I haven't been in the habit of making backups because it just seemed too troublesome to decide what to back up and how to do it, I suppose.

The "how" is easily solved if you have an old (or new) Linux box somewhere. (Urbackup server also runs on other Unixes, and on Windows, but I use it only on Linux servers.) Urbackup does not need a lot of hardware. I run it in a Proxmox container at home, with just 2 GBytes memory, 1 GByte swap, and two CPU cores (2.2 GHz each). At work, it runs on an old HP N36L (2x 1,3 GHz, 8 GByte RAM), together with the rsync backup script for the Linux machines. Backup is done on spinning rust, some single-digit TByte desktop harddisks in a RAID-1 or RAID-5. Just don't buy SMR disks, they suck big time. CMR is fine. SSDs, a fast CPU, and much RAM all don't hurt, but aren't really needed. Urbackup is limited by the available network bandwidth, and it is designed to run in background.

The "what" is almost as easy. Because at least pre-UEFI PCs need a master boot record and a boot sector, you want an image backup of your bootdisk. You don't need to have it created very often, because MBR and boot sector are usually constant. And you only need two or three images. It's just to start a bare metal restauration, if things have gone really wrong. The real backup are all files on all non-removable disks in your computer, with the exception of the swap file and the hibernation file. Urbackup will create a few full backups and a lot of incremental backups, and it will automatically clean up old backups. You want to keep incremental backups of at least a few weeks, and full backups for a few months. The full backups takes some time (because they are done in background), but the incremental backups are reasonably fast.

You can tell the Urbackup client to suspend the running backup if you need the full performance of your computer. I do that occasionally when juggling with huge VMs, or when the Urbackup clients tries to backup the files that I currently use.

I have configured Urbackup at home to create an incremental file backup every 24 hours, and a full file backup every 30 days, keeping max. 100 incremental and max. 10 full backups. Incremental image backups run every week, full image backups are disabled, up to 30 incremental and 5 full image backups are kept.

That sounds like a lot of data, but Urbackup deduplicates the data on disk. My boot disk is 240 GByte, and needs about 320 GByte of backup space for images. Together with the 500 GByte data disk (which is almost full), this fills about 1.5 TByte of backup space for images. Included in the file image backup are several large VMs that modify their hard disk images almost daily, so I guess that my file backup is unusually large. (The VM disk images can't be deduplicated.)

Alexander