ICH7R strip size

[Jeff Woods]

Howdy.

I realize this list is more focused on Linux software RAID than 
proprietary RAID controllers, but I've been Googling and can't find 
an answer that I suspect someone on this list probably knows. If 
anyone can suggest a better forum for this question or someplace 
where the answer is documented, that would be great.


Intel's ICH7R firmware allows creating volumes in various RAID modes 
where the strip size (which I believe to be a misspelling of 
stripe size) can be certain multiples of 16KB.


IIUC, a RAID stripe is composed of chunks spanning two or more 
drives. For example, a four disc RAID-5 array with 64KB chunks would 
yield a 256KB stripe with 192KB of usable storage per stripe.


I'm trying to optimize I/O performance for a database with 64KB 
blocks. I understand that RAID-0 multiplies the likelihood of a 
failure but that's only a nuisance and not a problem in my situation.


My question: What are the chunk and usable storage sizes per stripe 
for four discs in RAID-0 on an ICH7R configured for a 128KB strip?


Thank you very much.

--
Jeff Woods [EMAIL PROTECTED] 


-
To unsubscribe from this list: send the line unsubscribe linux-raid in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: ATA cables and drives

[Jeff Woods]

At 15:16 +0200 9/16/2006, Molle Bestefich wrote:
A.) Does anyone have experience with returning Hitachi, Seagate or 
WD drives to the manufacturer? Do they have manufacturer warranty at 
all? How much/little trouble did you have with Hitachi, Seagate or WD?


A few years ago (but after IBM sold their HDD business to Hitachi) I 
had a laptop drive (48GB 2.5) die before the three year warranty 
ended. I did the diagnostic code, RMA thing and got a refurbished 
replacement which also died within a year. Repeated diagnostic and 
RMA which got me another drive which still works fine. I think the 
original two drives died because I was running the laptop they were 
in 24x7; most laptop drives are not designed for that duty cycle. The 
new drive has been great in an external USB+Firewire enclosure as a 
48GB sneakernet drive.


I've never had reason to return a Seagate or WD drive. It's been a 
few years since I used a Seagate personally. I have a 4-way RAID-0 of 
WD 74GB 10K-RPM Raptors (five year warranty) which work great. I also 
have two WD 400GB RE2 drives (also five year warranty) in RAID-0 that 
also seem great.


B.) Can anyone *prove* (to a reasonable degree) that drives from 
manufacturer H, M, S or WD is of better quality? Has anyone seen a 
review that heat/shock/stress test drives?


I can't even prove that *I* exist. ;)

C.) Does good SATA cables exist? Eg. cables that lock on to the 
drives, or backplanes which lock the entire disk in place?


WD has SecureConnect which is a SATA connecter their drives 
support. I use it and like it on all my WD SATA drives.

http://www.wdc.com/en/products/accessories.asp?ProdID=74

--
Jeff Woods [EMAIL PROTECTED]  


-
To unsubscribe from this list: send the line unsubscribe linux-raid in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html