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Re: HDD partition suggestion -- raiding...



hi ya

if you have 4 18Gb drives...

why not use 3 drives as stripped disks...

and compress backups of those 3 drives to the 4th disk...

use the entire 120Gb of disk space...

if you have 40 users doing cvs...
	- you should stripe your data drives...
	- disks should be on different cables for striping...
		hda + hdd
		hdb + hdc

problem with ide disks...
	- if you are reading from hda.... you cannot read from hdb
	at the same time...unlike scsi disks...

	- but unlike scsi.... ( one cable )
	- you have 2 ide cables so you can read off 2 disks at the
	same time

to me... it doesn't make sens to use 3 drives in raid5...
	- 2 drive = data.... 1 drive is the parity...
		( 66% of disk utilization
		- and one of the 3 disks will always be slow

	with 5 disks raid5...
	- 4 drives = data ,... 1 drive is the parity
		- 80% disk utilization

-- if you use Mirror or stripping
	- you can squeeze more data onto t...

	hda = system

	hdb+hdc  == raid0 stripping

	hdd for backups...

	-- no wasted disk space


-- better still...
	- use raid10 w/ root-raid disks
	(if you wanna protect your system disk too )

	hda+hdd == md0
	hdb+hdc == md1  == mirror or md0

-- lots of fun....lots of options

-
- picture of raid differences
-
http://www.linux-consulting.com/Raid/Differences.gif/


have fun raiding...
alvin
http://www.Linux-1U.net ... 500Gb 1U Rad5 ...


On Wed, 18 Apr 2001, Karsten M. Self wrote:

> on Wed, Apr 18, 2001 at 03:15:42PM +0200, Daniel de los Reyes (dadecal@s2-selling.com) wrote:
> > I have a new server with 4 18 Gb drives. 3 of them will be on an array
> > in a RAID 5.
> > 
> > That would give me :
> > 
> > Drive 1 : 18 Gb
> > Raid 5 : about 36 Gb
> > 
> > Drive 1 is supposed to hold system and the raid array to hold data.
> > 
> > The server will have about 40 users with a disk cuota of 100-150 mb
> > Ftpserver that may grow considerably.
> > A couple of CVS repositories (in /var/ )
> > Mail for users
> > Oracle, a Lotus Domino server and a Java Development Kit are a few big things I can think of now...
> > 
> > Can you suggest me how to partition the drives?
> 
> My standard recommendations are at 
> 
>   http://kmself.home.netcom.com/Linux/FAQs/partition.html
> 
> In your case, you may want to look at deviating from the standard
> configs shown with an expanded /var, or at reparenting your webserver,
> database, and CVS repositories under /home.  I'd assume all of the RAID
> partition is presented as /home.  You could probably run with a greatly
> expanded /var to fill drive 1 as well.  Even going generous with /usr
> and /usr/local (say 3-4 GB each), you're going to have something like 
> 10-12 GB to play with on your drive 1.
> 
> Cheers.
> 
> -- 
> Karsten M. Self <kmself@ix.netcom.com>    http://kmself.home.netcom.com/
>  What part of "Gestalt" don't you understand?       There is no K5 cabal
>   http://gestalt-system.sourceforge.net/         http://www.kuro5hin.org
> 



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