How necessary is it to reserve 15% disk space? - Page 2

**mdnky** · #9 February 20th, 2005, 05:01 PM

Personally, I keep at least 25% free. The number you pick, of course, would depend on your HD/system config and the stuff/apps you run, but I'm figuring on a 40GB one with the iBook. 25% or more free, the iBook runs great. Slightly slower down to 15% or so, then anything less and it slows down noticeably.

RacerX · #10 February 20th, 2005, 09:57 PM

Quote:

Originally Posted by Viro

I've never heard of such a thing with other file systems and it instantly makes me suspicious that HFS+ would be so ... unreliable. Anyone know how reliable this information or if there are any official documents from Apple that support this claim? 15% of my hard drive is 9 GB which is a *lot* of wasted space.

That is a very real safety limit. And what is worse, I've seen (and had to repair) the damage caused by not following that limit.

It is a soft limit though. You can run at less than 15%, but I wouldn't do it for very long. And if you are running at less than 5% I would suggest making sure you have your data backed up.

The types of problems that come from this are in the HFS catalog section of the disk. They can make a disk unmountable or even strip away the hierarchal file system (basically explode all the folders so all your files are on the root level of the drive).

It is not fun to clean up, and you may need expert help in salvaging the info on the disk. At any rate, reformatting is the only real way to bring the disk back to a completely usable state.

As for how long this 15% free space limit has been around, it has been well known in the Mac service community for years (I first heard about it in 2000). My first experience with it came in 2001 with an AppleShare IP system that was running at over 97% full for a few weeks. As it had exploded tons of flight checked QuarkXPress project folders on an 80 GB drive, most of those folders were never put back together.

Randman · #11 February 21st, 2005, 04:41 AM

With the price of external HDs so low (and dropping each day), space shouldn't really ber a problem.
After ram, I'd say the second-most important aftermarket purchase should be an external for backups and saving space. (iPods are also good for this).

Viro · #12 February 21st, 2005, 04:51 AM

Great..... so the danger is real. My 60 GB drive has about 21 GB free at the moment so the danger isn't imminent. However, if I were to add more stuff to my machine, I'll need more space since in reality if we took into account the 'safety limit' I actually have about 12 GB free!

Looks like I have to look into buying one of those 100 GB laptop drives. Or move to another OS that doesn't use such a bad FS

.

Randman · #13 February 21st, 2005, 04:59 AM

Again, why not get an external?

Viro · #14 February 21st, 2005, 06:54 AM

Because that'll mean I need to lug an external drive with me. It works most of the time, but then there could be stuff on the external drive that I need but I forgot to bring along if I went to a conference or some far out place.

I've got a 60 GB external drive at the moment, and I'm only using that as a backup solution.

Randman · #15 February 21st, 2005, 07:02 AM

You have a 60GB drive and you're worried about not having enough room? What are you keeping on it? Video? Music?

powermac · #16 February 21st, 2005, 07:18 AM

I have never heard of a magic number. Certainly 5GB of space is a safe bet. I keep just what i need on my PB and everything else is on my external. An external drive, in my opinion, is necessary for a laptop owner.