Hi I have linux VM with 2 disks one for OS is sparse the other is for a Database and is Preallocated. When I take a snapshot of the VM both disks change to sparse policy but the disks in the snapshot are 1 sparse and 1 allocated. Before the snapshot the VM was running fine, now it crashes when data is written to the database. When I delete the snapshot the disks go back to 1 sparse and 1 allocated. Has anyone else seen this happen. Ovirt is 4.3.2.1-1.el7 and it is running on a hostedEngine Many thanks Kevin _______________________________________________ Users mailing list -- users(a)ovirt.org To unsubscribe send an email to users-leave(a)ovirt.org Privacy Statement: https://www.ovirt.org/site/privacy-policy/ oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/ List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/OAT5MIMTIZU...

On Thu, Aug 15, 2019 at 10:35 AM Evelina Shames <eshames(a)redhat.com&gt; wrote: > Hey Kevin, > By design, when creating a snapshot, the new volume is created with > 'sparse' allocation policy. > I suggest you to open a bug since this operation should not crash the VM. > Add this description and please add all relevant logs and any relevant > information of your environment. > > Regards, > Evelina > > On Tue, Aug 13, 2019 at 4:10 PM Kevin Doyle <kevin.doyle(a)manchester.ac.uk&gt; > wrote: > >> Hi I have linux VM with 2 disks one for OS is sparse the other is for a >> Database and is Preallocated. When I take a snapshot of the VM both disks >> change to sparse policy but the disks in the snapshot are 1 sparse and 1 >> allocated. Before the snapshot the VM was running fine, now it crashes when >> data is written to the database. When I delete the snapshot the disks go >> back to 1 sparse and 1 allocated. Has anyone else seen this happen. Ovirt >> is 4.3.2.1-1.el7 and it is running on a hostedEngine >> >> Many thanks >> Kevin >> _______________________________________________ >> > Hi, some clarifications needed: what kind of storage are you using? If block based (iSCSI or FC-SAN) I verified problems on sparse allocated disks and databases (Oracle in my case) during high I/O on datafiles.

So, as you did, I used preallocated for data based disks.

For fine tuning of automatic LVM extensions in case of block based storage domains, see also this 2017 thread: https://lists.ovirt.org/archives/list/users@ovirt.org/thread/S3LXEJV3V4CI... not currently using it tohugh with recent versions of oVirt, so I have no "fresh" information about efficiency, depending on I/O load amount HIH anyway, Gianluca _______________________________________________ Users mailing list -- users(a)ovirt.org To unsubscribe send an email to users-leave(a)ovirt.org Privacy Statement: https://www.ovirt.org/site/privacy-policy/ oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/ List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/Q6SKLJQHNYB...