How to check GRUB installation on a specific disk under Linux or Solaris

It’s long time from my last post,
I worked a lot as LPIC traineer , with Redhat Cloud products and I sometimes help my colleagues with Redhat and Solaris patching tasks.

Due to patching tasks I tought about how to check if a specific disk does have GRUB installed?
For what I know there is not any command , so I studied and looking on Internet I found these commands:

Redhat box: ( with /dev/sda as example )
# dd bs=512 count=1 if=/dev/hda | od -Ax -tx1z -v

Solaris box: ( with c0t0d0 as example )
# dd bs=512 count=1 if=/dev/rdsk/c0t0d0s2 | od -c

This is nice!!
I also played on Solaris box with installgrub command , checking the disk before and after the GRUB installation πŸ™‚

Why should I verify this? Because I love to know more as possible I can about any task I do πŸ™‚
Have fun πŸ˜€