pitter patter on the keyboard

GRUB2 is highly customizable and feature-rich, however it is a bit of a nightmare if you configure bootloaders regularly. Unfortunately GRUB 0.97 doesn’t support ext4 and – if you were an idiot like me – you might have set up your new dedicated with an ext4 /boot. Now, you have neither the time nor patience to re-install and need to make Xen go.

First, copy your Dom0 .config and kernel to /boot/. /etc/grub.d/20_linux_xen picks up on the CONFIG_XEN_PRIVILEGED_GUEST=y variable.

# cp /usr/src/linux/arch/x86_64/boot/bzImage /boot/kernel-dom0
# cp /usr/src/linux/.config /boot/config-dom0

Next, remove the executable flag from /etc/grub.d/10_linux or you will end up with three or four entries that boot straight to the Dom0 kernel without the hypervisor.

# chmod -x /etc/grub.d/10_linux

To add kernel boot parameters to your grub.cfg (as generated with grub2-mkconfig and 20_linux_xen) add these lines to your /etc/default/grub file:

GRUB_CMDLINE_LINUX_XEN_REPLACE="max_loop=128"
GRUB_CMDLINE_XEN="dom0_mem=512"

The former will place your boot options on the Dom0 kernel’s module line. The latter will place boot options on the xen.gz hypervisor’s kernel line.

Now, generate your new configuration:

# grub2-mkconfig -o /boot/grub2/grub.cfg

Once the config file has been written, determine the position of the Xen hypervisor entry and update GRUB_DEFAULT in /etc/default/grub.

Install GRUB2 to your MBR(s) as necessary:

# grub2-install /dev/sda 

Chances are you just changed the port settings in framework/base/config/ofbiz-containers.xml but forgot to update framework/service/config/serviceengine.xml.

Open serviceengine.xml and replace all four instances of “8080″ with the non-secure port you specified in ofbiz-containers.xml.

If you don’t keep your php.ini in sync with your PHP version you might be wondering why very large forms seem to be missing their bottom half when you go to analyse your $_POST array. Newer releases of PHP have a configuration directive called max_input_fields with a default value of 1000 which is meant to help reduce the risk of DoS.

I’ve seen it argued that forms with over 1000 fields can probably be organised a better way, and that’s mostly true – but what happens when your software is a dynamically generated spreadsheet a la CSV verification and pre-processing?

You might want to take this as a cue to update your php.ini but it’s also safe to drop

max_input_fields = 40960

or some other number reasonably tuned to your needs into your existing config.