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Use of TimeShift for 2 systems

Posted: Wed Aug 15, 2018 1:23 pm
by schmultruc
Hello everybody !

I would like to use the same USB Drive to "timeshitf" 2 different systems (on 2 different computers). I tried to connect my USB drive on the second computer and I was not able to configure Timeshift to have 2 separate paths (one for each computer).
Does anybody know if it is possible to do so ?

Thanks in advance for your help.

Re: Use of TimeShift for 2 systems

Posted: Wed Aug 15, 2018 6:35 pm
by AZgl1500
it is "easy" provided that you do a little bit of extra effort.

I have several different Mint versions using Timeshift to the same /backup partition.

the first Timeshift folder needs to have a text document created inside it, name it 18.3 Cinn ASUS for example.
now, back out of that folder and rename Timeshift timeshift_183_Cinn_ASUS

now, you can go to a different PC and let it run Timeshift, it will create a new folder named timeshift

You must ONLY do Manual Timeshift saves, this will not work for Scheduled timeshift backups.

Note here that I do the same thing for Aptik, for the same exact reason.
Notice there are 4 Timeshift Folders

EDIT: forgot to say that when I do a Timeshift for the ASUS_SSD pc, that I have to rename that folder to timeshift all lowercase.... this is why is so imperative that you put a text document inside the folders to let you know which PC it belongs to.

Image

Re: Use of TimeShift for 2 systems

Posted: Thu Aug 16, 2018 3:06 pm
by schmultruc
Thank you !
I will try your tip very soon.

Re: Use of TimeShift for 2 systems

Posted: Thu Aug 16, 2018 3:21 pm
by gm10
The other option is to create 2 partitions on the drive, one for each system. Configure timeshift accordingly on each system.

Re: Use of TimeShift for 2 systems

Posted: Thu Aug 16, 2018 4:33 pm
by AZgl1500
gm10 wrote:
Thu Aug 16, 2018 3:21 pm
The other option is to create 2 partitions on the drive, one for each system. Configure timeshift accordingly on each system.
In my case, the picture shows a USB 6T HDD, and I did not want to waste partition space just for Timeshift and Aptik.
so, I came up with the renaming scheme.

Re: Use of TimeShift for 2 systems

Posted: Thu Aug 16, 2018 4:42 pm
by gm10
AZgl1500 wrote:
Thu Aug 16, 2018 4:33 pm
gm10 wrote:
Thu Aug 16, 2018 3:21 pm
The other option is to create 2 partitions on the drive, one for each system. Configure timeshift accordingly on each system.
In my case, the picture shows a USB 6T HDD, and I did not want to waste partition space just for Timeshift and Aptik.
so, I came up with the renaming scheme.
Sure. If you go that route consider adding a boot-time script that checks if there's a /timeshift-XXX folder (or just use /timeshift-`uname -n` to make the script portable, have to name accordingly then), if yes rename any existing /timeshift folder back to its installation-specific name (based on a file you place inside like you already did, for example), and then rename the /timeshift-`uname -n` to /timeshift. That way always have the correct folder available right from the start plus you can use scheduled timeshifts.

Theoretically it would be even better to just symlink the correct folder at boot no matter what, that saves you all the renaming, but I haven't tested if timeshift works correctly with a symlink (it should but you know what they say about assumptions).

Re: Use of TimeShift for 2 systems

Posted: Thu Aug 16, 2018 5:59 pm
by AZgl1500
gm10 wrote:
Thu Aug 16, 2018 4:42 pm
AZgl1500 wrote:
Thu Aug 16, 2018 4:33 pm
gm10 wrote:
Thu Aug 16, 2018 3:21 pm
The other option is to create 2 partitions on the drive, one for each system. Configure timeshift accordingly on each system.
In my case, the picture shows a USB 6T HDD, and I did not want to waste partition space just for Timeshift and Aptik.
so, I came up with the renaming scheme.
Sure. If you go that route consider adding a boot-time script that checks if there's a /timeshift-XXX folder (or just use /timeshift-`uname -n` to make the script portable, have to name accordingly then), if yes rename any existing /timeshift folder back to its installation-specific name (based on a file you place inside like you already did, for example), and then rename the /timeshift-`uname -n` to /timeshift. That way always have the correct folder available right from the start plus you can use scheduled timeshifts.

