It is tempting to partition a backup drive so you can use some of that storage space for other things. But you should avoid doing so for two key reasons.
Comments: 17 Responses to “Why You Should Never Partition Your Backup Drive”
Bent, Denmark
1 year ago
Thank you for another instructive video.
I have a 50 GB iCloud storage and have chosen not to include Photos App in my iCloud storage. It will fill up all storage. (I am aware that photos are not synced between devices).
First I wonder if the Time Machine back up to an external drive does include photos in the Photos App.
Secondly I wonder what is the best procedure to back up Photos App-photos to a separate external drive. Making a full backup each time seems to be too much.
Denmark: Yes, Time Machine backs up all of your files. Since your Photos library is a file (a library package) in your Pictures folder, it will back that up too. You can just look and see. If you want to back up to another drive, just drag and drop that Photos Library file to that other drive to make a copy of it there.
Bent, Denmark
1 year ago
Thanks Gary.
Have you considered making a video on how to backup and restore photos placed in the Photo App using the Time Machine
Unlike other files in the external backup made by the Time Machine, individual items within the photo library can not be seen. Apparently the full photo library must be restored. Will such a restore overwrite the existing MAC photo library with the same name or where will it be placed in my MAC file structure?
Denmark: Hopefully, if you accidentally delete a photo and need to get it back you can find it in the Recently Deleted album. If you can't, then you can restore the photos library, but don't have it replace the current library, just appear as a new library in your Picture folder. Then open that library up, find the photo, export it, switch back to your current library, and then import it. Then you can delete the restored old library.
Or, if you are careful and willing to explore, you can look directly on the Time Machine drive, find the library there, use Show Package Contents to go inside, find the image (difficult) and then copy it and paste it on to your regular drive for importing. Just be careful not to move or change anything in the Time Machine drive, just look and copy.
Frank Scully
1 year ago
If Denmark does not include Photos App in iCloud storage, then his photos taken say on an Iphone would not be on his Mac unless he manually copied them there. Hence his backup would not be complete
Donald Cope
1 year ago
After doing a bit more research, I found the following in Apple Support: "Apple File System (APFS) allocates disk space on demand. When a single APFS container (partition) has multiple volumes, the container’s free space is shared and can be allocated to any of the individual volumes as needed." I must have created two volumes in one container (partition). Therefore, my Time Machine (one volume) can use all of the space (4 TB) if I do not use the other volume. Is this reasonable?
Donald: It is reasonable, but I would still avoid it. No reason for that other volume since you shouldn't use it for anything. But I suppose it may not be worth messing with if you already have it set up and just remember not to use it.
Bent, Denmark
1 year ago
Thank you Gary for 3 very good suggestions (recently deleted, restore etc., looking into the Backup library (with care)). And Frank thank you for your “warning”. I am aware of the non-sync situation.
Steve C.
1 year ago
I have a very specific for having 2 partitions (APFS) on my backup drive, which happens to be an external SSD.
- Partition 1 is for Time Machine backups.
- Partition 2 is for ad hoc file and folder backups, e.g. key snapshots and external data from remote development.
I do not store any original content in Partition 2. It's all copies. If I lose the drive I only lose backups.
Steve: Not sure where the files for partition 2 are coming from. From other external drives? If so, just include those external drives in your Time Machine backup. From servers? If so, then why not download the "backups" of those to your main drive, and then let Time Machine back those up as normal. Then you have a history for those files.
Steve C.
1 year ago
Hi Gary,
It's mostly a matter of convenience. I can organize ad hoc backups with named folders to make it easier to find things, compared to the TM app. Some of the files are also backed up in TM, and even iCloud. But I've found the organized key snapshots to be a useful adjunct to TM.
I save known-good source code, so I don't have to remember TM date/time. I also backup cloud dev servers.
I've had TM volumes get corrupted. Don't know if APFS volumes can corrupt each other though?
Steve: I don't know if one volume can "corrupt" another. Probably rarely if ever. More likely that the whole drive goes.
Steve C.
1 year ago
Gary: My instinct too. In any case that second partition only has replaceable and temporary files, e.g. for transport to another machine. The TM volumes that got corrupted were probably spinning disks, not SSDs. I do think the large quantity of filesystem objects on a TM volume does make it more subject to "cosmic rays" and other random damage. Cheers.
Steve: Cosmic rays, no. But power spikes, static electricity, accidentally pulling the cable out in the middle of a write, and just drive parts failure is what you need to worry about.
RJ
1 year ago
I can't seem to find it at the moment but I thought with Time Machine you had the option to have it delete backups if there was not enough space to hold the next backup?
As an alternative to a NAS you can get something like a Western Digital My Book Duo which has two hard drives that can be setup in RAID so if one drive fails the other should have an exact copy. Then you just replace the bad drive with a new drive (has to be the same size disk) and all the data should move to the new drive
George
1 year ago
I like the advice. I have not followed it. But I think not following it makes things very complicated. So I plan to avoid single points of failure by using backup on one partition on one drive once I get more drives.
One thing I like is having two copies of all original data: A and B.
I want to put one set ‘A’ in a safe or safety deposit box, and monthly swap things with ‘B’ so that one is always somewhere else.
But with COVID, the split was hard to do.
Now I can do that split.
