kimac: iMac CRT - Files have incorrect sizes, too big
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This generally happens when a hard disk has been formatted using Mac OS Standard format (HFS) instead of Mac OS Extended format (HFS Plus). HFS has a limit of 65,536 allocation blocks which means that large hard disks end up with large allocation blocks. HFS is inefficient for large drives (greater than 256 MB). See Knowledge base article #8647, Macintosh: File System Specifications and Terms and Knowledge base article #30344 for more information.
An interesting quote from article #30344 is " As an example, on a 4 GB hard drive a file containing only 4K of information requires 64K of space in Mac OS Standard format, whereas with the Mac OS Extended format, it will require the actual 4K on the 4 GB hard disk." This means that HFS wastes 60K of disk space for that one file.
There are 2 ways to remedy this situation:
- Reformat the drive in HFS Plus, remember to back up important data and applications before doing this.
- Use Alsoft's PlusMaker to convert the disk to HFS Plus. It is still recommended to back up all important data and applications before doing this.
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