GEOM, Vinum difference

[Rakhesh Sasidharan]

Michel Talon wrote:

> Rakhesh Sasidharan wrote:
>
>> Another (related) question: both gvinum and the geom utilities like
>> gmirror and gstripe etc provide for RAID0, RAID1, and RAID3. Any
>> advantages/ disadvantages of using one instead of the other?
>
> There has been a polemic between Greg Lehey and PJ Dawidek about the
> comparative advantages of raid3 and raid5. You can find the exchanges on
> Google. One example being:
> http://arkiv.freebsd.se/?ml=freebsd-performance&a=2004-08&t=227183
> As far as i remember there are arguments showing that raid3 is better
> than raid5 both in terms of speed and of data security. It seems that
> raid5 has mostly a hype factor for him, but i may err. Anyways it is for
> such reasons that in the modern geom system, raid3 has been implemented
> and not raid5. But vinum has been ported to the geom framework for the
> benefit of old users, or of people who like it. For example if you are
> using FreeBSD-4 or DragonFlyBSD, vinum is the standard tool, and you
> may prefer getting expertise in just one tool.
>
> Finally none of these raid systems is really good, both for performance
> and security. If you are concerned with your data and want good write
> speed, you must buy enough disks and use raid 10. Another important
> factor is ease of use.  The geom tools, gmirror, gstripe, graid3, etc.
> are *very* easy to use.  The documentation in the man pages is clear,
> sufficient for doing work, and not too long. On the contrary, vinum was
> traditionaly documented in a very hermetic way. But more recently, Greg
> Lehey has provided a very clear chapter of his book on his web site
> which can be recommanded, but is not short. Note the documentation is a
> critical aspect of such systems because its lack may bite you in case a
> disk crashes and you need to adopt correct procedures under stress.
> Also for some time the gvinum stuff was extremely buggy, and was
> completely non functional when i tried it. I hope it is fixed now.

Great, thanks Michael! :) That's just the sort of info I was looking for 
...

Regards,

 				- Rakhesh
                                 http://rakhesh.com/