ivm & memory &hang swap

[Carme Torca]

Hi,

I have some hp ivm with virtual machines.

I have one problem with the swap, when one server begins to swap all the other ivm go slow, slow, slow...
The configuration is this:

server        hpvm        vcpus    memory    swap
hivihid1
         hejcswi0    4    8Gb    8Gb

         hejcswi2    4    8Gb    8Gb
 
                hejcdoi0    4    16Gb    4Gb

The server hivihid1 has only one disc and its has 8Gb swap.
The other ivm are lvs of this disc.


I would like to known if the configuration its correct.

server: 8Gb swap

hivihid1:/>swapinfo -tam
             Mb      Mb      Mb   PCT  START/      Mb
TYPE      AVAIL    USED    FREE  USED   LIMIT RESERVE  PRI  NAME
dev        8192       0    8192    0%       0       -    1  /dev/vg00/lvol2
reserve       -    2017   -2017
memory    46652   39970    6682   86%
total     54844   41987   12857   77%       -       0    -



8 de memoria and 8 de swap

root@hejcswi0:/>swapinfo -tam
             Mb      Mb      Mb   PCT  START/      Mb
TYPE      AVAIL    USED    FREE  USED   LIMIT RESERVE  PRI  NAME
dev        4096    2976    1120   73%       0       -    1  /dev/vg00/lvol2
dev        4096    2967    1129   72%       0       -    1  /dev/vg00/lvswap
reserve       -    1794   -1794
memory     7787    3555    4232   46%
total     15979   11292    4687   71%       -       0    -

8 de memoria and 8 de swap

hejcswi2:/>swapinfo -tam
             Mb      Mb      Mb   PCT  START/      Mb
TYPE      AVAIL    USED    FREE  USED   LIMIT RESERVE  PRI  NAME
dev        4096    1622    2474   40%       0       -    1  /dev/vg00/lvol2
dev        4096    1618    2478   40%       0       -    1  /dev/vg00/lvswap
reserve       -    2691   -2691
memory     7787    3671    4116   47%
total     15979    9602    6377   60%       -       0    -

16 Gb Memoria and  4 de swap

hejcdoi0# swapinfo -tam
             Mb      Mb      Mb   PCT  START/      Mb
TYPE      AVAIL    USED    FREE  USED   LIMIT RESERVE  PRI  NAME
dev        4096       0    4096    0%       0       -    1  /dev/vg00/lvol2
reserve       -     308    -308
memory    15579    2294   13285   15%
total     19675    2602   17073   13%       -       0    -


 
Could anyone help me?

Thanks a lot of,

Carme.

[Patrick Wallek · Accepted solution]

If you have a single disk on your iVM host and then logical volumes off of that disk for your IVM guest servers, then I am not surprised that you are having performance trouble when one of your IVMs starts paging out.

You have to remember that when you start paging out that will generate a LOT of I/O.  Since you only have 1 disk for, essentially, 4 systems all of that I/O from one system will definitely affect all of the other systems.

It sounds to me like you need more disks on this system for your IVM guests to spread out the I/O load, especially if you are not going to give more memory to the guest that is paging.