RE: Back to the RAID question

My biggest concern is that this drive will PRIMARILY be binaries:
programs, Java code, and so on.  Or at least that's what I'm most
worried about for performance.  WDSC, web application serving, that sort
of thing.  And all anecdotal evidence points to RAID 1 as the best way
to go for this.

But the more I read, the more points towards RAID 5.  At that point I as
pretty comfortable with RAID 5.  But the increased performance of RAID
5EE got me thinking I should go there, at which point added cost and
longer rebuild time made me rethink the RAID 1 concept, and especially
the RAID 10.

So, yeah, I'm in the midst of analysis paralysis and I really need to
just pick something, but boy it's been an interesting ride and I now
know more about RAID than I ever wanted to <grin>.

Joe

P.S. Even though I'll also run SQL Server on this machine, it should
only be for small databases.  Any large databases will probably be
located on either the iSeries or on a separate network drive.  Can SQL
Server serve data from a network drive?


> From: Walden H. Leverich
> 
> >Kill me now.
> 
> Hmmmmmm.....  :)
> 
> Joe, you're asking performance questions, and you know the answer to
all
> performance questions is "it depends." Seriously, what's better for a
> server is not necessarily what's better for a single user, and beyond
> that, what's better for sequential IO (like a log file) is not
> necessarily what's better for random IO. And what's better for read is
> not necessarily better for write. And what's better for large-block IO
> is not necessarily what's better for small block IO, so in short, it
> depends.
> 
> If I understand all the proposals you've posted you're looking at a
> single logical drive (C:). From a performance point of view you should
> also consider separating your machine into two, or ideally three, sets
> of spindles, one for system & program, one for swap and one for data.
> Obviously these spindles could be a combination of RAID 0, 1 and 5.
> 
> FWIW, my machine at home is a 10K SATA drive for system & Program (no
> raid, if I loose it I reinstall), two RAID 0 drives for SWAP/TEMP
> (again, if I loose a drive I'm toast) but I gain the speed from RAID 0
> and data resides on a mirrored pair of drives.
> 
> Stop asking "it depends" questions, and buy the darn machine. Unless
you
> run it side-by-side with one of configured another way you'll never
know
> if you have the best, worse, or just an average configuration anyway,
so
> just tell yourself that the one you pick is the fastest and move on.
> 
> -Walden
> 
> 
> ------------
> Walden H Leverich III
> Tech Software
> (516) 627-3800 x11
> WaldenL@xxxxxxxxxxxxxxx
> http://www.TechSoftInc.com
> 
> Quiquid latine dictum sit altum viditur.
> (Whatever is said in Latin seems profound.)
> 
> 
> -----Original Message-----
> From: pctech-bounces@xxxxxxxxxxxx [mailto:pctech-bounces@xxxxxxxxxxxx]
> On Behalf Of Joe Pluta
> Sent: Tuesday, September 13, 2005 10:48 AM
> To: 'PC Technical Discussion for iSeries Users'
> Subject: RE: [PCTECH] Back to the RAID question
> 
> I'm still bashing my head over the RAID question, though.  RAID 5 is a
> better price/performance than RAID 1, and according to IBM, RAID 5
> actually tends to outperform RAID 1 due to number of spindles.  So,
for
> instance, where I to use five 36GB drives ($1500) to create a 146GB
RAID
> 5 array, this would theoretically outperform a two mirrored (RAID 1)
> 146GB drives ($2000).
> 
> More hitches: throw in an extra drive and you get RAID 5E (which has
> already been superseded by RAID 5EE).  Better performance, but slower
> rebuild time and you lose a drive.  So now the question is this: does
a
> five-drive RAID 5EE array (108 GB) perform better or worse than a
> six-drive RAID 10 array?
> 
> Does a four-drive RAID 5EE array outperform a four-drive RAID 10
array?
> Does a six-drive RAID 5EE array of 36GB drives ($1800) outperform a
> four-drive RAID 10 array of 73GB drives ($2000)?
> 
> Kill me now.
> 
> Joe
> 
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