Re: [libvirt] Question about fsfreeze/fsthaw API

On 11/06/2013 05:31 PM, Tomoki Sekiyama wrote: > Hi all, > > Is there any plans to add APIs to execute fsfreeze/fsthaw in qemu guests? > (something like virDomainFSFreeze(domain,timeout,flags) and > virDomainFSThaw(domain,timeout,flags)) I'm wondering if it might be better to have a single command with a callback argument, something like: virDomainQuiese(domain, timeout, callback, opaque, flags) which calls callback(domain, opaque) at the right point in time. I'm just a bit worried that since the freeze/thaw sequence is already handled as a pair by the QUIESCE flag of snapshot creation that exposing it as two non-atomic APIs may lead to inconsistent states that we'd have a hard time tracking which commands are allowed in which state. With only a single command and a callback, we have guaranteed semantics that all other API are locked out by our normal job mechanism, and that we can pair the freeze/thaw under the hood just as we do in snapshots.