| Re: Slow Live Migration (prlctl migrate) [message #53488 is a reply to message #53487] |
Fri, 15 March 2019 10:30   |
khorenko
Messages: 533
Registered: January 2006
Location: Moscow, Russia
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Senior Member |
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Hi,
well, some decrease in network bandwidth utilization is expected:
- on "Copying static data" stage we send a lot of data - disk, memory, big portions => full bandwidth utilization
- on "Live migration stage" we scan disk and memory dirty masks to get data which has been changed while we were coping data on the previous stage.
Once "dirty" data is found, it's sent to the destination => so generally it is lot of small sends and thus bandwidth utilization is less.
Note1: there are many iterations on this stage.
Note2: processes are still running during this stage, so this time is not included into "downtime".
Is it ok if the speed of second stage is only ~180bmit?
Well, i'm not ready to answer this without deep investigation, but as this time is not in the "downtime", hope it's not that important.
And what's your actual whole migration time and downtime? (just approximately, downtime may be measured via "ping CT").
And what size of CT disk and RAM, it does matter surely.
If your problem is solved - please, report it!
It's even more important than reporting the problem itself...
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