Request: Livemigration improvements #1520

FlorianHeigl opened this Issue Oct 20, 2013 · 5 comments


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I'll drop this here since I now spend quite some time to find it's all hardcoded in the xe binary.

  • would like to configure a interface (bonded or not) for live migrations (sanity, proper configuration, monitoring)
  • would like to configure to not use stunnel or any ssl (performance/latency impact is massive)
  • would like to really configure compression algorithm, ideally turn it off or at least use something modern and multithreaded (performance/latency impact is massive)
  • at least!!!! switch to lightest gzip mode (throughput impact is massive, default level 6 is 4-6 times slower than level 1)

Forcing to use stunnel + gzip has made the Xen live migration slower than it even was in 2006, on 2006's hardware.

  • Documentation would be cool, too. i.e. XE_STUNNEL env var could be a workaround, just it's not documented anywhere, so one would be stupid using it.
  • If able to configure a dedicated interface and port, ssl disabled, compression disabled, infiniband users could use SDP for the migration, meaning 20x+ performance increase over GigE

If you can only do one thing, go for gzip -1
If you can only do two things, go for gzip -1 and documentation.


djs55 commented Oct 20, 2013

Thanks for the input.

FWIW there used to be an encryption option for migration, added in commit 5c9edd2 but then removed again in 7fcc90f (while storage motion was going in). Although encryption defaulting to on sounds like a safe default, I agree it should be possible to turn it off. I'm looking into a similar mechanism for cross-host VDI.copy.


It would be really nice if storagexenmotion would work offline too. I find myself a lot of times in the situations when I moved a vm live from an older server to a newer one and then I can't move it back because of CPU flags. I understand that live it would not be possible but maybe it can be done offline?

I posted here because seemed to be in the same spectra "Livemigration improvements"

Thank you

Would be nice, also if this ticket, that affects EVERY USER of livemigration, would see some consideration.


simonjbeaumont commented Dec 8, 2015

@georgyous this has been done now: #2228

I wonder If I should bring out candles for this requests' 3rd birthday at some point.

I see quite a few people moving to other solutions last year... and I'll say I'm not surprised if even a suggestion along the lines "make everything faster for everyone" doesn't even get a review (nor did it during original implementation).

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