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I'm new to Linux and found out the hard way about the virtues of keeping a backup I can restore my system from. So I am trying Timeshift and have some questions about what's going on under the hood.

Some web articles about Timeshift say backups share common files to save disk space. I've made two snapshots with no real changes to my system. My file system says the first snapshot is about 8GB in size, and the second is about 8GB in size, and both are about 16GB in size.

Question 1: If Timeshift really does share common files to save disk space, is there some way I can get the true size of these backups? I'm expecting the first backup to be 8GB, and the second to be only a few megabytes.

Question 2: If Timeshift does save diskspace by sharing common files, if I delete the first backup, will files "linked" to the second backup appear to become deleted, but really they are not because the second backup is now "claiming" them?

Question 3: In other's experience, can I rely on Timeshift to produce a proper restore of my system if I include my home and root files too in the backup? I did a test restore before venturing too far with my new system, and everything seemed to be fine.

Question 4: It looks like installing Timeshift added a duplicate filesystem partition mirroring my extended partition. Both partitions show about 1TB in size on my 1TB drive. I did uninstall Timeshift and reboot to see if that duplicate filesystem partition would go away, but it didn't. Is there a way to safely remove that Timeshift filesystem partition if I decide to stop using Timeshift?

Thank you very much,

Kevin

Kevin Berry
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  • Are you using BTRFS or rsync mode? It matters quite a bit as far as how it works. Did you read through the developer's page on how it works? https://github.com/teejee2008/timeshift – Organic Marble Mar 17 '21 at 18:56
  • I'm using rsync. I read the developer's page. As a side note, my snapshots are saving pictures and everything else in Home, so I don't know why some pages such as this one say to use something else to backup personal data. Personally, I wouldn't want to use a snapshot tool that wouldn't also backup personal data. That's more important to me than the system, and more convenient for me when a snapshot tool can grab both. – Kevin Berry Mar 17 '21 at 21:01
  • I use clonezilla. – pierrely Mar 18 '21 at 05:14
  • For what it's worth, `timeshift` is for system files and it's used to back up the system. If you want to back up your home directory and data, I suggest you consider `rsnapshot`. It doesn't answer your question since the principle behind it is about the same as `timeshift`. – Ray Mar 18 '21 at 10:38
  • Thanks very much for contributing to my education here. I did look at clonezilla and rsnapshot and they look great for different reasons (actual clone, fine tuned backup). I also discovered as explained below I don't want to routinely backup system and personal data together anymore because restoring one or the other affects both. Thanks again! – Kevin Berry Mar 18 '21 at 17:31
  • So my backup strategy now is to use TimeShift for system and personal data. After a timeshift restore, I can restore what's needed from a personal backup just using rsync directly. (rsync -aAXv /home/kevin/ --exclude={"/.local/share/Trash/","/Videos/"} "/media/kevin/MyHDD/Home Backup") -- from another post. I decided against Deja Dup to backup personal data because it compresses everything. I want to be able to grab just what I know I need. – Kevin Berry Mar 19 '21 at 15:39
  • That backup post for using rsync directly came from here: https://ostechnix.com/backup-entire-linux-system-using-rsync/. I use the command above to make the backup, but can cherry pick what to manually put back over a Timeshift restore such as email. – Kevin Berry Mar 19 '21 at 15:46

1 Answers1

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Q1: I have about a dozen TimeShift snapshots on my system. They definitely share files.

Q2: You should only delete backups using the application itself. That ensures the integrity of each snapshot.

Q3: TimeShift will create a snapshot of home if you configure it to do so. However it is a snapshot. That means if you restore from a week ago, for example, you will get exactly that. Any changes you made in home, edits of documents, new photos etc... will be overwritten and probably lost. I’m pretty sure new files will be deleted if they were added since the snapshot.

Q4: TimeShift mounts your save destination to a particular location in the file system. That means it can look like it’s duplicated but it isn’t. Just after a reboot it probably will not be mounted like that so I suggest you check. Again use the application itself to remove all backups if you choose to.

For the record I have used TimeShift for a couple of years and it has always worked perfectly. I did have an issue once when a change to another package created an infinite loop of files to backup but that was not the fault of TimeShift. I highly recommend it but if you do backup home just be conscious of what will happen.

PonJar
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  • Thank you for explaining how Timeshift works. I'll just accept the disk storage works as you say it does and as advertised. However it works, I need it. It just saved me again after doing an "apt autoremove" -- after turning off getting "recommended packages" in an apt config file -- took out too much of my system. As you cautioned, I did lose my email for the last 12 hours, but I had gone through that fortunately. I now understand why keeping personal data separate from system data is important, and will keep the backups separated now. Thanks again! – Kevin Berry Mar 18 '21 at 17:18
  • If you are happy with the answer please accept it so that others will be able to find it more easily. – PonJar Mar 18 '21 at 23:06
  • Thanks again! I appreciate your time helping me out. I'm very at ease using Timeshift now. – Kevin Berry Mar 19 '21 at 14:19
  • Which Ubuntu paths would you recommend Timeshift DOES and which paths it should NOT track/snapshot? /opt, /etc, /boot etc – user997112 Aug 13 '23 at 06:58
  • The defaults are recommended. The objective is to have the ability to fix the system by going back to a known working snapshot. Basically any path that holds system files but not home – PonJar Aug 24 '23 at 17:58
  • Steam places some apps in home. If you want to restore those then some or all of home can be included – PonJar Aug 24 '23 at 18:01