question on vinum

[Mikhail P.]

On Wednesday 27 October 2004 05:33, secmgr wrote:
> > I have read the handbook articles, and I got general understanding of
> > Vinum. I'm particularly interested to know if I will still be able to use
> > volume in case of failed drive.
>
> If you want to do that, then you want raid5.  If either a concat or
> stripe set looses a drive, the data will need to be restored.

Are there known methods/techniques to restore data from failed concat or 
stripe volumes?

>
> > Some minimal configuration examples would be greatly appreciated!
>
> Read the following.  Really!
> http://www.vinumvm.org/vinum/vinum.ps
> http://www.vinumvm.org/cfbsd/vinum.txt
> Both of these have examples and will clear up your confusion about
> concat vs stripe vs raid5.
>
> concat is the easiest to add to, stripe has the best performance, raid5
> trades write speed and n+1 drives for resilience.  raid10 gets back the
> performance at the cost of 2*n drives

Thanks. Your explanation really helped me a lot.
Does striping require an additional drive too? Or it is very similar to 
concat, except for it stores data across all the spindles? Does it also mean 
that it is harder to recover stripped volume?

As for raid5 - it requires an additional drive. Are there any requirements for 
the drive? E.g. would it work as having 3 x 200GB for stripe + additional 
20GB drive that will be used for control blocks? And what happens here if 
20GB drive fails - will I be able to rebuild it and continue using raid?

> hopefully I haven't made you're understanding worse

Thanks, it made my understanding better for sure.

regards,
M.