Strange backup sizes in Time Machine

[cooky560 Veteran]

Basically I decided to try using time machine on a new USB drive, since my old one went kaput and is now in the trash.

And I noticed an odd discrepancy:

Computer:

Disk Usage on Volume HDD 101.52GB

FS: HFS+ (Journaled)

Time Machine Backup:

Backup size 126.4GB

FS: HFS+ (Journaled, Encrypted)

OSX 10.8.2

Now since Time Machine doesn't backup caches, and various other things, surely the Time Machine Backup should be SMALLER not ~20gb larger?

[cooky560 Veteran]

Bump, anyone?

[.Neo]

Time Machine stores and keeps snapshots of your files each 24 hours. Obviously your backup size will start exceeding the used space on your Macintosh HD at some point. It all depends on how frequently you modify and add files.

[cooky560 Veteran]

That's a nice theory Neo, apart from it's the first backup I've made on this disk.

[.Neo]

Time Machine also makes hourly backups that are deleted after 24 hours. Other than that it could be the encrypted file system, but that's just pure speculation on my part.

[cooky560 Veteran]

If time machine takes longer than hour to complete the first backup, will it start a second backup (since you said they are hourly)?

[Matthew S.]

It also makes a bootable recovery (if it's the first time backing up) ...