Storage cluster with FreeBSD

[Norberto Meijome]

On Fri, 26 Oct 2007 13:51:36 +0200 (CEST)
Wojciech Puchar <wojtek at wojtek.tensor.gdynia.pl> wrote:

> > cool, thanks for the pointers... I had a side note to review these in conjunction with ggate.  
> So, is there any logical volume manager that works properly under 6.x or 7, ala LVM2 in Linux?
> 
> there is gvinum, but i can't say "it works right". it's quite easy to 
> crash, at least was for me.

so i've read...

> 
> but - freebsd allows 7 partitions, but partitions can be recurrent - i 
> mean you can use bsdlabel on partitions and get things like ad0aa etc.
> 
> i used this to make 30 partitions.

interesting...

> 
> so it's "manual LVM" as then you can ggate, gmirror or gconcat or gstripe 
> with that partitions.

sorry, i don't see how this recursive formatting of partitions can be used as a
'manual lvm'... see below

> 
> precise more clearly what you need. as always - simple solutions are best 
> solutions. and unix == simplicity.

indeed. Well, as I said in OP, similar to what Lustre offers. 

Let's see : what I am after is a way to hook up a few computers ( say, 6) with
a few  HD (say,  6 x 400 GB), and setup across the whole thing a RAID that
would let me :
 - keep running with no loss of data  in case of a disk or node failure (or
minimal in case of a node failure)

 - can be accessed by clients over standard network protocols (NFS, CIFS, etc)

 - the clients see volumes of x GB (maybe 1 of the total size, maybe 3 of
different sizes...doesn't matter)

All this until hear seems doable with FBSD + GEOM architecture. Now the tricky
ones :

 - scales linearly - if I add 90 storage hosts, the system doesnt get bogged
down with the management of the disks / stripe distributoin

 - I can add new hosts (from 6 to 10) and the new storage is available for the
cluster. If I had LVM, I could simply add the new disks to the physical group,
and then grow the logical volume... I don't see how 7.0's recursive
partitioning can help me here.... Can you please explain ? 

thanks!
B
_________________________
{Beto|Norberto|Numard} Meijome

"There are two kinds of stupid people. One kind says,'This is old and therefore
good'. The other kind says, 'This is new, and therefore better.'"
 John Brunner, 'The Shockwave Rider'.

I speak for myself, not my employer. Contents may be hot. Slippery when wet.
Reading disclaimers makes you go blind. Writing them is worse. You have been
Warned.