On Thu, Dec 10, 2015 at 12:24 PM, Michal Skrivanek <mskrivan@redhat.com> wrote:


>
> Yes, CentOS 7.1 updated up to a couple of days ago.

Can you try 7.2? I don’t remember exactly but it may be that in earlier guests it’s not automatic. Check some tips for onlining memory explicitly

5.2. How to online memory
 ------------
Even if the memory is hot-added, it is not at ready-to-use state.
For using newly added memory, you have to "online" the memory block.

For onlining, you have to write "online" to the memory block's state file as:

% echo online > /sys/devices/system/memory/memoryXXX/state

 

Hello,
with your suggestions it worked as expected, without updating any packages in VM 7.1 guest (I seemed to remember that the forced online operation should not be necessary any more...):

Starting state with 10Gb of ram inside the VM
[root@racclient1 ~]# ll -d  /sys/devices/system/memory/memory* | wc -l
80

slots defined:
0 --> 23
32 --> 87

Increase from web gui memory from 10240 to 12288

I see this in messages as expected

Dec 10 12:59:32 racclient1 kernel: init_memory_mapping: [mem 0x2c0000000-0x33fffffff]

In /sys/devices/system/memory I see 16 new memoryxx directories (probably each one addressing 128Mb...)

88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103

They have indeed been added but are offline, eg

latest previous one:
[root@racclient1 ~]# cat /sys/devices/system/memory/memory87/state 
online

first newly added one:
[root@racclient1 ~]# cat /sys/devices/system/memory/memory88/state 
offline

[root@racclient1 ~]# cat /sys/devices/system/memory/memory87/online 
1
[root@racclient1 ~]# cat /sys/devices/system/memory/memory88/online 
0

put online the new segments:
[root@racclient1 ~]# for i in $(seq 88 103)
> do
> echo online > /sys/devices/system/memory/memory${i}/state
> done

Memory has been increased now, also from inside the OS.

[root@racclient1 ~]# free
              total        used        free      shared  buff/cache   available
Mem:       12334428      222080    11934044        8480      178304    12019544


NOTE: no new entries after online memory, neither in messages file nor in dmesg output.

Questions:
1) which component to bugzilla against for message confusing window of the gui?
2) Initially I see that my VM (in webadmin gui) has 8Gb of defined memory AND 8Gb of "Physical Memory Guaranteed".
After increasing memory, the second one remains the same and doesn't change even after shutdown / Power on.
I think it could be an enhancement to ask the user if he/she wants to change it too, instead of manually go through 
Edit --> resource allocation --> memory allocation screen
If seen as a agreed enhancement, which components to bugzilla against for RFE?
Gianluca