Could anyone explain the difference and the purpose of "Sparse" and "Sparse bundle" disk images types? I've googled 'em up, but found nothing meaningful 😟
Thanks in advance! 🙂
MBP 3.1 15",
Mac OS X (10.5.6),
Intel C2D 2.2 GHz, 4 Gb RAM & etc.
A sparse disk image is an automatically expanding disk image. In other words, you can create a 50 gigabyte sparse disk image, yet only put 5 megs inside it. The disk image will only take up five megs of space on your harddisk, but will be capable of storing up to 50 gigs of data should you choose to add it. Note that it auto-expands but does not auto-contract. In other words, if you delete files from the image, you will not regain any free space on your harddisk (although you will on the image). Disk Utility can be used to "shrink" a sparse image, reclaiming any unused space on the image.
A sparse bundle is essentially the same thing, the only difference is that while a sparse image is one giant file on your disk, a sparse bundle is actually lots of small files (8 megabytes each). They work and look the same way, but you can right-click on a sparse bundle, select "show package contents" and see the individual 8 meg "bands".
The sparse bundle was introduced with OS 10.5 in order better support Time Machine (Especially with FileVault, where the entire home directory is a sparse bundle). Previously, a backup programme would see the image as one file, and if any changes had to been made to it, it would have to recopy the entire image. With sparse bundle, it can only copy the bands that have been changed since the last backup, so the backups are much quicker. It also is likely to decrease the chance of data loss, as you could conceivably restore parts of a damaged image.
Basically, if you want a sparse image, use the sparse bundle under 10.5. Only use the sparse image if you need backwards-compatibility with earlier versions of the Mac OS.
A sparse disk image is an automatically expanding disk image. In other words, you can create a 50 gigabyte sparse disk image, yet only put 5 megs inside it. The disk image will only take up five megs of space on your harddisk, but will be capable of storing up to 50 gigs of data should you choose to add it. Note that it auto-expands but does not auto-contract. In other words, if you delete files from the image, you will not regain any free space on your harddisk (although you will on the image). Disk Utility can be used to "shrink" a sparse image, reclaiming any unused space on the image.
A sparse bundle is essentially the same thing, the only difference is that while a sparse image is one giant file on your disk, a sparse bundle is actually lots of small files (8 megabytes each). They work and look the same way, but you can right-click on a sparse bundle, select "show package contents" and see the individual 8 meg "bands".
The sparse bundle was introduced with OS 10.5 in order better support Time Machine (Especially with FileVault, where the entire home directory is a sparse bundle). Previously, a backup programme would see the image as one file, and if any changes had to been made to it, it would have to recopy the entire image. With sparse bundle, it can only copy the bands that have been changed since the last backup, so the backups are much quicker. It also is likely to decrease the chance of data loss, as you could conceivably restore parts of a damaged image.
Basically, if you want a sparse image, use the sparse bundle under 10.5. Only use the sparse image if you need backwards-compatibility with earlier versions of the Mac OS.
