re: [rdiff-backup-users] ACLs/EAs (who is the audience?)

[Greg Freemyer]

Ben,

 >>  What kind of ACLs or EAs does Samba support?  POSIX(-like?) ACLs and
 >>  no EAs?

I believe samba only supports Posix ACLS.  NTFS also supports a few non-posix 
ACLs and I believe has EA support.

So if cygwin is a target, and full support is desired, I think you need to 
target the full NTFS ACL/EA list.

If only Samba exported filesystems, then you have reduced requirements.

I personally would like the flexibility to use rdiff-backup in both manners.

 >>  In general it would be nice to know why people need (currently or in
 >>  the future) ACLs and EAs, and what platforms they need them on.  I'm
 >>  guessing that the most common configurations are:

 >>  1.  Linux - doesn't support ACLs/EAs now but will with 2.6, at which
 >>  point hackers will start using them for tons of random stuff.

True of vanilla kernels and of the Redhat distribution.

Mandrake, SuSE, and now United Linux all have ACL/EA support patched in.  (see 
http://acl.bestbits.at/)

Also anybody with the XFS patches from SGI has ACL/EA support.

This is specifically why I choose the SuSE distro in preferrence to RH.

 >>  2.  MacOS X - Do MacOS files still have resource forks?  If they do,
 >>  are they accessible through a EA interface (e.g. getxattr())?

 >>  3.  Various other platforms (Solaris, OpenBSD) which support POSIX
 >>  ACLs but not EAs.  These are generally used by system
 >>  administrators to solve complex permission issues.

 >>  Does this sound right?  How does Samba fit in?  Also,

If you pass in --use_acls on the .configure line, samba looks for a posix 
compliant library and uses it.

 >>  4.  Where ACLs and EAs are concerned, is a simple backup all that is
 >>  required, or would it be much more useful if the mirror files had
 >>  all the ACLs correctly mapped?

ACL/EA support varies greatly between filesystems, so the only way to fully 
mirror ACL/EA info is to require that you have the same FS on each end.

FYI: Even worse, the xfs release from a year ago only supported 12 EAs I 
believe.  The current release supports 25 I believe.  So your going to have to 
require the same FS and FS release.

Any attempt to mirror ACL/EAs will also likely be the source of lots of bug 
reports and other confusion. 

Even if that is your long term goal, it seems like overkill for an initial 
release.  

 >>  -- 
 >>  Ben Escoto

Greg
-- 
Greg Freemyer