Xen Bug: xen_net: Memory squeeze in netback driver (32bit PAE)

If you are receiving the following error in your logs while running a 32bit PAE Xen Kernel:

xen_net: Memory squeeze in netback driver

Then you need to do the following:

1. In your grub.conf (or other bootloader) set the Dom0 to a fixed size: dom0_mem=1024.

2. In /etc/xen/xend-config.sxp set dom0-min-mem to the same size as above.

3. Reboot

Basically what you are doing is ensuring that Dom0 will not be decreased in size, as when this happens it causes problems the the xen_net driver which can in turn cause network connectivity problems with your DomUs.

Filed under: Uncategorized by — aaron @ 10:10 pm

Upgrading DomU Kernel HyperVM/Xen

First install both the Dom0 and DomU kernel by doing a yum upgrade.  Once you have done this, reboot the server into the new Dom0 kernel and run the following command (before you start each VPS on the server):

cd /usr/local/lxlabs/hypervm/httpdocs/; lphp.exe ../bin/misc/fixcentos5xen.php

Filed under: Uncategorized by — aaron @ 9:42 pm