---------- Forwarded message ---------- From: Simon Tian <aixt2006@xxxxxxxxx> Date: 2011/6/13 Subject: Re: snapshot of rbd To: Yehuda Sadeh Weinraub <yehuda.sadeh@xxxxxxxxxxxxx> 2011/6/13 Yehuda Sadeh Weinraub <yehuda.sadeh@xxxxxxxxxxxxx>: > On Sun, Jun 12, 2011 at 7:02 AM, Simon Tian <aixt2006@xxxxxxxxx> wrote: >> >> hi guys, >> >> Â ÂI have some questions about librbd snapshot: >> >> Âint snap_create(const char *snapname); >> Âint snap_remove(const char *snapname); >> Âint snap_rollback(const char *snap_name); >> Âint snap_set(const char *snap_name); >> >> Âint copy(IoCtx& src_io_ctx, const char *srcname, IoCtx& dest_io_ctx, >> const char *destname); >> >> If I create a snapshot S1, and then write 10GB data, and then I want >> to create a snapshot S2. About how long time will the "snap_create" >> take? ÂMay take just several seconds? > > Yes. It updates the header, and sends notifications (through the osd) > to the other clients. >> And how long will it task when remove S2? > > Same as creating it. > > >> How long when rollback to S1? > > Rollback is (currently) is in the order of the number of object of > that image. It needs to go through all the objects and execute an > explicit request of each. For very large images it can be quite long. When a VM is running based on rbd image, and need to rollback to S1. During rollback, seem like that data written by the VM is not allowed? Is there any way to rollback without affecting the user experience of the VM? Thx Simon -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
