<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Thu, Mar 9, 2017 at 11:39 AM, Nathanaël Blanchet <span dir="ltr"><<a href="mailto:blanchet@abes.fr" target="_blank">blanchet@abes.fr</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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<div class="gmail-m_-1651002033933517188moz-cite-prefix">Le 09/03/2017 à 10:25, Gianluca Cecchi
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<div class="gmail_quote">On Wed, Mar 8, 2017 at 6:05 PM,
Gianluca Cecchi <span dir="ltr"><<a href="mailto:gianluca.cecchi@gmail.com" target="_blank">gianluca.cecchi@gmail.com</a>></span>
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<div>NOTE: during the snapshot creation I see in web
admin console the VM in paused state and also not
responsive in both console and ssh session.</div>
<div>After a couple of seconds it comes back and as
a confirmation I see this in its messages:</div>
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<div>Mar 8 17:38:57 T-ORACLE73 chronyd[616]: System
clock wrong by 19.077230 seconds, adjustment
started<br>
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<div>Is this expected?</div>
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<div class="gmail_extra">Possibly the default changed at some
point in time, so that now it saves memory and so this implies
pause of VM</div>
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Saving memory is essential in some apàplications like DB, so you
won't bypass vm pauses for such a stuff<div><div class="gmail-h5"><br></div></div></div></blockquote><div><br></div><div>Yes, indeed, the important thing is to have an option so that you can set it True or False, depending on the VM you are saving, the application that is running isnide it and the way you want to do backup of the application.</div><div>Nevertheless, RDBMS and also other applications often have some mechanism to be "frozen in a consistent state" so that you can save what you have on disk without need to save memory to have a consistent backup.</div><div>Oracle for example has functionality to be put in "backup mode" where you issue "begin backup" before the snapshot and "end backup" right after snapshot completion.</div><div>I see that POstgreSQL has similar functionality (not tested myself):</div><div><a href="https://www.postgresql.org/docs/9.4/static/continuous-archiving.html#BACKUP-LOWLEVEL-BASE-BACKUP">https://www.postgresql.org/docs/9.4/static/continuous-archiving.html#BACKUP-LOWLEVEL-BASE-BACKUP</a></div><div>and the same for other ones.</div><div><br></div><div>Gianluca </div></div><br></div></div>