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Although neither the webpage nor README explains how it works, I'm guessing it misses a vital Time Machine feature, which is FSLogger. If you have lots of file

Although neither the webpage nor README explains how it works, I'm guessing it misses a vital Time Machine feature, which is FSLogger. If you have lots of files, scanning your whole directory tree every hour is too resource intensive, especially on battery power.

Jedd 7y ago
> Although neither the webpage nor README explains how it works, I'm guessing it misses a vital Time Machine feature, which is FSLogger. I don't know what FSLogger is, and you don't describe the functionality, and you say that you guess that this new free software suite doesn't provide it. Is it something like inotify on GNU/Linux? I do constant backups of 500GB of data via syncthing from my main machines (desktop, laptop) into my archiver, which then uses borgbackup to run an archive / snapshot periodically. Syncthing takes at most a minute to pick up on changes via inotify. Is this the kind of OSX-only killer feature that you're hinting at?
- akvadrako 7y ago
  FSLogger is like inotify but for the whole disk. Inotify is just for files and directories; it doesn't scale to millions of directories. It also would require a full rescan on every boot because installing the watches will take so long you will miss changes. I "guess" because no backup program for Linux supports watching whole filesystems for events. There are ways it could happen with recent kernels, but they are poorly documented and not designed for backups. Nobody has done it so the performance impact is also unclear.
sp332 7y ago
If it were running constantly, it could use inotify. Since this only runs periodically, using rsync to do the scanning is probably the best choice.
- linsomniac 7y ago
  AFAIK, inotify only works on a single directory. You can set it up to add an inotify to newly created directories, but you need to hook into every directory in the filesystem. Unless this has changed more recently, you can't just set up an inotify on "tell me when anything has changed on this filesystem". Some google searches do not indicate that this has changed.
viraptor 7y ago
It delegates all the actual file operations to rsync. In practice, it looks like it does multiple scans each hour - glob on all excluded folders, then running rsync with a big list of excludes for each configured folder. There no clever modification monitoring. I'd keep this away from folders with many thousands of files.
- rastersoft 7y ago
  I'm the author. I doesn't do a glob on the excluded folders, it just passes the list to rsync. Also it changes the priority of rsync, to avoid it using too much CPU.

Jedd 7y ago

> Although neither the webpage nor README explains how it works, I'm guessing it misses a vital Time Machine feature, which is FSLogger. I don't know what FSLogger is, and you don't describe the functionality, and you say that you guess that this new free software suite doesn't provide it. Is it something like inotify on GNU/Linux? I do constant backups of 500GB of data via syncthing from my main machines (desktop, laptop) into my archiver, which then uses borgbackup to run an archive / snapshot periodically. Syncthing takes at most a minute to pick up on changes via inotify. Is this the kind of OSX-only killer feature that you're hinting at?

akvadrako 7y ago
FSLogger is like inotify but for the whole disk. Inotify is just for files and directories; it doesn't scale to millions of directories. It also would require a full rescan on every boot because installing the watches will take so long you will miss changes. I "guess" because no backup program for Linux supports watching whole filesystems for events. There are ways it could happen with recent kernels, but they are poorly documented and not designed for backups. Nobody has done it so the performance impact is also unclear.

sp332 7y ago

If it were running constantly, it could use inotify. Since this only runs periodically, using rsync to do the scanning is probably the best choice.

linsomniac 7y ago
AFAIK, inotify only works on a single directory. You can set it up to add an inotify to newly created directories, but you need to hook into every directory in the filesystem. Unless this has changed more recently, you can't just set up an inotify on "tell me when anything has changed on this filesystem". Some google searches do not indicate that this has changed.

viraptor 7y ago

It delegates all the actual file operations to rsync. In practice, it looks like it does multiple scans each hour - glob on all excluded folders, then running rsync with a big list of excludes for each configured folder. There no clever modification monitoring. I'd keep this away from folders with many thousands of files.

rastersoft 7y ago
I'm the author. I doesn't do a glob on the excluded folders, it just passes the list to rsync. Also it changes the priority of rsync, to avoid it using too much CPU.