Theoretically it would be even better to just symlink the correct folder at boot no matter what, that saves you all the renaming, but I haven't tested if timeshift works correctly with a symlink (it should be you know what they say about assumptions).
I left out something very important, it is a extUSB HDD that is only plugged in to make backups manually.

each PC looks for its' own timeshift folder and finds it, providing that I remembered to rename it in advance.

Re: Use of TimeShift for 2 systems

Posted: Fri Aug 17, 2018 8:32 pm
by Quetzal
Wouldn't it be sufficient just to identify each backup (as you make it) by adding the computer ID to the 'comment' line in the Timeshift snapshot list (as that's what I do).

All my Linux Mint 18.3 backups from 2 laptops, 1 desktop and one 64GB USB stick go to a single 'timeshift' folder on a 200GB external USB HDD. All the individual backup folders inside it are auto dated and timed as they are created and the same data is shown in the IDENTICAL Timeshift app snapshot list on EACH source computer, but only the snapshot list shows WHICH computer produced THAT backup.

My machines are all using LM18.3, but I don't think it would it matter if they were running different flavours of Linux (as the OP stated in his post) would it? - (Since they're all using the same Timeshift app).

Re: Use of TimeShift for 2 systems

Posted: Fri Aug 17, 2018 8:56 pm
by AZgl1500
Quetzal wrote:
Fri Aug 17, 2018 8:32 pm
Wouldn't it be sufficient just to identify each backup (as you make it) by adding the computer ID to the 'comment' line in the Timeshift snapshot list (as that's what I do).

All my Linux Mint 18.3 backups from 2 laptops, 1 desktop and one 64GB USB stick go to a single 'timeshift' folder on a 200GB external USB HDD. All the individual backup folders inside it are auto dated and timed as they are created and the same data is shown in the IDENTICAL Timeshift app snapshot list on EACH source computer, but only the snapshot list shows WHICH computer produced THAT backup.

My machines are all using LM18.3, but I don't think it would it matter if they were running different flavours of Linux (as the OP stated in his post) would it? - (Since they're all using the same Timeshift app).
as I reread this, you have made me wonder a bit....
Will definitely give this some more thought, AFTER, my jawbone recovers from the Tooth Deamon, she wacked out two molars on Thursday :( and I don't feel so good right now.

Honestly, I never thought to make the ID any different "per PC", that just might work, IF, it keeps a separate record for each PC. if it does NOT, then it will NOT work, as each PC, will be used at different times.

But, the recovery processs "should work" on each PC to bring them all up to the "current status" of the latest one.

The bugaboo that I see, is that PC3 got a "latest and greatest" install of some app, and it was used for a week or two.

then PC #1 is fired up, and it is 3 or 4 timeshift's older, and you decide to make a new timeshift on it... that PC #1 is going to be considered as the basis of how timeshift views the backup, and it will overwrite what is in the backup file....

this is a supposition based on the fact I don't know if "timeshift" compares the backup file, to the PC being backed up, and what it will do to PC #1 if it is missing a lot of stuff while the backup file is for a much later update???

To me, this is dangerous.
PC1 might have kernel 1.1.1.1
PC2 might have kernel 2.2.2.2
PC3 might have kernel 3.3.3.3

and each of those kernels may have different network drivers based on the hardware they are on.

for now, I prefer my method of totally separate Folders being renamed to the PC in use.
I will study what you say later, when I can make my head focus longer than 1 minute.

Re: Use of TimeShift for 2 systems

Posted: Fri Aug 17, 2018 9:39 pm
by Quetzal
Well I'm only talking of 'manual' backups of course, as - though I COULD do unattended auto backups, I wouldn't be able to identify which machine had made them without that identifying note in the comment line.

