[BlueOnyx:00962] Re: What to store on a separate disk

[Michael Stauber]

Hi Julien,

> as I'm running BX on Amazon Cloud (where persistence of data is
> guaranteed only if using external volumes/partitions), I have already
> set my virtual machine to attach and mount a partition /home
> externally so that, in case the virtual machine gets broken, I don't
> loose all sites/mails and so on.
>
> What I was wondering is:
> - What other directory are important ?
>
> As when you shutdown (terminate) a virtual machine in Amazon Cloud all
> data stored in the virtual machine after that it has been created gets
> lost, I was wondering what other dirs/folders are importart to be
> saved.

I'd say this pretty much eliminates BlueOnyx from being used on an Amazon 
Cloud and would generally advise against using it there.

There is quite a bit of data outside the /home partition that is important - 
and not just MySQL.

>From /etc/ alone you need a ton of stuff, including /etc/mail/, sendmail.cf, 
sendmail.mc, proftpd.conf, webalizer.conf, named.conf, the /etc/named/ 
symlink, some stuff from /etc/sysconfig/ and what not. If you run any accounts 
other than admin and/or run sites with or without users, then include 
/etc/passwd, /etc/shadow, /etc/group, /etc/hosts

Ah bloody hell. You almost need half of /etc/ when I think about it.

Then you need /usr/sausalito/codb/ or your BlueOnyx GUI will loose it's brain. 
Assuming you install third party software that brings extra GUI pages aboard 
you will even need more than just /usr/sausalito/codb/ 

You'll also need /var/lib/mysql/ and if you're running DNS you need the zone 
files from /var/named/chroot/var/named and assuming you run a mailserver you 
also need /var/spool 

But this all brings us to the next point: If the OS or the data in the cloud 
is not persistent over reboots: What about YUM updates? If you run a YUM 
update and whatever that brings aboard is not persistant, then what's the 
point in using a cloud? 

Even saving the data on a remote volume will you not let get past the obstacle 
that OS updates or patches will sooner or later cause inconsistencies there.

I think you may be better off if you use another approach: Install something 
in the cloud that allows you to virtualize BlueOnyx (VMware, VirtualBox, Xen 
... whatever!) and store the virtualized BlueOnyx on the remotely mounted 
disk. Voila! Problem solved. Because then your BlueOnyx is "stock" again, 
persistance is ensured and it's even "portable" as you wouldn't really depend 
on being stuck with Amazon's cloud. Because if that (for whatever reason) is 
no longer an option, you could simply install your virtualization stuff 
somewhere else and again mount the drive where the virtual server is stored.

-- 
With best regards

Michael Stauber