I just finished a project to partition my hard drives for an increase in available space. Actually, I got the idea from the APS drive folks, who offered a writeup on the APS Toshiba 520M Hard Drive by house guru Steven Bobker. Bobker writes,

"This drive is too big for most users to leave as one volume. If you do, the minimum file size will be 8K. That means that aliases which typically use between 512 and 2000 bytes will occupy 8192 bytes each if you leave this drive partitioned as a single volume. I've split mine into 5 volumes [4 of 95M (1.5K minimum file size) and 1 of 120M (2K minimum file)]."

I'm running three drives in the 240M range - one internal, two external. When I started seeing 5K aliases on the 270M Maxtor, I knew I was throwing away space. Block size on that drive was 5K, so the 1K alias was wasting 4K and nothing else would ever be written to that block. Similarly, the 6-9K text or code file (of which I have thousands) will fill up the first 5K block and write only 1K to the next 5K block.

To keep the playing field level (and make room for the partitions), I first de-fragmented all the drives with Norton Speed Disk 3.1. Many of these files are compressed by AudoDoubler/Disk Doubler, and these utilities display uncompressed finder sizes. To keep everything apples to apples, all Finder size measurements were made with extensions turned off, to show current physical file sizes before and after file moves to the new partitions.

How much space did I save in actual practice?

Here are my results, with before-and-after Finder file sizes (actual physical file sizes):

Created FROM:  240MB HD partition
PARTITION:  'FILES'
25MB		OLD		NEW		pct		#items
E-Mail Center	9.2M		6.1M		34%		1,435
GIA folder	6.2		5.9		%		254

Created FROM: 270MB HD Partition
PARTITION:  'DEVELOPMENT' 80MB
FSI.DTS 	1.6		1.5		7%		62
THINK C		18.5		15.4		17%		1,765
THINK Ref.	7.5		7.5		0%		11

AVERAGES:	43MB		36.4MB		15%		--

Conclusions: Volumes and folders containing a great many files benefit the most from smaller block sizes. Volumes and folders with few files, and hefty files and applications, benefit the least, or not at all. The greatest savings resulted in a move of many small files in 'E-mail Center' from a large unpartitioned hard drive to the small 25MB partition.

Other observations: I can see two reasons why the THINK C folder didn't realize the same savings as the eMail folder: The Development partition is larger (alias size 2-3K), and C contains several very large files, including the application itself.

I'm impressed. MacWorld Labs could have done a more scientific study than this one, but the results show me that I can justify turning off the elaborate AudoDoubler/Disk Doubler file compression scheme entirely if I want. (My most active files and applications are already set to "don't compress", so I don't save as much space).

All formatting and partitioning was done with FWB Hard Disk Toolkit 1.6, and all partitions were made "expandable" to provide room to grow. Other reputable brands should do an equally fine job for everything. I no longer use Apple's "Disk Tools" for anything but its convenient minimum System, by the way.

I have these partitions set for "automount", so they're there on the desktop all the time. This can be turned off so you can mount, say, Development, only when you need it.

I also use a small unmounted password-protected partition for personal stuff: journals, personal archives, and the like. Not that there's any real scorchers, or anything worth stealing. I would still feel awful if the drive were stolen, and strangers started phoning my love letters back to me, or Doubleday came out with a new best-seller with my thoughts and somebody else's name on it. One can encrypt such stuff with FWB and most top-of-the-line drive utilities, or with shareware DES encryption schemes even the CIA couldn't crack. I don't bother. You have to draw the line somewhere.

Norton no longer supports either Norton Partition or Norton Encrypt, so it's nice to know there are state-of-the-art ways of accomplishing these tasks.

File this away in case you're running drives over about 160MB, or you are ever bothered by long finder waits and file searches, or would just like to save some room and use your existing drives more efficiently.

Alex Forbes 11-22-1994

eWorld: Phaedrus47

POSTSCRIPT, 10/30/95: I recently had to reformat a powerbook drive with four partitions. I backed them up to an unpartitioned 500MB drive. The smallest volume (my private "cache") occupied 9.9MB on the backup. I created a new 12MB secret partition for the restore. The restored secret partition contained 5.7MB, better than a 40% reduction in storage from the large unpartitioned volume.

There really is something to this stuff. If you ever wondered, "Now, how in heck am I going to get all this stuff back on that volume?", there's your answer. To estimate what your space used/needed is going to be in volume transfers, calculate a proportion based on alias sizes. And, do this first, before you establish the sizes of new partitions.

No wonder, that many people just dump stuff onto 1 and 2GB volumes until full? Well, it never makes any difference how much space a file consumes on a volume, until we need more than is available. The one and two gig owners who don't partition are really running much smaller drives than they paid for, unless all their files are 50-100MB Photoshop JPEGS.

For most of us, published drive capacity is only a relative storage indicator: an absolute number of bytes, plus whatever allocated disk space is needed to completely fill up the last block. For those "most of us" whose files are numerous and small, mostly in the 1K-20K range, block size (the size of an alias) has become the dominant storage factor.