Linux Equivalents for Novell's "Filer"? 50
Josh Berkus asks: "One of my clients would love to convert their entire office to Linux. But one thing keeps them tied to a NetWare file server: a little utility called 'Filer' Filer allows the sysadmins to retrieve deleted and overwritten files, up to a week after the event. With 70 secretaries using that server, that ability is crucial. I've looked around the Internet, but cannot find anything quite equivalent in the Linux world, except maybe hourly backups and that's a pain. What the client really needs is a utility/mod for the filesystem or network layer that archives files instead of over-writing or deleting them. I had one kernel hacker offer to write me something like that, but my client does not want to be a test case. Note, that we have nothing against Netware, it's just that this client has historically not been able to get good Novell support. Anybody know anything that's already in production like this? Is Reiser working on this for ReiserFS?" This sounds deceptively easy. If this was a personal machine, this would be easy, but the showstopper is that this has to work as a share meaning that this "trashcan" like functionality needs to be implemented at the filesystem level. While I can understand the submittors desire to not be a test case, if there doesn't exist a ready-made solution to this particular problem, how difficult would it be to add this on to ext2/ext3, Reiserfs or some other suitable open source filesystem and test it for reliability?
Ahhh. Salvage. (Score:5, Interesting)
Salvage, the feature's proper name, is a tremendously powerful feature of Netware. Basically, when files are deleted from Netware volumes, they are not truely deleted. They are unlinked or renamed and become invisible to the clients but, the deleted files remain on the Netware volumes. When the Salvage utility is invoked, these files can be displayed, selected and instantly restored.
Deleted files remain on the volume until the volume runs "out of space", at which time the oldest deleted files are automatically purged as necessary to allow space for new files. It is important to note that the space consumed by deleted files is not reflected in any of the client utilities and does not count in disk quotas. This means that from the clients perspective the volume will show that there are 30 Gigs free despite of the fact that the volume is in fact full, due to deleted files.
Another interesting note is that deleted files retain their rights attributes. Files invisible to a certain user cannot be seen or restored by that user if they are deleted. Only users that had the appropriate rights before the file was deleted can manipulate these deleted files.
The deleted files can also be purged manually from individual directories or the entire volume. Purging can also be configured to purge the deleted files immediately which is the recommended configuration of temp directories.
This beloved feature of Netware has always been admired. The user community has always requested it in other OSes but, as yet, the only thing to even come close is an NT/2000 add-on called Network Undelete, from the folks at Executive Software, the same people that brought us Diskeeper. Unfortunately, it's still not quite the same.
Several posts have stated that this should be a simple thing to implement. I cannot speak to the ease or difficulty of implementing this feature. However, one does have to wonder how easy it would really be. Considering that Salavge is such an old feature on Netware, that there have been so many requests for it in other OSes and yet Netware is still the only OS to offer it, one must conclude that it is not really so easy to implement.
If you have found a developer that is willing to try to implement such a feature, I strongly encourage you to get them going, regarless of whether you want to be a test case or not. The community would love and appreciate this feature in Linux and any other OS.