Re: Debian, Xen and DRBD: Enabling true server redundancy

[Helmut Wollmersdorfer <helmut.wollmersdorfer@gmx.at>]

Tom Hibbert wrote:

> # modprobe drbd

> Note that drbd can only be configured as a module (for reasons
> unfathomable to me).

Some people compile it into the kernel, which should work.
If not with a XENized one, maybe somebody on the drdb-lists has a solution.

> The builtin drbddisk resource handler had some problems, so I modified
> it slightly.

If you report this to the developers of DRBD, this would be fine.

> Please give me some feedback on this documentation style. 

First, great thanks for your doc.

Some people do not like this 'on my $distro I did' style.

IMHO it is very valuable for others, and has a high cost/benefit ratio.
Ideally an author of such a Mini-HOWTO avoids the common mistakes, which 
  potentially lead to confusion:
- don't use 'now', 'current version', use explicite dates like '15th Jun
   2005', and full version numbers like 'kernel-source-2.6.8-15 from
   Debian Sarge'
- try to list all preconditions, which are different from a plain
   default installation
- the history listing of the console commands should be complete,
   i.e. contain even such unimportant things like 'cd ..'. Sometimes it
   is better to write 'compile the kernel with patches and install it',
   than a list of an _incomplete_ history.
- use full paths of files and directories
- use copies of the command line, where anybody can see the current
   host, current user, current directory, e.g.
   'helmut@node1:~$ cat /proc/drdb'
   Especially on clusters the node/host is important.
- describe diagnostics like you did with e.g. 'cat /proc/drbd'

BTW: As I understand, you mount a DRBD-device for the whole '/' of the 
guest. I will try the similar idea with www.linux-vserver.org instead of 
XEN.

Helmut Wollmersdorfer