On Wed, Jun 15, 2022 at 3:21 PM Frank Schilder <frans@xxxxxx> wrote: > > Hi Eugen, > > in essence I would like the property "thick provisioned" to be sticky after creation and apply to any other operation that would be affected. > > To answer the use-case question: this is a disk image on a pool designed for predictable high-performance. On images on this pool we need to avoid any latency spikes due to on-demand allocation of non-provisioned objects. It is kind of strange that the rbd cli API is incomplete with regard to the thick provision property. Hi Frank, Yeah, it appears to be an omission. I filed [1] to get that addressed one day. RBD "thick provisioning" is a bit of odd ball feature. There are other issues with it: bluestore compression, if enabled, would interfere with it, for example. In general, the "thickness" (really just a bunch of zeroes written to the image on your behalf) isn't safe-guarded against any kind of compression-like optimization on the backend. > > I'm not sure if a flatten will have the desired effect. It just merges all snapshots, which does not require to allocate unallocated objects if they are not present in any snapshot. An un-sparsify image would do that. Did anyone find a reasonable work-around except maybe a dd after the end of the existing objects? Or a dd of the disk image onto itself? "dd if=/dev/zero bs=<object size> ..." for the grown area is a perfectly fine workaround. [1] https://tracker.ceph.com/issues/56064 Thanks, Ilya > > Best regards, > ================= > Frank Schilder > AIT Risø Campus > Bygning 109, rum S14 > > ________________________________________ > From: Eugen Block <eblock@xxxxxx> > Sent: 15 June 2022 14:54:54 > To: ceph-users@xxxxxxx > Subject: Re: rbd resize thick provisioned image > > So basically, you need the reverse sparsify command, right? ;-) > I only find several mailing list thready asking why someone would want > thick-provisioning but it happened eventually. I suppose cloning and > flattening the resulting image is not a desirable workaround. > > > Zitat von Frank Schilder <frans@xxxxxx>: > > > Hi all, > > > > I need to increase the size of images created with > > --thick-provision. Using resize will just change the provisioned > > size, but not allocate/initialize the additional space. I seem to be > > unable to find an option that will maintain thick provisioning of an > > image when resizing. > > > > Is there a way to resize thick provisioned images properly, that is, > > maintaining thick provisioning? > > > > Thanks and best regards, > > ================= > > Frank Schilder > > AIT Risø Campus > > Bygning 109, rum S14 > > _______________________________________________ > > ceph-users mailing list -- ceph-users@xxxxxxx > > To unsubscribe send an email to ceph-users-leave@xxxxxxx > > > > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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