2.3 Changing the Dom0 Memory Size

When you install Oracle VM Server, the installer sets a default memory size for Dom0. The algorithm used is:

dom0_mem = 502 + int(physical_mem * 0.0205)

Example sizes are set out in table Table 2.1.

Table 2.1 Default Dom0 Memory Size

Physical Memory

Dom0 Memory

2 GB

560 MB

4 GB

600 MB

8 GB

680 MB

16 GB

848 MB

32 GB

1184 MB

64 GB

1856 MB

128 GB

4000 MB

256 GB

5888 MB

512 GB

11264 MB

1024 GB

22008 MB

2048 GB

43504 MB

You may encounter performance issues if the dom0 memory size is not set appropriately for your needs on the Oracle VM Server.

To change the Dom0 memory allocation, edit the /boot/grub/grub.conf file on the Oracle VM Server and change the dom0_mem parameter, for example, to change the memory allocation to 1024 MB, edit the file to be:

kernel /xen.gz console=com1,vga com1=38400,8n1 dom0_mem=1024M