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Re: [Xen-users] How can I change "dom0" settings?

Memory is not the only Dom0 setting, but it is probably the most widely used. You can change it and other Dom0 settings from your bootloader's kernel command line. For grub, this is the GRUB_CMDLINE_LINUX[_DEFAULT]= variable in /etc/default/grub. To start Dom0 with 512M memory, set it to
GRUB_CMDLINE_LINUX="... dom0_mem=512M,max:512M"

The max sub-parameter sets the maximum allowable memory that Dom0 can allocate (as opposed to the amount it is initialized with). Setting max equal to dom0_mem effectively disables ballooning for Dom0, and is generally good practice.

There are other parameters for, e.g. limiting the number of vCPUs visible to Dom0, pinning Dom0 to a particular CPU core, and NUMA configuration.

Don't forget to run `grub-mkconfig -o /boot/grub/grub.cfg` or `update-grub` before testing your changes.

You can also change some of these setting at run-time from xl, (e.g. xl mem-set 0 512M), but this causes problems due to the way the kernel allocates memory at startup, as described in the pages below.


Quoting Jason Long <hack3rcon@xxxxxxxxx>:

How can I change "Dom0" settings on my Xen. I guess, I just can change memory setting. Am I right?


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