The harse ain dead yet.

Well, first thing is all RAID levels create one single volume that
combines the total available drive space.  No matter what RAID level you
use, all 10 drives become one big volume, just like the 24-drive RAID 10
that I've got here.  You can partition it through Windows only if you
want to have more than one volume.

Raid 10 will always be the fastest redundant RAID.  Again, let's examine
the process for a 4-disk system:

WRITE RAID 10:
  Write to primary stripe (half of the drives, high-priority CPU cycles)
  Copy to backup stripe (half of the drives, delayed, idle-time CPU
cycles)    

WRITE RAID 5:
  Write to primary stripe (high-priority CPU cycles to all drives)
 
READ RAID 10:
  Read from primary stripe (half the drives)

READ RAID 5:
  Read from the whole stripe (all of the drives)

There's also a calculative processor delay in RAID5 that RAID 10 doesn't
have to worry about.  RAID 10 always knows where the data needs to go,
RAID 5 has to figure it out, then create a parity block for every
stripe.

You need to examine why you are asking this question-- what is your real
storage need, performance vs. volume size vs. security?  Do you need the
extra usable space with RAID 5 more than you need the 30-40% boost in
performance that you get with RAID 10?  Do you need RAID 10's extra
security of surviving a double-drive failure?

Keith


> -----Original Message-----
> From: [EMAIL PROTECTED] 
> [mailto:[EMAIL PROTECTED] On Behalf Of Matt
> Sent: Thursday, March 25, 2004 3:06 PM
> To: [EMAIL PROTECTED]
> Subject: Re: [Declude.JunkMail] Raid Controller
> 
> Not to beat a dead horse, but...
> 
> Am I mistaken about on RAID 5 array with 4 disks out 
> performing one RAID 10 array with 4 disks?  RAID 10 will do 
> double RAID 0 plus a slight hit for mirroring.  I though RAID 
> 5 with 4 disks would out perform two striped drives despite 
> the overhead.
> 
> There is another issue though.  I can only get 10 drive in a 
> packed 3U chassis, so I could only do two RAID 10 arrays, but 
> with RAID 50, drive partitions wouldn't matter if I'm not 
> mistaken, 1 would be the same as 5 partitions, or close 
> enough at least.  With 8 disks in RAID 10, I could only 
> separate the disk I/O for two logical drives.
> 
> Matt
[AUTOMATED NOTE: Your mail server [63.147.33.8] is missing a reverse DNS entry. All 
Internet hosts are required to have a reverse DNS entry. The missing reverse DNS entry 
will cause your mail to be treated as spam on some servers, such as AOL.]

---
[This E-mail was scanned for viruses by Declude Virus (http://www.declude.com)]

---
This E-mail came from the Declude.JunkMail mailing list.  To
unsubscribe, just send an E-mail to [EMAIL PROTECTED], and
type "unsubscribe Declude.JunkMail".  The archives can be found
at http://www.mail-archive.com.

Reply via email to