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Hard Drive partiton

S

sdhollman

macrumors regular
Original poster
Nov 16, 2005
170
0
Toronto, Ontario
What is a good amount of space to leave for your OS and such when partitioning a hard drive? I have never done this but I have heard it is better to do and will help with speed. I want to set up my Mac Pro correctly and though I should do this.

Any suggestions?
 
sdhollman said:
What is a good amount of space to leave for your OS and such when partitioning a hard drive? I have never done this but I have heard it is better to do and will help with speed. I want to set up my Mac Pro correctly and though I should do this.

Any suggestions?
Click to expand...

Partitioning 1 drive will not help at all with speed.
If you want to improve performance buy a second drive and create a raid 0 (striped) partition across them, or keep one for OS and the other for homedir and scratch space.


M.
 
MikeDTyke said:
Partitioning 1 drive will not help at all with speed.
If you want to improve performance buy a second drive and create a raid 0 (striped) partition across them, or keep one for OS and the other for homedir and scratch space.


M.
Click to expand...

Any tutorials on how to do this? Do I need a raid controller then? :confused:
 
MikeDTyke said:
No, Mac's predominantly use software raid. You use disk utility to format, partition and create raid volumes.

I'd read http://www.macprojournal.com/home.html

Plus google for "macos raid 1 partition howtos" you'll get a miriad of articles.

Regards
M.
Click to expand...

Ok cool. I will look into to this. Do I have to set up a raid when I get my computer or is this something I can do down the line?
 
MikeDTyke said:
Partitioning 1 drive will not help at all with speed.
M.
Click to expand...

I thought that it can, eg by creating a partition for the OS and swap files you can ensure that these files are near the spindle of the disk and hence quicker to access and potentially free of fragmentation. But maybe I'm wrong!

b e n
 
sdhollman said:
Ok cool. I will look into to this. Do I have to set up a raid when I get my computer or is this something I can do down the line?
Click to expand...

It's best to create raid partitions from identical disks. If you manage to find an identical drive to the one shipped in your mac, you won't be able to reformat it to create the raid.

I'd wait and when you see a good deal on drives from say Newegg or eBuyer, buy 2 then create the raid on those. I bought a pair of 250Gig Western Digitals for £43 each 6 months ago, created a 500GB stripe across them. Once raid is up and running it's a doddle to transfer all files across from original drive to new raid using something like Carbon Copy Cloner. Google it if you've not heard of it. Then i'd use the old original drive to backup files to, especially useful when Leopard comes out and you want to use the TimeMachine function.


M.
 
lazydog said:
I thought that it can, eg by creating a partition for the OS and swap files you can ensure that these files are near the spindle of the disk and hence quicker to access and potentially free of fragmentation. But maybe I'm wrong!

b e n
Click to expand...

Fragmentation isn't really the problem. One area that partitioning a single drive might help is splitting the OS away from Apps/Home and anywhere that files are created. Macos turns into a dog when the root partition (OS) gets close to full. I'm fairly anal about how my hard drives fill up, never let root get below 10GB free. But perhaps for someone who's not so fastidious, it'd might be worth doing.


M.
 
lazydog said:
I thought that it can, eg by creating a partition for the OS and swap files you can ensure that these files are near the spindle of the disk and hence quicker to access and potentially free of fragmentation. But maybe I'm wrong!

b e n
Click to expand...

-lazydog

Actually, anymore the area of fastest access is at the edge of the disk because there are more bits there.

"Woah! Ok, Patrick, what the hey are you talking about?!? I always thought that the density is more spread out at the edge, like a pie?"

Well, yes, it used to be true, but not anymore. Zoned Bit Recording, is our friend Linkypoo. Illustration

Your best solution is to really have more than one separate physical partitions - two disks. Striping works, yes, but it also doubles your odds of failure because you are doubling the mechanisms of that failure. Either drive goes, your whole striped drive goes with it. Also, you can't have a software RAID as a boot disk - bit of a chicken-and-egg problem there. Also, another though occurred: if you logical partition as you suggest, you halve your performance and impact your drive's lifetime as you will be asking twice as much from the slider.

Just get some big honkin' drives and don't worry about Fragmentation because Journaling takes care of that, and don't worry about crusty blocks as FSCK takes care of that on startup.
 
lazydog said:
I thought that it can, eg by creating a partition for the OS and swap files you can ensure that these files are near the spindle of the disk and hence quicker to access and potentially free of fragmentation. But maybe I'm wrong!

b e n
Click to expand...

Disk space close to the spindle of a disk is the worst performing, not the best. The best performance is out at the edge of the disk, since the cylinders / tracks are much bigger (think circumference). Since each track holds more data, the disk head doesn't need to move as frequently or as far.

There's nothing to be gained by partitioning a disk, other than a loss of flexibility. Think about what happens when that X GBs you set aside for the OS partition fills up 2 years down the road. Just make one partition and allow the space to be used for whatever purpose that's needed. The OS and swap are always going to be written to a fresh disk first, nice a neat.

The only real reason to partition a single drive is if you need more than one boot partition, i.e. you have multiple OS's installed on the same drive, ala Bootcamp.
 
daveL said:
Disk space close to the spindle of a disk is the worst performing, not the best. The best performance is out at the edge of the disk, since the cylinders / tracks are much bigger (think circumference). Since each track holds more data, the disk head doesn't need to move as frequently or as far.
Click to expand...

Yup, my mistake.

I'm not totally convinced though about not having a partition just for the OS and swap files. If you do this then you can be sure that if your disc does fill up these files won't suffer from fragmentation. I suppose, like you said, it's not so much of a problem if you can add another disc, but if you're on a laptop it might be a problem… but then this is a Mac Pro thread so I'll shut up!

b e n
 
sdhollman said:
Thanks Patrick. SO it is best to leave it and enable journaling? What dose journaling do exactly?
Click to expand...

-sdhollman

Journaling prevents file fragmentation by building a database that watches every single bit and keeps them connected, and contiguous with others of the same file.

Consider it live defrag.

The default behavior is that Journaling is enabled but use Disk Utility to be sure.
 
Back in the day.....disk management was an absolute necessity for performance. I get a chill thinking about all of the set-up and management chores we used to have to go through. Nowadays, it is all easy street.

Personally, I never let my boot/system drive get anywhere near to full. The only thing I keep there are my OS, System Directories, Swap, Applications, and most libraries. For my system, this chews up about 115 GB, leaving 112 GB free. That is plenty of room for adding new applications.

I also like to have one drive dedicated for working space, and another drive for archiving completed work. Finally, I have external drives for back-up. This may seem redundant, maybe even obsessive. But the last thing I want to worry about is drive space, or losing work.
 
SMM said:
I also like to have one drive dedicated for working space, and another drive for archiving completed work. Finally, I have external drives for back-up. This may seem redundant, maybe even obsessive. But the last thing I want to worry about is drive space, or losing work.
Click to expand...

-SMM

I'm in the same 'excessive' boat. Have a LaCie for Cloning.

Can't wait for Time Machine for incrementals...
 
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