Re: Hardware RAID vs. Software RAID

Hi!

The difference is on which level the multiplexing is done, if on hardware array level you have lot less IO channel usage than, software "raided" environment.

Tanel.

"Brian Peasland" <dba_at_remove_spam.peasland.com> wrote in message news:3F95AF51.C5003B6C_at_remove_spam.peasland.com...
> Not to me it doesn't. Two writes is still two writes. Does it make a
> difference whether software or hardware initiated it?
>
> Brian
>
> Chuck Lucas wrote:
> >
> > "Anna C. Dent" <anacdent_at_hotmail.com> wrote in message
> > news:Ye%kb.79328$Ms2.67542_at_fed1read03...
> > > Chuck Lucas wrote:
> > > > "Daniel Morgan" <damorgan_at_x.washington.edu> wrote in message
> > > > news:1066587431.204277_at_yasure...
> > > >
> > > >>You are correct on all points.
> > > >>
> > > >>But what version you implement can make a big difference. I'd stay
away
> > > >>from RAID 5 and vendor RAID
> > > >>implementations with numbers like 2 and 4.
> > > >
> > > >
> > > > What's wrong with RAID 5?
> > > With Raid-5 the redundancy information is stripped across all disks.
> > > For EVERY data block which is written to a RAID-5 volume the parity
> > > block must be recalcuated and also written to disk. For all intents
> > > and purposes RAID-5 doubles the number of write operations to disk.
> > > As the percentage of WRITE to READ operations increases available
> > > useful/application disk throughput decreases.
> > >
> > Wow! I didn't expect this much of a response. Thanx, folks, for the
input.
> > I, OBVIOUSLY, have some more research to do, huh?
> >
> > But I did notice throughout this that it seemed as though you guys were
> > talking about software RAID5. I'm using hardware RAID5...does that make
any
> > difference in your opinions?
> >
> > Off to my research, now. Again, thanx!
> >
> > Chuck
>
> --
> ===================================================================
>
> Brian Peasland
> dba_at_remove_spam.peasland.com
>
> Remove the "remove_spam." from the email address to email me.
>
>
> "I can give it to you cheap, quick, and good. Now pick two out of
> the three"
Received on Sat Oct 25 2003 - 07:32:51 CDT