Hi @rbhalla,
Because the Linux tree rooted at / is composed of so many things mounted on other things, care is required on backups, and more so on restores. “findmnt” gives a tree view. If you lack that, “df” or “mount” might help.
Some tools use default filters (Duplicati has some underway) but their defaults might not fit the exact system.
Some tools can remain in one filesystem. Their option name typically refers to filesystem, or perhaps mount.
I’ve also heard of people getting to a desired filesystem without all of the other mounts on top by using a bind mount. For example, maybe one could bind mount / readonly somewhere safe, back it up from there, then fix paths on restore. This would get you a broad backup, and take awhile, but using snapshots like the link from @Pectojin mentions (and can be set up on other filesystems) would probably create a better quality backup.
Any plans to support snapshots on the modern Filesystems (ZFS et. al)?
The “Win32 IO returned 25” text might be mono_w32error_unix_to_win32() translating Linux’s EINVAL number into Windows ERROR_SEEK, then Duplicati reporting errors LXCFS handed it as I assume grep is doing here where you can see the grep excludes proc and sys, then errors in lxcfs/cgroup. Maybe error flow is like yours.
If this sounds reasonable, maybe you can update #3303, maybe including a reference to the discussion here.
Thanks!