>>Just a wild guess - Alexandre, did you tried detect-zeroes blk option >>for mirroring targets?
Hi, yes, I have also tried with detect-zeroes (on or discard) with virtio and virtio-scsi, doesn't help. (I'm not sure that is implemtend in drive-mirror). As workaround currently, after drive-mirror, I doing fstrim inside the guest (with virtio-scsi + discard), and like this I can free space on rbd storage. ----- Mail original ----- De: "Andrey Korolyov" <[email protected]> À: "Fam Zheng" <[email protected]> Cc: "Alexandre DERUMIER" <[email protected]>, "qemu-devel" <[email protected]>, "Ceph Devel" <[email protected]> Envoyé: Samedi 11 Octobre 2014 10:30:40 Objet: Re: [Qemu-devel] qemu drive-mirror to rbd storage : no sparse rbd image On Sat, Oct 11, 2014 at 12:25 PM, Fam Zheng <[email protected]> wrote: > On Sat, 10/11 10:00, Alexandre DERUMIER wrote: >> >>What is the source format? If the zero clusters are actually unallocated >> >>in the >> >>source image, drive-mirror will not write those clusters either. I.e. with >> >>"drive-mirror sync=top", both source and target should have the same >> >>"qemu-img >> >>map" output. >> >> Thanks for your reply, >> >> I had tried drive mirror (sync=full) with >> >> raw file (sparse) -> rbd (no sparse) >> rbd (sparse) -> rbd (no sparse) >> raw file (sparse) -> qcow2 on ext4 (sparse) >> rbd (sparse) -> raw on ext4 (sparse) >> >> Also I see that I have the same problem with target file format on xfs. >> >> raw file (sparse) -> qcow2 on xfs (no sparse) >> rbd (sparse) -> raw on xfs (no sparse) >> > > These don't tell me much. Maybe it's better to show the actual commands and > how > you tell sparse from no sparse? > > Does "qcow2 -> qcow2" work for you on xfs? > >> >> I only have this problem with drive-mirror, qemu-img convert seem to simply >> skip zero blocks. >> >> >> Or maybe this is because I'm using sync=full ? >> >> What is the difference between full and top ? >> >> ""sync": what parts of the disk image should be copied to the destination; >> possibilities include "full" for all the disk, "top" for only the sectors >> allocated in the topmost image". >> >> (what is topmost image ?) > > For "sync=top", only the clusters allocated in the image itself is copied; > for > "full", all those clusters allocated in the image itself, and its backing > image, and it's backing's backing image, ..., are copied. > > The image itself, having a backing image or not, is called the topmost image. > > Fam > -- Just a wild guess - Alexandre, did you tried detect-zeroes blk option for mirroring targets? -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
