Patch for Samba SamFS Offline Support
ab at samba.org
Thu Apr 3 21:52:01 GMT 2008
2008/4/3, Tobias Oetiker <tobi at oetiker.ch>:
> I have added support for the offline attribute to samba.
> This feature is very useful when using samba in connection with an
> HSM file system like Suns SAMFS. Since Windows Explorer will not
> auto-load headers of files it finds to be marked offline and thus
> refrain from triggering random file retrievals.
> The patch does not have any external dependencies. It figures a
> files offline status by looking at the file size compared to the
> number of blocks it uses on disk. This works for SamFS, but may
> work for other HSMs as well.
> Please find the current patch on
> It would be great if you could include this functionality
> with standard samba.
Current Samba 3.2 (and ctdb-samba 3.0.25) do support offline
operations for systems with DMAPI support (I need to submit two small
patches upstream though for better generic support), this is tested in
production with GPFS and TSM. See modules/vfs_tsmsm.c for details.
When compiled with async i/o, Samba 3.2 with tsmsm module enabled
tries to redirect regular reads/writes to offline file to async
operations, thus allowing a bit of flexibility w.r.t. blocking.
/ Alexander Bokovoy
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