Re: Has anyone compared SWRAID for (JBOD@HW-RAID) vs. (Regular Sata PCI-e cards)?

["Keld Jørn Simonsen" <keld@dkuug.dk>]

On Sun, May 11, 2008 at 12:28:17AM +0200, Keld Jørn Simonsen wrote:
> On Sat, May 10, 2008 at 01:14:02PM -0400, Jeff Garzik wrote:
> > 
> > And of course, there are plenty of other factors to consider.  I wrote a 
> > bit on this topic at http://linux.yyz.us/why-software-raid.html
> 
> So that is you writing this page! I think it is one of the more useful
> pages on raid (many others are quite outdated). 
> 
> I have a suggestion for an advantage for SW raid, that you could
> consider for your page:
> 
> - potential for increased performance, due to more intelligent layouts,
>   for example the linux raid10,f2 has more than double the performance
>   for both sequential reads and random reads compared to most hardware
>   RAID1, and Linux SW RAID1.
> 
> - potential for better error handling, due to more intelligent drivers.
>   Linux raid10 has better error handling than linux RAID1 and possibly
>   also HW RAID1.
> 
> And then, if you could link to our HOWTO pages at
> http://linux-raid.osdl.org/ that would improve the visibility for our
> pages. It seems like not many are referencing our pages, so if people on
> this list would make a link to http://linux-raid.osdl.org/ that would
> increase the chance of our information to be seen.
> 
> Best regards
> keld

Another advantage of SW raid:

- SW RAID is more flexible. On a set of drives you can with SW RAID mix
  different types of raid, for example the /boot partition could be
  RAID1 so that it can be booted by grub/lilo, the / partition could be 
  raid10,f2 for greater read performance, and the data partition could be 
  raid5 to get more effective space out of your drives. In HW RAID you can
  only allocate whole disks to one RAID type.

best regards
Keld
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html