mergerfs

Adding to the chorus of responses here: I did what this article suggested for a time, but found a purpose-built NAS was way nicer than repurposing an old gaming PC. Using an old gaming PC for a NAS is kind of like trying to use an old track car that you've taken out the interior, added in a roll cage, and welded the doors shut as your kid's first car. Like yeah it will totally work, and they can impress all of their friends as they cosplay as the Dukes of Hazzard, but it's really not optimal for the task at hand. I just upgraded my NAS setup to a Terramaster F4-425 Plus (running Debian) and it's great. The N150 CPU in it sips power, and the whole thing is tiny and easy to hide away in a media cabinet. One ultra-quiet Nocuta fan is all that's needed to keep it cool. It's so nice to use the right tool for the job. EDIT: I'd recommend all of

I use mergerfs + snapraid on my HDDs for “cold” storage for the same reason: noise. Snapraid sync and scrub runs at 4am when I am not in the same room as the NAS. The drives stay spun down 99% of the time, because I also use a ZFS mirrored pool on SSDs for “hot” files, although Btrfs could also work if you're opposed to ZFS because it's out of tree. Basically using this idea, but with straight Debian instead of ProxMox: https://perfectmediaserver.com/05-advanced/combine-zfs-and-o... I also use mergerfs 'ff' (first found) create order, and put the SSDs first in the ordered fstab list of the mergerfs mount point. This gives me tiered storage: newly created files and reads hit the SSDs first. I use a mover script that runs nightly with the SnapRAID sync/scrub to keep space on the SSDs open. https://github.com/trapexit/mergerfs/blob/master/to

https://github.com/trapexit/mergerfs/blob/master/mkdocs/docs... I do this. One mergerfs mount with an ssd and three hdds made to look like one disk. Mergerfs is set to write to the ssd if it’s not full, and read from the ssd first. A chron job moves out the oldest files on the ssd once per night to the hdds (via a second mergerfs mount without the ssd) if the ssd is getting full. I have a fourth hdd that uses snap raid to protect the ssd and other hdds.

- mergerfs: https://github.com/trapexit/mergerfs - snapraid Not used either but these were 2 options that came up when I was researching few years ago.

Sorry I said unionfs but it's actually handled by mergerfs [1], and it's all automatic. There are a whole boatload of policies [2] to control writes. I use "existing path, least free space". Once a path is created, it keeps using it for new files in that path. If it runs out of space, it creates that same path on another drive. If the path exists on both drives for some reason, my rationale is this keeps most of the related files (same path) together on the same drive. I see there's some newer "most shared path" options I don't remember that might even make more sense for me, so maybe that's something I'll change next time I need to touch it. [1] https://github.com/trapexit/mergerfs [2] https://github.com/trapexit/mergerfs#policy-descriptions

I'm quite happy with the Docker version of Jellyfin on my NAS [1] setup. Snapraid [2] and mergerfs [3] join a bunch of hard drives into an highly available RAID with data corruption protection and backup-light functionality which is great for media libraries. Jellyfin scans the media library and exposes it over a web interface to browsers, media players or the Jellyfin Android app in the same network. If you follow a strict naming convention for media files, Jellyfin automatically gets metadata and subtitles from the internet. [1] https://blog.georgovassilis.com/2022/10/28/my-home-nas-setup... [2] https://www.snapraid.it/ [3] https://github.com/trapexit/mergerfs

Slightly on topic, a nice low maintence (other than a daily/weekly backup/scrub script) option without the need for a specific OS is mergerFS, combined with snapRaid. The main benefit is you can add and remove drives/directories willy-nilly. It's been stable for me for the past 3 years, it just works. https://github.com/trapexit/mergerfs https://github.com/amadvance/snapraid/

Cool tool, but recommend reading the policies [0] section carefully, it did catch me off guard the first time I tried using it. E.g. say you have /a/foo.txt and /b/foo.txt, and you run mergerfs /a:/b /merged Now if you print or modify /merged/foo.txt, it would access /a/foo.txt because the default policy for file access is ff (first-found, as defined during the mount). However, if you run "rm /merged/foo.txt", it would delete it from both /a and /b, because the default policy for unlink call would be "epall" (existing path, apply to all). [0] https://github.com/trapexit/mergerfs#policy-descriptions

I also looked at it a few years ago when I last rebuilt my media server, and ultimately decided the same. I now run SnapRAID [1] with mergerfs [2] and for my use, it's got many benefits over zfs and normal raid setups: I could start from my existing volumes, without having to move any files. I can use my random bunch of varying size disks purchased over several years, and add as needed. I tend to buy a new drive every couple years at whatever cheapest $/GB is, which means usually each drive is 2x the size of the last one I bought. If something catastrophic fails like the system itself, the disks are just normal independent ext4 volumes - I can read them from basically anything. I've had to recover a RAID5 array using replacement hardware before, it's not fun and not something I want to ever have to do at home. [1] https://www.snapraid.it

What do you mean by "distribute writes"? One of mergerfs' primary features has always been it's policies which provide different algorithms for choosing a branch to apply a particular function to. https://github.com/trapexit/mergerfs#policy-descriptions