[slagfart]

Perhaps not strictly on-topic, but is there any equivalent FS/program in Windows that will allow users to have read-only access to files that are deduplicated in some way?

My use case is the MAME console archives, which are now full of copies of games from different localisations with 99% identical content. 7Z will compress them together and deduplicate, but breaks once the archive exceeds a few gigs.

These archives are already compressed (CHD format, which is 7Z + FLAC for ISOs), but it's deduplication that needs to happen on top of these already compressed files that I'm struggling with.

Sorry for the off-topic ask!

[storedbox]

You could use a [WIM image][1]. They can be mounted rw or ro and have file-level deduplication. Microsoft's official tooling is necessary to mount them on Windows as [the only open source implementation I am aware of][2] uses FUSE for mounting.

[1]: https://en.wikipedia.org/wiki/Windows_Imaging_Format [2]: https://wimlib.net/

[dashgreen]

If you are using windows server, data deduplication[1] is available on non-system volumes to do exactly this.

If you're using a Windows client, there is a way of enabling this, but it's not exactly supported, for a variety of reasons.

[1]https://docs.microsoft.com/en-us/windows-server/storage/data...

[rakoo]

It's probably a hack, but you can try "backing up" your files with bup, restic or borg, and mount the resulting snapshot with FUSE

[aidenn0]

You probably need to de-duplicate before compression, at least for many compression schemes.

[robbyt]

s/ask/request/g