Is it possible to stipulate a blocksize for a disk?

Is it possible to specify a smaller blocksize for disks?
I’m using Raid 1, but storing a lot of small files 18.5k files, 588Mb size, but 18.4Gb on disk (on a SMB share)

Cheers

Carl.

@carl
quick question, if you run the below commands:
fdisk -l,
btrfs fi show
and
btrfs fi df /mnt2/<yourShareName>
or
btrfs fi usage /mnt2/<yourShareName>

what do those numbers show? Since the “actual usage” is always a mix of the RAID setting, meta data and system data on the system, could it be that your actual storage is fairly close to the half Gig you mentioned vs. the metadata consuming all the other space?
Maybe you’ve already gone through all that …
In my case, e.g. the logical/phyical sector size is: 512/4096 bytes, and without being the expert I suspect, if you were to force the sector size smaller (using the command line btrfs) you would still not receive a substantial reduction in space.

Finally, I believe, there is a sectorsize parameter where you can muck with that setting, but it seems also rather sensitive to other circumstances that could result in an unmountable file system. I guess, the other option could be to experiment with compression levels to see whether that has any benefits (or using LUK, but that might be overkill).

A little older, but I like this compare/contrast on filesystems’ handling of data (again, might be all old news to you, but for the uninitiated could be of interest):
https://ownyourbits.com/2018/05/02/understanding-disk-usage-in-linux/

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