It seems though that if I make a manual backup on one computer the other computers DO list the new backup (and note) in their own Timeshift apps when I next open them.

edit - I suppose I COULD identify it though as I would only have had 1 computer connected to the USB HDD at a time - unless I later connected it to a different computer without checking. - Think I'll just stick to manual updates!

Re: Use of TimeShift for 2 systems

Posted: Sat Aug 18, 2018 2:40 am
by gm10
Quetzal wrote:
Fri Aug 17, 2018 8:32 pm
Wouldn't it be sufficient just to identify each backup (as you make it) by adding the computer ID to the 'comment' line in the Timeshift snapshot list (as that's what I do).
[...]
My machines are all using LM18.3, but I don't think it would it matter if they were running different flavours of Linux (as the OP stated in his post) would it? - (Since they're all using the same Timeshift app).
It does matter though. timeshift/rsync work like this: When you make the first snapshot then all eligible files from the source system get copied to the backup location. When you create the next snapshot, then only files that were changed actually get copied, for the rest it just creates references (hardlinks) to the previous snapshot. This keeps the additional snapshots fairly small. If you were to now create a snapshot for a different system into the same location, then you'll basically be creating a full first time snapshot every time.

The question is purely efficiency and disk space though. Your actual snapshots will work no matter what, as long as you keep tagging them correctly. It's just not a good idea.

Re: Use of TimeShift for 2 systems

Posted: Sat Aug 18, 2018 3:21 am
by chrisuk
Quetzal wrote:
Fri Aug 17, 2018 8:32 pm
Wouldn't it be sufficient just to identify each backup (as you make it) by adding the computer ID to the 'comment' line in the Timeshift snapshot list (as that's what I do).

All my Linux Mint 18.3 backups from 2 laptops, 1 desktop and one 64GB USB stick go to a single 'timeshift' folder on a 200GB external USB HDD. All the individual backup folders inside it are auto dated and timed as they are created and the same data is shown in the IDENTICAL Timeshift app snapshot list on EACH source computer, but only the snapshot list shows WHICH computer produced THAT backup.

My machines are all using LM18.3, but I don't think it would it matter if they were running different flavours of Linux (as the OP stated in his post) would it? - (Since they're all using the same Timeshift app).
I can't see that giving you incremental backups... Timeshift checks that the UUID of the source drive matches the UUID in the info.json file in the /timeshift/snapshot/<dateandtime> folder created last. If the UUIDs don't match, Timeshift does a full backup, not incremental.

An example:
  • Install to an external drive - check it out - add programs etc. Backup (full, including root and user homes) using Timeshift.
  • Restore that snapshot to different hardware, maybe internal HDD.
  • Make a few changes... do another backup to the same Timeshift partition/folder
Because the UUIDs won't match (unless you change it manually), Timeshift will do a complete backup, not incremental (you'll see the "new files" increasing, but "changed files" staying a 0). So either change the UUID to match, or edit the .json file to match the UUID of the new system.

(As I've mentioned many times in other threads; I only ever do one install of an OS, then use Timeshift to clone to other hardware. I've been doing it this way for years, long before Mint started incorporating Timeshift. I rename folders as already described above by @ AZgl1500.)

Re: Use of TimeShift for 2 systems

Posted: Sat Aug 18, 2018 10:40 am
by Quetzal
Thanks for your views all,

On reflection I was a bit unsure of my assertion last night that changes to one snapshot list were then reflected in all the others that were saving in the same ext HDD folder, so started making backups on different machines to check.

This was about 3am here and things went rapidly downhill after pulling out the HDD USB plug a couple of times without dismounting first, and then losing some backups and deleting some backups direct from the folder (as root), confusing one backup with another etc until I started rapidly losing the will to continue. - Living I mean!

Anyway I jacked it in, went to bed and now intend to purge Timeshift from all 4 machines, make 4 partitions on the ext HDD, reinstall Timeshift and point individual machines to their own separate partitions for RSYNC backups. Also might give each machine its own local BTRFS backup just to check it out.

Onwards and upwards - I hope!