My short story of dealing with failed grub2 install which rendered my server unbootable.

It was all good till recent update of grub2. Apparently it no longer fits into MBR and I missed related warnings. Or may be I had grub-legacy. I do not know honestly, but in result I had un-bootable remote server.

Using rescue mode (which is like Live-CD, but instead of GUI gives you SSH access so you could restore your server) I was able to get into server and try to update grub. Here is what I got for grub-install /dev/sda: