hard drivemacosperformancetime-machine
I got myself this WD 2TB USB3 external harddrive for backups: http://amzn.to/1X8b3a8
I connected it to the USB 3.0 port of my mid 2015 Macbook Pro 15".
When I run Time Machine, it really takes veeeery long for the backup (about 10-20 hours for a 350 GB initial encrypted backup).
So I ran disk speed test with this result. Is this speed normal and does Time Machine backup really take that long?
The answer is this isn't easily done. Apple doesn't expose the timing which means it's likely to change if you apply any updates to the system or the change might even break backups so they don't run.
I've left a comment asking about the use case. I've employed scripts to get around this in several cases for customers, but I'd need to know more about your actual use case before providing an alternate solution that would work even with the default Time Machine scheduling.
Time Machine performs versioning backups at specific time intervals and keeps making backups until it runs out of space on the drive, then it starts to prune away older backups to make room for the new ones.
The only way that I know of to control the amount of space that any one Time Machine Backup uses is to set up a partition on the drive in Disk Utility and then have Time Machine back up to that partition.
You will not be able to delete some of the time machine backup as it is stored like a database, and it is an all or nothing delete.
Response to Trash Question
If you have 1.2MM files, Secure delete will take a very long time to do this.
If you do not mind that the data will not be overwritten and only the file associations will be removed you can do this to clear out the Trash.
First of all BE INCREDIBLY CAREFUL WHEN USING RECURSIVE DELETE FROM TERMINAL
With that warning out of the way, here is how you can do it.
EDIT step two is for the trash bin in your user directory. Yours is likely on the root of the drive itself. As I don't know what that path will be I can't give you that step. Just replace that path for the one after cd. The file is likely hidden, so if you do not know how to show hidden files I will add the Terminal commands at the bottom of the post.
FROM user3439894 use sudo rm -fR /Volumes/<volume_name>/.Trashes/$UID/*
This will be what the path to your external drive's trash looks like. You will have to figure out the exact path on your drive. You can also skip the drag and drop steps doing it the way user3439894 suggests.
cd ~/.Trash and press Return.sudo rm -Rf followed by a Space (don’t leave out the space). You will need the recursive for to handle subdirectories, etc.rm(remove) command.In a moment or two (depending on how much was in your Trash), the Trash icon should return to its empty state.
-- The answer I provided is based on the technique that I obtained from Joe Kissell's article on MacWorld and have used during the times I have not been able to empty my trash bin.
How To Display Hidden Files In Mac OSX
terminal
defaults write com.apple.finder AppleShowAllFiles true return
killall Finder return
How To Hide Hidden Files in Mac OSX
terminal
defaults write com.apple.finder AppleShowAllFiles false return
killall Finder return
Best Answer
Time Machine and OS X is tuned to throttle the IO and possibly the CPU usage of the backup task. You can do a few things to modify that behavior - but from the speed benchmark and my experience - a 12 to 48 hour initial backup is not abnormal or indicative of slow backups once you have a few intervals backed up.
To do the second, you'll ned terminal and want to review this excellent answer as well as some speculation on the web.
At that point, you would restart your Mac. When it restarts, then erase the USB 3 drive and establish it as the backup destination and start the initial backup again. There's no need to use the
tmutilcommands over the Time Machine preference if you like mouse control or visual feedback over terminal commands. The echo 'debug.lowpri_throttle_enabled=0' command needs to be run in terminal, though.Lastly, you will need to change the removedestination command to command removal of your destination's unique ID instead of DEB58ECE-531B-4295-85B4-82FC905A01EA. Also, you might also see if your current backups are throttled and how they are doing work with:
Unless you're really interested in analyzing the low level performance, I'd say you don't have a problem - just a slow initial experience - and revisit things in a week once the steady state backup timings are known. If you get hourly backups completing in 5 minutes or less - you probably shouldn't disable the debug timings as I listed above.