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Hi, we are looking at upgrading our 2.7.0 Swift cluster. In the past 
I've modeled this on a dev system by upgrading storage nodes one by one 
(using 2.17 as the target version). This seemed to work well - I 
deliberately left the cluster half upgraded for an extended period to 
test for any cross version weirdness (didn't see any). However I'm 
wanting to check that I have not missed something important. So my 
questions are:

- If upgrading from 2.7.0 is it safe to just grab the latest version 
(e.g 2.23)?

- If not is there a preferred version to jump to first?

- Is it ok for the upgrade to take extended time (e.g weeks) and 
therefore be running with some new and some old storage nodes for that time?

regards

Mark