Defragging Raid drives. at DVinfo.net

Go Back   DV Info Net > Windows / PC Post Production Solutions > Non-Linear Editing on the PC

Non-Linear Editing on the PC
Discussing the editing of all formats with Matrox, Pinnacle and more.


Reply
 
Thread Tools Search this Thread
Old January 17th, 2008, 05:05 PM   #1
Inner Circle
 
Join Date: Sep 2006
Location: Sydney.
Posts: 2,569
Defragging Raid drives.

When you're defragging a Raid one setup, that's twin drives with identical files on the second drive, does Win XP defrag the second drive simultaenously?
Cheers.
Allan Black is offline   Reply With Quote
Old January 17th, 2008, 05:20 PM   #2
Inner Circle
 
Join Date: Feb 2007
Location: Fairfield, Dunedin, New Zealand
Posts: 3,634
Images: 18
Hi Allan..........

Think that goes top of my "Q of the week".

Really made me think, that one.

I honestly don't know the answer, but a bit of grey cell bashing makes me surmise the negative. As the drives in a Raid config do not need to be identical in any way (and even if they were, there's no reason to believe the files would be identically placed on each drive) then I figure each drive is treated individually.

The defrag software would not be aware of the copy on the other drive nor does it need to (the Raid software is doing that) so, logic dictates the defrag will do what it usually does if fed to a string of drives - start at the top and work down. Quite how it selects which of the drives to start on first is a mystery.

Not sure if that's been any help at all.


CS
Chris Soucy is offline   Reply With Quote
Old January 17th, 2008, 05:35 PM   #3
Major Player
 
Join Date: Oct 2007
Location: Paradise, california
Posts: 353
The way I understand a raid one, windows sees them as one drive, the information is treated identically. of course, its possible my thinking is wrong...
Allen Plowman is offline   Reply With Quote
Old January 17th, 2008, 06:28 PM   #4
Trustee
 
Join Date: Jun 2005
Location: Hollywood, CA
Posts: 1,675
Images: 1
I think Chris really hit on the key point here, in that it's not Windows that determines what the second drive does, but the RAID management software. It may simply send duplicate read/write commands to the second drive no matter what it's fed.

My guess is that both drives are defragged, as the management configuration probably can't tell the difference between a defragmentation and typical read/write access.
__________________
BenWinter.com
Ben Winter is offline   Reply With Quote
Old January 18th, 2008, 04:34 PM   #5
Inner Circle
 
Join Date: Sep 2006
Location: Sydney.
Posts: 2,569
Guys, some ferreting around reveals, defragging a Raid 1 set-up does do both drives simultaneously.

But try 'error checking' ...using Win XP Pro, it took over 2 hours to error check 74 (alias 148) Gigs on a Raid 1 2TB My Book external drive.

What's it gonna be like if ever I manage to fill the thing up, like to set it off just before I go on holidays.
Allan Black is offline   Reply With Quote
Old February 8th, 2008, 11:42 AM   #6
Major Player
 
Join Date: Oct 2007
Location: Hampshire
Posts: 226
Not sure ..

Hi Chaps,

RAID0 (I use) treats two discs as one and therefore defrags as one. It would make sense to me that RAID1 was defragged disc by disc starting with the disc of your choice if doing it manually or however you have scheduled defrag to run - 1 only or 1 and others.

I would think it would be out of scope for it to be able to defrag two independent discs at the same time as there would be way too much processing to complete when trying to establish contiguous files.

Simple answer to this is try it - if it won't - it won't, there should be no harm done in any event.

Cheers
Dave
Dave Gosley is offline   Reply With Quote
Old February 8th, 2008, 05:00 PM   #7
Inner Circle
 
Join Date: Sep 2006
Location: Sydney.
Posts: 2,569
Hi Dave, the RAID1 system mirrors the data to 2 drives simultaneously; from my research so far, so does defragging a RAID1 rig.

Cheers.
Allan Black is offline   Reply With Quote
Old February 8th, 2008, 05:06 PM   #8
Major Player
 
Join Date: Oct 2007
Location: Paradise, california
Posts: 353
even common sense says each bit on each drive must be in identical places, using the same address. thats why its a "mirror". if one drive was fragmented, and the other was not, the information would have to be read at separate times for each drive, and written separately.
__________________
"What I need is an exact list of specific unknown problems we might encounter."
Allen Plowman is offline   Reply With Quote
Old February 8th, 2008, 05:18 PM   #9
Inner Circle
 
Join Date: Sep 2006
Location: Sydney.
Posts: 2,569
Exactly Allen; I've got 2 years of clips, for an aircraft restoration society on a 2TB WD My Book RAID1 rig. 280GB so far, I defrag after every session.

Backing that up is another story however.

Cheers.
Allan Black is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Windows / PC Post Production Solutions > Non-Linear Editing on the PC

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 01:57 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network