I currently use an external back-up disk, with Time Machine, to back-up my entire iMac. I now need to move my Lightroom photo library to an SSD external drive. Can I back-up this SSD drive on my external back-up drive using TM?
Yes. To reassure yourself open Time Machine's Settings and click the Options button. The external drives should not appear in its exclusions list. The TM backup drives themselves will be "greyed out" and not selectable because they are the only items excluded by default.
I have two and I keep one in the safety deposit box at the Bank and switch them every two months.
That's a good strategy. You can have as many TM backup drives as you wish.
Yes. To reassure yourself open Time Machine's Settings and click the Options button. The external drives should not appear in its exclusions list. The TM backup drives themselves will be "greyed out" and not selectable because they are the only items excluded by default.
I have two and I keep one in the safety deposit box at the Bank and switch them every two months.
That's a good strategy. You can have as many TM backup drives as you wish.
I'm not sure if I am interpreting your question correctly, but by default, Time Machine backs up all mounted volumes, internal or external, assuming they are mounted when Time Machine runs.
It absolutely will. You did not provide your specific iMac model, but all recent ones have very fast USB connections that are capable of transfer speeds equal to their internal storage (again, assuming yours is a recent Mac). The cable is a critical component so be sure you use a correct one: Use caution when purchasing USB-C cables: they are not all alike. - Apple Community
I recommend that you peruse OWC / MacSales for external SSDs and related products that are certain to work with whatever Mac you have. Avoid PC-centric vendors.
The speed of the Time Machine backup drive is less important. The "overhead" required in backing up completely obviates the speed advantage of SSDs. That's why I advocate getting at least two TM backup disks. They're cheaper than SSDs. When they fail, throw them out. Besides, unlikes SSDs that tend to fail catastrophically, HDDs usually give plenty of warning before failing completely.
I believe you did. So if I have my external SSD drive, which contains my photos library, connected at the time of the back-up Time Machine will automatically back-up the data residing on the external drive? I think the confusion comes from the fact that I use an external back-up drive to make my back-ups. I have two and I keep one in the safety deposit box at the Bank and switch them every two months.
That's great. Thank you so much for a quick answer. I have not bought the external SSD drive yet. I wanted to be sure I could back it up with Time Machine. Since you are so helpful do you have a recommendation? I'm looking to buy a 4TB SSD external drive as I use Lightroom and several more photography tools which are heavy. I'm thinking SSD will provide faster transfer and read speed. Your thoughts?
I have a 2019 iMac with 2 tb of SSD drive. But it has USB-C connection. I have purchased adapters for USB 2.0 as needed by external devices. I presume these adapters are not recommended to use with an external SSD drive so as not to impact speed. Correct?
[Edited by Moderator]
Correct. That iMac has two Thunderbolt 3 ports which can transfer data at speeds up to 40 GB/s. So if you want maximum performance find an external SSD compatible with that protocol (OWC has them).
That iMac also has USB 3.0 ports that can transfer data at a theoretical maximum speed of 5 GB/s... still very fast, and are more than likely to be acceptable.
USB 2.0 would limit that speed to 480 MB/s... abysmally slow by comparison. Ok for Time Machine backup drives though.
You have been amazingly nice to respond to all of my questions. I will search for OWC with USB 3.0 port compatibility. I have one last question. How would I located the external SSD drive if I needed to go to Time Machine to retrieve some data? Is it easy to identify?
Would this one do the trick?
That's a fine choice, and B&H is a reputable vendor.
Thank you so much for your help. It was greatly appreciated.
Time Machine back-up with external drive
