- Is it possible to set up encryption such that backups are still reasonably fast? I will accept a 25 to 50% degrade in performance, but not a 10x blowup in time to completion.
I have an 4 TB external hard drive, and I would like to use Time Machine on it to backup my 1 TB MacBook Pro (with SSD). The backups will happen manually every couple of weeks or so. Let me stress that leaving the external disk plugged in at all times is not an option.
Apparently I have a few options:
- Normal hard drive, click on "Use Encryption" when connected with Time Machine. (configuration I had until now). Seems way too slow; also, every time I connect it I have to wait for ages until the drive is decrypted and I can actually use whatever is on disk. Way too slow.
- Format the drive and use Mac OS Journaled Extended, Encrypted. This will encrypt the whole drive, as I understand it. But will it be faster than option 1)? How do the encryption of 1) and 2) work together? I am quite confused at this point.
- The third option is to format the drive, use MacOS Journaled Extended (not encrypted) and just use time machine without encryption.
The first time I connected it to TimeMachine, it asked me if I wanted to encrypt the data. I thought "Sure, why not" and agreed. I waited for ages the first time (as it had to back up tons of data). A couple of weeks later I come back to backup again; this time it was about 20 Gb of data. It again took ages, and most of the time it was stuck on encryption.
I left it on the whole night, and the morning it was still encrypting (probably something went wrong in this particular case though, as it was 56% at 23:00 and 57% at 09:00 in the morning). But anyway it takes several hours for the decryption process, then there's the actual backup, and then several hours again for the encryption process. Honestly, I cannot have backups taking a whole day. I need to plug it in, wait 3-4 hours, then go on with my life. If I can do this with encryption, good. Otherwise I will have to remove encryption.