Implemented support for discarding unused image blocks

[AnotherLife]

Can someone explain this upcoming change please ?

I'm very interested in reducing the size of my exported VMs (.ova), but I'm using a fixed disk.

[mpack]

You obviously can't discard blocks from a fixed size image.

In any case I don't recogize the claim. Can you provide a link?

Edit:  Oh, I see, you are referring to the trim feature of the v4.2 beta. The feature is (as yet) not well documented, but as a command issued by a guest OS I would not expect it to work outside of that context - at least not right away, and never for fixed disks.

[Norchem]

I'm excited to see if this TRIM is passed through the iSCSI to a Solaris ZFS SAN and see if the sparse volume reclaims or zeros out the blocks. This would allow compression or the zvols to shrink their size allocations back down when the guest deletes data. Anyone have any experience with this?