Matthew,
Thank you so much for detailed information.
Umair Azam
On 2/11/2014 10:20 AM, Matthew Kaufman wrote:
Hello,
"By default, XenServer automatically tunes the dom0 settings during
installation. IIRC, on a 4G system, ~768MB gets allocated to dom0.
The defaults should work just fine for you.
dom0_mem = 502MB + int(physical_mem * 0.0205)
*Table 2.1. Default Dom0 Memory Size*
Physical Memory
Dom0 Memory
2 GB
543 MB
4 GB
585 MB
8 GB
669 MB
16 GB
837 MB
32 GB
1173 MB
64 GB
1845 MB
128 GB
3188 MB
256 GB
5875 MB
512 GB
11249 MB
1024 GB
21997 MB
2048 GB
43493 MB
Hello,
Citrix Xen related questions should probably be asked on the Citrix Xen
mailing lists :)
Actually; His question is regarding dom0 Sizing WITH His Configuration of
4GB RAM.
So it shouldn't be on Citirx Xen; it applies to CloudStack hardware
builders too or anyone running Apache CloudStack ON physical hardware (I'd
imagine most everybody is here on this mailing list).
By default, XenServer automatically tunes the dom0 settings during
installation.
IIRC, on a 4G system, ~768MB gets allocated to dom0
Here, we use the following sizing computation rules:
Rule:
dom0_mem = 502 + int(physical_mem * 0.0205)
You should always dedicate a fixed amount of RAM for Xen dom0.
This can be done by specifying "dom0_mem=512M,max:512M" option for the Xen
hypervisor (usually xen.gz) in grub.conf/menu.lst. This makes sure that the
initial amount of memory allocated for dom0 is 512 MB (note: Replace this
value with the amount of memory you want to allocate to dom0) and leaves
the rest of the host system's RAM available for other guests. See this
grub.conf example for GRUB1:
*Table 2.1. Default Dom0 Memory Size*
Physical Memory
Dom0 Memory
2 GB
543 MB
4 GB
585 MB
8 GB
669 MB
16 GB
837 MB
32 GB
1173 MB
64 GB
1845 MB
128 GB
3188 MB
256 GB
5875 MB
512 GB
11249 MB
1024 GB
21997 MB
2048 GB
43493 MB
http://wiki.xen.org/wiki/Xen_Best_Practices#Xen_dom0_dedicated_memory_and_preventing_dom0_memory_ballooning
