Re: vacuumdb causes memory drain.

Sushil Shirodkar wrote:

> > On Thu, Apr 26, 2018 at 10:31 AM, Sushil Shirodkar <sushilps(at)hotmail(dot)com> wrote:
> > > Running "vacuumdb -a -z -v" from the cron on one of our test environment, and
> > > noticed that memory of the server goes down from 3.4GB free to 150MB. Once
> > > the process is over, memory is not released, is it normal or something needs to be
> > > changed ? also other processes start running slow afterwards due to low memory.
> >
> > How are you measuring free memory? Memory might be listed in cached/buffers instead of
> > free but is still available. Although that wouldn't then explain other processes being slow.
>
> I have put some small script which runs in a loop with "free -h" command,
> while I am running "vacuumdb". Once I clear by "sync" or bounce PG,
> everything runs normal afterward.

Then I would say everything is fine.
It is normal for a Linux system to have almost no free memory; the memory is used
for the file system cache.

Do you experience any problems, like reduced performance or high I/O?

Yours,
Laurenz Albe
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