Post #1181796
2026-04-09 18:48 UTC
Problem: Mac HFS+ format can NOT handle drives 24 TB and larger without issue!
Solution: Use APFS for drives 24 TB and up.
https://medium.com/@kivancgunalp/hfs-cannot-properly-handle-24tb-volumes-on-macos-a-cautionary-tale-1dddd1331e51
I just found out about this.
TL/DR: Mac OS HFS+ format uses 32 bit addressing, and is not capable of error-free formatting of drives.
Apple's new APFS is 64 bit, so solves the issue.
Replies (1)
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@morst@toad.social 2026-04-09 18:48
Why This Happens: "HFS+ was designed in 1998 and uses 32-bit block addressing internally. On very large volumes, the extended attributes B-tree node placement calculations produce an invalid node at a specific location — node #61432 on 24TB volumes — that fsck cannot read. This is a fundamental arithmetic limitation of HFS+ with modern large drives, not a hardware or cable issue."