

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Gluster VM image Resync Time
by Indivar Nair 27 Mar '19

27 Mar '19

Hi All, We are planning a 2 + 1 arbitrated mirrored Gluster setup. We would have around 50 - 60 VMs, with an average 500GB disk size. Now in case one of the Gluster Nodes go completely out of sync, roughly, how long would it take to resync? (as per your experience) Will it impact the working of VMs in any way? Is there anything to be taken care of, in advance, to prepare for such a situation? Regards, Indivar Nair

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oVirt Roles and Permissions
by Wood Peter 27 Mar '19

27 Mar '19

Hi, I'm trying to setup oVirt 4.2.8.2-1.el7 based on a few simple requirements: Users should be able to: 1) reate new VMs 2) create VMs from templates 2a) Ability to clone the template disk to create a VM independent of the template 3) create templates 4) view only the VMs they have permissions to work with i.e. UserVmManager role assign to them This was all possible through the "User Portal" in version 3 (3.6 is what I had). The new "VM Portal" doesn't allow users to create templates. In order to satisfy (3) users must login to the Admin Portal. This is OK but I created a new Admin role with just login permissions and users can see all VMs in the cluster. I assume a filter can be created but in general I don't want them to have that much visibility. I can probably get away without (3) but I still can figure out how to do (2a) using "VM Portal". All VMs created from a template are dependent on that template. Even if the template is optimized for Server. How do I accomplish this? Thank you in advance for any suggestions. -- Peter

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