Time Machine back-ups bit per bit?

[HiFiGuy528]

In the audio world, bit per bit is important. When TM makes back-ups, are they bit per bit of the original?

 

[PrinceOfEgypt]

In the audio world, bit per bit is important. When TM makes back-ups, are they bit per bit of the original?

i might be missing something, but how else could it be? the files are copied to the backup drive.. bit per bit is the only way i know of to make a copy of a file..

 

[Amdahl]

I don't know what the opposite of bit-per-bit is, but I can tell you that Time Machine does not do incremental back per file. If you have one gigantic file, and a single bit changes in that file, Time Machine recopies the whole file. This is why Virtual Machines are often automatically excluded from Time Machine and must be backed up separately.

 

[brand]

I can tell you that Time Machine does not do incremental back per file.

Actually Time Machine does perform incremental backups on a per file basis.

 

[Amdahl]

Actually Time Machine does perform incremental backups on a per file basis.

Perhaps I have the wrong words, but what I thought I wrote is what I was thinking, and is correct. 😉

Using the definitions available at your link, I should have said 'doesn't do block-level incremental backups'.

 

[mlts22]

If you have a huge file like a VMWare virtual machine image, what helps is to put it in a sparsebundle disk image. Then when Time Machine goes to back things up, it will just need to back up the 8 MB bands that were changed rather than the complete file.

 

[Amdahl]

If you have a huge file like a VMWare virtual machine image, what helps is to put it in a sparsebundle disk image. Then when Time Machine goes to back things up, it will just need to back up the 8 MB bands that were changed rather than the complete file.

Serious? That would be great. Is there a downside? How many 8MB bands would there likely be after a boot/shutdown of a VM?