Hello,
I recently upgraded a VPS that I own which has openSUSE 12.2 64-bit on it from 768MiB of RAM to 1.28GiB, however ‘free’ shows that it only increased from 768MiB to 791MiB. I’ve looked through dmesg and found this:
With the second to last last line being key. If my calculations are correct, 0030800000 in 4k blocks is close to 1.28GiB, but for some reason it’s later only being mapped to 791MiB:
Also, I check my VM control panel which shows 1.29GiB is active. I’ve even completely powered it down and manually started back up at which I saw the memory jump slightly.
Pretty weird.
Since this a VPS, I wonder if your issue has something to do with that…
Just spit-ballin’
Could your VPS be configured for a specific value but also expand to a new value (if needed)?
I suppose I could experiment a little with that in KVM but there’s no way to know if the results would be relevant to whatever VPS technology is being used for your VM. To verify, this might be an interesting Q to ask your Provider.
It turned out to be a VM intricacy: the server must be rebooted (not halted) with the control panel button specifically. No other methods work (probably some script job).