Tim
1 year ago
Reason one, of having the drive "split" and running out of space on one partition and needing it on the other is not an issue if using APFS partitions. Given the ability to add a second "Volume" to an APFS partition allows me to have the entire drive available for Time Machine, while still giving me a location to put some large temporary / transient files.
Thank you for another instructive video.
I have a 50 GB iCloud storage and have chosen not to include Photos App in my iCloud storage. It will fill up all storage. (I am aware that photos are not synced between devices).
First I wonder if the Time Machine back up to an external drive does include photos in the Photos App.
Secondly I wonder what is the best procedure to back up Photos App-photos to a separate external drive. Making a full backup each time seems to be too much.
Denmark: Yes, Time Machine backs up all of your files. Since your Photos library is a file (a library package) in your Pictures folder, it will back that up too. You can just look and see. If you want to back up to another drive, just drag and drop that Photos Library file to that other drive to make a copy of it there.
Thanks Gary.
Have you considered making a video on how to backup and restore photos placed in the Photo App using the Time Machine
Unlike other files in the external backup made by the Time Machine, individual items within the photo library can not be seen. Apparently the full photo library must be restored. Will such a restore overwrite the existing MAC photo library with the same name or where will it be placed in my MAC file structure?
Denmark: Hopefully, if you accidentally delete a photo and need to get it back you can find it in the Recently Deleted album. If you can't, then you can restore the photos library, but don't have it replace the current library, just appear as a new library in your Picture folder. Then open that library up, find the photo, export it, switch back to your current library, and then import it. Then you can delete the restored old library.
Or, if you are careful and willing to explore, you can look directly on the Time Machine drive, find the library there, use Show Package Contents to go inside, find the image (difficult) and then copy it and paste it on to your regular drive for importing. Just be careful not to move or change anything in the Time Machine drive, just look and copy.
If Denmark does not include Photos App in iCloud storage, then his photos taken say on an Iphone would not be on his Mac unless he manually copied them there. Hence his backup would not be complete
After doing a bit more research, I found the following in Apple Support: "Apple File System (APFS) allocates disk space on demand. When a single APFS container (partition) has multiple volumes, the container’s free space is shared and can be allocated to any of the individual volumes as needed." I must have created two volumes in one container (partition). Therefore, my Time Machine (one volume) can use all of the space (4 TB) if I do not use the other volume. Is this reasonable?
Donald: It is reasonable, but I would still avoid it. No reason for that other volume since you shouldn't use it for anything. But I suppose it may not be worth messing with if you already have it set up and just remember not to use it.
Thank you Gary for 3 very good suggestions (recently deleted, restore etc., looking into the Backup library (with care)). And Frank thank you for your “warning”. I am aware of the non-sync situation.
I have a very specific for having 2 partitions (APFS) on my backup drive, which happens to be an external SSD.
- Partition 1 is for Time Machine backups.
- Partition 2 is for ad hoc file and folder backups, e.g. key snapshots and external data from remote development.
I do not store any original content in Partition 2. It's all copies. If I lose the drive I only lose backups.
Am I mis-thinking this?
Steve: Not sure where the files for partition 2 are coming from. From other external drives? If so, just include those external drives in your Time Machine backup. From servers? If so, then why not download the "backups" of those to your main drive, and then let Time Machine back those up as normal. Then you have a history for those files.
Hi Gary,
It's mostly a matter of convenience. I can organize ad hoc backups with named folders to make it easier to find things, compared to the TM app. Some of the files are also backed up in TM, and even iCloud. But I've found the organized key snapshots to be a useful adjunct to TM.
I save known-good source code, so I don't have to remember TM date/time. I also backup cloud dev servers.
I've had TM volumes get corrupted. Don't know if APFS volumes can corrupt each other though?
Steve: I don't know if one volume can "corrupt" another. Probably rarely if ever. More likely that the whole drive goes.
Gary: My instinct too. In any case that second partition only has replaceable and temporary files, e.g. for transport to another machine. The TM volumes that got corrupted were probably spinning disks, not SSDs. I do think the large quantity of filesystem objects on a TM volume does make it more subject to "cosmic rays" and other random damage. Cheers.
Steve: Cosmic rays, no. But power spikes, static electricity, accidentally pulling the cable out in the middle of a write, and just drive parts failure is what you need to worry about.
I can't seem to find it at the moment but I thought with Time Machine you had the option to have it delete backups if there was not enough space to hold the next backup?
As an alternative to a NAS you can get something like a Western Digital My Book Duo which has two hard drives that can be setup in RAID so if one drive fails the other should have an exact copy. Then you just replace the bad drive with a new drive (has to be the same size disk) and all the data should move to the new drive
I like the advice. I have not followed it. But I think not following it makes things very complicated. So I plan to avoid single points of failure by using backup on one partition on one drive once I get more drives.
One thing I like is having two copies of all original data: A and B.
I want to put one set ‘A’ in a safe or safety deposit box, and monthly swap things with ‘B’ so that one is always somewhere else.
But with COVID, the split was hard to do.
Now I can do that split.
Reason one, of having the drive "split" and running out of space on one partition and needing it on the other is not an issue if using APFS partitions. Given the ability to add a second "Volume" to an APFS partition allows me to have the entire drive available for Time Machine, while still giving me a location to put some large temporary / transient files.