[SOLVED] NTFS Operation Not Supported (45)

Ewok, as requested I have opened case number 13156877.

Over the last couple of days I've been working with the developers at Tuxera to try to investigate this problem. The full thread of what we tried is here:
http://tuxera.com/forum/viewtopic.php?f ... 4f2#p20447

Here's the summary
Frontview provides two ways of backing up to a USB NTFS drive:
1) cp -p
2) rsync -aVA

Note that both commands attempt to preserve permissions. Both commands work fine when copying any file that has only the standard UNIX file permissions and no ACLs. However, in the case of a file with ACLs, both commands fail when writing to an NTFS filesystem mounted by the ReadyNas. This is because RAIDiator 4.1.6 is not properly set up to be able to copy ACLs to an NTFS partition.

The easiest way I have found to solve the problem is to set the Samba option

nt acl support = no

for each share defined in the Samba configuration file /etc/frontview/samba/Shares.conf. Samba can be forced to re-read this file by

 /etc/init.d/samba restart

The effect of this setting is that Samba will ignore applications like Microsoft Word that attempt to modify ACLs. This means that the ext3 share will never get into the situation where it has any files with ACLs. Therefore all files will still have the standard UNIX file permissions, but there will be no ACLs. This means that the backups now function without any errors (even with the -p or -A options).

The problem I have not been able to solve is that as soon as the Readynas is rebooted, this config file is overwritten and the settings are lost. I would be grateful if you could let me know how I can make the setting survive reboots.

Of course, the ideal solution would be for RAIDiator to be properly set up to copy ACLs to NTFS (so that permissions are just as complete as when using ext3). There are a few things preventing error-free copying of ACLs in RAIDiator 4.1.6:
1) The version of ntfs-3g is too old (it needs to be updated to 2010.8.8 or later)
2) By default, ntfs-3g does not include ACL support. In order to build it in you must configure with the compile time option "--enable-posix-acls". As far as I can tell, there is no harm from setting this option even if it's not immediately used (it will only take effect of item 4 is also performed - see below).
3) In addition to the above, the Linux kernel must be at least 2.6.20 (see http://www.tuxera.com/community/ntfs-3g-faq/#fuse26) so that a decent version of FUSE is incorporated
4) In the root directory of the NTFS drive (I think this can also be configured to be elsewhere if desired) there must be a directory ".NTFS-3G" and within that directory a file called "UserMapping" containing the line

::S-1-5-21-3141592653-589793238-462643383-10000

A reboot seems to be required for this to take effect. In the ideal case the file would contain a Microsoft SID -> Unix UserID and GroupID mapping for every PC user account. This way the drive could be disconnected from the ReadyNas and moved to any PC and permissions would be perfectly maintained.

During this investigation I updated the NTFS-3G driver to 2010.8.8 with POSIX ACLs enabled (from here viewtopic.php?p=257923#p257923). This also had the nice side benefit of boosting NTFS write performance by 39% (viewtopic.php?p=258033#p258033). I have a ReadyNas X6, and on models with more powerful CPUs (NV+) the performance improvement seems to be higher.

As I mentioned before, it would be great if you could let me know how to make the "nt acl support = no" permanent.

Thanks and regards,

Mark