topic Re: RAID 53 versus 3 in Disk Enclosures

RAID 53 versus 3

Mike Fisher_5 — Wed, 27 Aug 2003 10:50:30 GMT

Hi Forummers

I'm looking at what's termed RAID 53 as an alternative to RAID 3
[Though I'm told that "RAID 03" would have been a better name for RAID 53,
because it's implemented as a striped array whose segments are RAID 3 arrays]

QUESTION 1]
All disc spindles have to be synchronised - right?

QUESTION 2]
Can someone put this info into English for me?
"Byte striping results in poor utilization of formatted capacity"
What?
I think it means that stripes are a fixed size so you can't always fill a stripe,
but that sounds too simple

Enlighten me !!

Mike
Don't get mad - get naked

BTW: If you owe Randall any points get 'em assigned now
He's only a midges d*ck away from Olympus

Re: RAID 53 versus 3

Pete Randall — Wed, 27 Aug 2003 16:21:07 GMT

Mike,

OK, I'll take pity on you since nobody seems to want to talk to you (what did you do to offend everyone, anyway?).

Here's a pretty good breakdown on RAID 53:

http://www.acnc.com/04_01_53.html

Also check the same site's description of RAID 3:

http://www.acnc.com/04_01_03.html

As to your specific questions,

1] right

2] I've found no definitive answer so I'll go with your theory (at least for the moment).

Hope this helps some,

Pete

Re: RAID 53 versus 3

Pete Randall — Wed, 27 Aug 2003 16:41:01 GMT

This touches on your 2d question (see the Storage Efficiency section):

http://www.pcguide.com/ref/hdd/perf/raid/levels/multLevel03-c.html

Here's a quote from the previously mentioned reference to RAID 3:

"Due to the restriction of having to write to all disks, the amount of actual disk space consumed is always a multiple of the disks' block size times the number of disks in the array. This can lead to wastage of space."

That's almost like English!

Pete

Re: RAID 53 versus 3

Mike Fisher_5 — Thu, 28 Aug 2003 07:06:36 GMT

Pete:
Works for me [Bill Mac (TM)]
Me & the client have decided that RAID 3 is the way to go because there isn't enough 'performance boost' on 53 to justify the increase in cost

All:
Hmmm...

I'm just considering how many points to award to that Randall character...
http://forums.itrc.hp.com/cm/UserProfile/1,,CA13182!1,00.html
He's on 19,991
He needs 9 points
He's answered my question
But on the other hand 28 of his points are for Micro$lop

What the heck
Congrats Pete...
I'm proud to announce that you're moving North across the Med & setting up your own kebab shop

I'll let someone else start the thread

Mike
Don't get mad - get naked
[Well they did in the original Olympics - but no female contestants unfortunately]