Date: Fri, 22 Jan 2021 15:53:50 +0200 From: Mihai Carabas <mihai.carabas@gmail.com> To: Matt Churchyard <matt.churchyard@userve.net> Cc: Elena Mihailescu <elenamihailescu22@gmail.com>, "freebsd-virtualization@freebsd.org" <freebsd-virtualization@freebsd.org> Subject: Re: Warm Migration feature for bhyve - review on Phabricator Message-ID: <CANg1yUtTg_A7BrjWQLqeaUd4XrKVS0WzqdfrK1i3ZjXiQ8TmCw@mail.gmail.com> In-Reply-To: <e9a65e1ad4e0491083820fbb03d873e8@SERVER.ad.usd-group.com> References: <CAGOCPLhP3i4hPcKHX=RrKFbQiSenjtJrvzTx%2BARnP8=QN%2BzmqQ@mail.gmail.com> <e9a65e1ad4e0491083820fbb03d873e8@SERVER.ad.usd-group.com>
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Hello Matt, Thank you for your input. The Warm/Live Migration feature is designated for cloud and cluster environments. Storage Live Migration is a feature that would be nice to have, but will be tackled after we get in warm migration and live migration using a shared storage. The code base is big enough as it is. Adding storage migration will make it hard to get in. Also this is the track that was followed by all hypervisors until now (KVM, Hyper-V, VMware). Thanks, Mihai On Fri, Jan 22, 2021 at 12:10 PM Matt Churchyard <matt.churchyard@userve.net> wrote: > > Hello, all, > > > We have recently opened a review on Phabricator for the warm migration > code for > bhyve [1]. Please take a look and let us know if it is anything > we can improve. > > > [1] https://reviews.freebsd.org/D28270 > > > Thank you, > > Elena > > I appreciate that this isn't really related to the current review, and > commend the work being put into bhyve - it's an invaluable addition to > FreeBSD. I'm just wondering if any thought has been put into the future > possibility for transfer of disk data during migration (i.e. the equivalent > of "storage vmotion") > > The current process (from a mile high overview) effectively seems to be > the following - > > * Start guest on host2 pointing at a shared disk, and halt any execution > * use bhyvectl to pause and begin migration on host1 > * Start the guest on host2 > > What would be the feasibility of being able to run a process such as the > following? Obviously it would likely need to be orchestrated by an external > tool, but to me it seems the main requirement is really just to be able to > provide separate control over the pause and migrate steps on host1 - > > * send a ZFS snapshot of the running machine to host2 > * start the guest in migrate recv mode on host2 > * pause the guest on host1 > * send a new snapshot > * initiate the migration of memory/device data > * start guest on host2 > > Are there any major complications here I'm not aware of other than the > requirement to pause the guest and kick off the state migration as two > separate calls? > > Shared storage is great but becomes complex and expensive if you want high > performance and reliability (seeing as the storage quickly becomes a major > single point of failure without enterprise active/active kit). I suspect > the most common deployment of bhyve is independent hosts with local ZFS > pools as this is easy/cheap and gives great performance. Most hypervisors > only had "shared storage" migration for a long time but the big ones now > also support transferring disk data live. It would be great to be able to > do this out of the gate. > > I did have a poor mans version of this in vm-bhyve, but obviously relied > on stopping and restarting the guest. I always had problems with the nc > commands not exiting cleanly though and hanging the process so never made > it official. > > Regards, > Matt > > _______________________________________________ > freebsd-virtualization@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-virtualization > To unsubscribe, send any mail to " > freebsd-virtualization-unsubscribe@freebsd.org" > _______________________________________________ > freebsd-virtualization@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-virtualization > To unsubscribe, send any mail to " > freebsd-virtualization-unsubscribe@freebsd.org" >
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