DragonFly users List (threaded) for 2010-05
Re: OT: Wikipedia FS comparsion page needs update
:I think we should conduct a slight PR move
:and update  w.r.t HAMMER.
Well, if someone wants to correct it, sure. I haven't made any
edits to wikipedia in a long time so it generally doesn't let me
edit without creating a hassle.
:What can be said about data layout?
:The table at  has following columns:
:? Block suballocation
:? Variable file block size
Each block is indexed via the B-Tree. The block size is variable but
the current implementation limits itself to 16K and 64K block sizes.
Extents are theoretically doable but the current implementation
does not use extents.
Hybrid allocation model. Reserve on write, allocate on flush.
:+ Sparse files
:- Transparent compression
:What are those limitations for HAMMER?
:? Maximum filename length
:? Allowable characters in directory entries (are there exceptions?)
No limitations except for '/' of course.
:? Maximum pathname length
Limited by the OS (typically 1024).
:? Maximum file size
Approximately 2^63 bytes
:Does it support ACLs, Security/MAC labels,
:extended attributes, alternate data streams, forks?
:What can be said about CoW, Block journaling or
:Metadata-only journaling of HAMMER?
:Can something be said w.r.t XIP ?
Infinite fine-grained automatic snapshots.
:I guess HAMMER volume still cannot be shrunk,
:nor can it deduplicate.
No, though dedup is easy to do. There were no takers on the dedup
GSOC project though.
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