Question about ext3 filesystem for Linux...

[InlineFive]

Hello all.

I want to purchase a Linksys NSLU2 storage unit for our network, which is Windows based. However, I am wondering if it is possible for the ext3 filesystem to have a Windows compatible ACL for files like with NTFS.

Thanks!

-Por

 

[Nothinman]

ext3 on 2.6 kernels supports ACLs via extended attributes. But those ACLs are just normal unix rights, so in order to get NTFS-compatible ACLs you need some munging to happen which I believe Samba takes care of pretty well these days.

But that Linksys thing is a black-box and I've never poked around in it, so I have no idea what kind of things they have enabled. If you don't mind voiding the warranty, take a look at http://www.nslu2-linux.org/

 

[drag]

Yes. Ext3 and a few other filing systems have support for Posix compatable ACLs and they can be utilized thru SAMBA to support NTFS style acls. You can use standard windows tools to change access control lists in SAMBA shares that way without any extra applications...

see here (that's 2 years ago so they would of matured by now)

I don't know much about it. Also Posix ACL does not equal Windows ACL. They are close enough that SAMBA, though, can translate between them.

see this section on from the samba guide.

support for posix acls was added during 2.5 kernel developement and is standard in 2.6, except for NFS which must be patched (from the article I don't know personally). Other Distros backported some support to 2.4

 

[InlineFive]

Thanks for the info people! But now I have more questions:
1. Does POSIX require a full-fledged Linux install or is it self-contained in the file system. As Nothingman so aptly guessed, I would be running this on a Linksys NLSU2 NAS device. And I'm not sure how complete it's version of Linux is.
2. Along the same lines, for POSIX to work does it need to have appropriate user accounts installed to set user permissions? Similiar to Windows?
3. Are there any drivers to let WinXP read and write to an ext3 filesystem? If my NLSU2 broke my laptops would need to be able to work with it 100%.

 

[Nothinman]

POSIX is a set of standards that Linux adheres to in many ways, POSIX ACLs is one of those standards. Most of the support for them will be in the kernel, so it depends on their kernel setup. But you also need Samba to do the Windows sharing and NT ACL translation, I would assume it has Samba because it's supposed to be plug and play with Windows boxes, but who knows how they have it setup.

Accounts again depend on the setup, Samba can be a member of a domain and use those accounts or it can only use local accounts.

There is an ext2 driver for NT that will work on ext3 filesystems, ext2fsd IIRC, it used to be read-only but I believe I heard that they just got write support recently.