At 2:27 AM -0500 1/16/05, Don wrote:
I didn't use the term... but was referring to formatting the drive into partitions so that each one would be inside the size limits.
I am thinking that a 10 gig drive might be divided (for example) into five 2 gig partitions so that all could be used. At one point some machines had a 2 gig size limit back there and I still seem to have a suspicion that it was done that way to let the larger drive be used.
If I'm remembering right, that drive would need to be formatted on a machine that COULD see everything correctly...and then moved over to its 'home' machine.
The 2Gb limit was due to the maximum possible volume size in the Mac OS. the 137 Gb limit is due to the maximum disk size in the drive controller. In the first case you could simply partition a drive so that each partition and hence each volume was 2Gb max. In the latter case the controller will not see any part of the drive past 137Gb so you can create a 137 Gb partition on say a 160Gb drive but the controller isn't going to see any more of the harddisk so the the remaining 23Gb is inaccessible.
The block size issue previously mentioned affects disk usage efficiency but didn't restrict volume size
In a simple system you have a disk which inside it has several partitions, at least one of which is a volume. There are always a few tiny partitions on a disk that contain disk management information such as disk driver and partition table. The rest are usually volumes. In a simple system the larger disk partitions are each a volume. In a RAID system the correlation between partition and volume becomes more complex. Disks and partitions are normally handled by the guts of an operating system and it is the volume that is presented to applications such as Finder and others. Things like RAM disks, disk images and network "drives" are volumes but not partitions or disks (at least on the local computer. Each of these logical units (drive, partition, volume) has certain numeric values associated with it and there for limits on size. Some are limited by software (the OS) and some are limited by hardware (the interface specification or controller).
The computer industry has a long history of defining standards for disk storage that at,the time, it is said that no one would ever need more. But, surprise, they just keep getting bigger. It's just amazing that these limitations don't get fixed long before they become a problem, given the history. But then again people knew that Y2 was going to be an issue 10-20 years before the end of the century but they just waited.
--
--
Clark Martin
Redwood City, CA, USA
Macintosh / Internet Consulting
"I'm a designated driver on the Information Super Highway"
-- The iMac List is sponsored by <http://lowendmac.com/> and...
Small Dog Electronics http://www.smalldog.com | Refurbished Drives | - Epson Stylus Color 580 Printers - new at $69 | & CDRWs on Sale! |
Support Low End Mac <http://lowendmac.com/lists/support.html>
iMac List info: <http://lowendmac.com/imac/list.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[email protected]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/imac-list%40mail.maclaunch.com/>
--------------------------------------------------------------- iPod Accessories for Less at 1-800-iPOD.COM Fast Delivery, Low Price, Good Deal www.1800ipod.com ---------------------------------------------------------------
