In this tutorial, I will explain how to replace the drbd backend devices (for data and metadata) without destroying the information. Actually, during this process, the information will be safely kept on the other node.
This should be done in case of one node's disk failure or if you simply just want to move the date to other disk.
For this you will have to download the needed packages from IBM website. They are not free to download and you need user/pass and license. I will not cover this part at all.
Assuming you have already the needed packages, read what follows:
If you attach to linux box a disk partitioned under FreeBSD or OS X, you will find this warning message on fdisk command:
"WARNING: GPT (GUID Partition Table) detected on '/dev/sdc'! The util fdisk doesn't support GPT. Use GNU Parted."
During mksysb process you have the chance to encounter many errors. One of them is "An internal packing error occurred: incorrect size" and I will try below to aid you to get pass it.
# mksysb -eiX /backups-tmp/gzlpar-rootvg.sysb
Creating information file (/image.data) for rootvg.
Creating list of files to back up
Backing up 89961 files......................[color=red]An internal packing error occurred: incorrect size
./var/adm/wtmp will not be backed up.[/color]
Debian is great but sometimes basic simple things are missing so we have to step in.
For example, Debian is coming by default with /etc/rc.local where you can put your custom commands which are automatically executed on startup. But what about custom stop script to be executed on shutdown or reboot? This is missing.
No problem! All you can do is follow the instructions below.
1. Edit or replace /etc/init.d/rc.local with this one:
root@pluto:~# cat /etc/init.d/rc.local
### BEGIN INIT INFO
# Provides: rc.local
Before starting, I have to mention this tutorial is not about ZFS Fuse which comes by default with Debian. This is the real deal, the native ZFS for Linux, without fuse support. In theory should be faster and more reliable and according to my tests so far, it is amazing!