Comment on When using rsync to backup my /home folder to an external 1TB SSD, I run out of space, how??
bleistift2@sopuli.xyz 13 hours ago
Could it be you have lots of tiny files and/or a rather large-ish block size on your SSD?
You can check the block size with sude blockdev --getbsz /dev/$THE_DEVICE.
sbeak@sopuli.xyz 12 hours ago
using the command returns 512 for the external SSD and 4096 for the SSD in my laptop. What does that mean?
bleistift2@sopuli.xyz 12 hours ago
Imagine your hard drive like a giant cupboard of drawers. Each drawer can only have one label, so you must only ever store one “thing” in one drawer, otherwise you wouldn’t be able to label the thing accurately and end up not knowing what went where.
If you have giant drawers (a large block size), but only tiny things (small files) to store, you end up wasting a lot of space in the drawer. It could fit a desktop computer, but you’re only putting in a phone. This problem is called “internal fragmentation” and causes files to take up way more space than it would seem they need.
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However, in your case, the target block size is actually smaller, so this is not the issue you’re facing.
SlurpingPus@lemmy.world 12 hours ago
Means a file that’s 512 bytes in size will take 512 bytes on the external disk, but at minimum 4 KB on the internal one. If it were the other way around, that would partially explain the difference in space used.
In any case, I doubt it that the block sizes would make so much difference in typical usage.