Re: [ovirt-users] effectiveness of "discard=unmap"

Am 2018-02-12 um 13:40 schrieb Idan Shaby: On Mon, Feb 12, 2018 at 1:55 PM, Matthias Leopold > wrote: Hi Idan, thanks for your answer. But i'm still confused, because i thought that the content of

Re: [ovirt-users] effectiveness of "discard=unmap"

On Mon, Feb 12, 2018 at 1:55 PM, Matthias Leopold < matthias.leop...@meduniwien.ac.at> wrote: > Hi Idan, > > thanks for your answer. But i'm still confused, because i thought that the > content of /sys/block/dm-X/queue/discard* in the VM OS should depend on the > setting of the

Re: [ovirt-users] effectiveness of "discard=unmap"

Hi Matthias, When the guest executes a discard call of any variation (fstrim, blkdiscard, etc.), the underlying thinly provisioned LUN is the one that changes - it returns the unused blocks to the storage array and gets smaller. Therefore, no change is visible to the guest OS. If you want to

[ovirt-users] effectiveness of "discard=unmap"

Hi, i'm sorry to bother you again with my ignorance of the DISCARD feature for block devices in general. after finding several ways to enable "discard=unmap" for oVirt disks (via standard GUI option for iSCSI disks or via "diskunmap" custom property for Cinder disks) i wanted to check in