Opened 9 years ago

Last modified 4 years ago

#63 assigned defect

Support hard links in directories

Reported by: Ben Bennett Owned by: chris
Priority: normal Milestone:
Component: bbackupd Version: 0.11rc2
Keywords: backup duplicate rename hardlink corruption Cc: [email protected]

Description (last modified by chris)

Ben Bennett reported the following warning message:

Jun 21 22:23:42 ayup bbackupd[24222]: WARNING: Found conflicting parent ID for file ID 1579976 (/home/fiji/public_html/pictures/49/014 - Nursery.jpg): expected 34689 but found 69964 (same directory used in two different locations?)

The warning is correct, the file is in two locations...

# ls -li '/home/fiji/public_html/pictures/49/013 - Nursery.jpg' '/home/fiji/public_html/family/3/013 - Nursery.jpg'
1579975 -rw-r--r-- 2 fiji fiji 131622 2002-12-18 07:37 /home/fiji/public_html/family/3/013 - Nursery.jpg
1579975 -rw-r--r-- 2 fiji fiji 131622 2002-12-18 07:37 /home/fiji/public_html/pictures/49/013 - Nursery.jpg

Chris Wilson said:

I agree that hard links should be supported, and that this is a bug. Please could you get an account in the bug tracker and file a bug?

The reasons for this warning are:

  1. Almost nobody uses hard links on their data files, so nobody

has reported this problem before.

  1. Including the same files in two backup locations (not two

directories) is an error. Backing up the same file data twice would be a waste of bandwidth.

  1. There was a bug on Windows where file IDs were being

duplicated all the time, which was only spotted because I added this warning.

  1. Box Backup uses file IDs to track renaming of files. If you

use hard links then this will not work correctly and will cause your files to be renamed between the two directories all the time. This is the real bug.

Stefan Müller Wildi said:

I suggest introducing options to either suppress such warning messages altogether (maybe by type if that is possible?) or to reduce the number of warnings of identical type to 1 (like "showing only one of ##"). Something similar must already be implemented for I also read:

"c314-stefan bbackupd[1574]: WARNING: Suppressing duplicate notification about read-error"

This bug can cause data corruption in your backups! Do not ignore it! The warning is a warning for a reason!

Change History (4)

comment:1 Changed 9 years ago by chris

Cc: [email protected] added
Description: modified (diff)
Keywords: backup duplicate rename hardlink corruption added

comment:2 Changed 9 years ago by chris

Description: modified (diff)

comment:3 Changed 9 years ago by chris

Description: modified (diff)
Owner: changed from ben to chris
Status: newassigned

comment:4 Changed 4 years ago by chris

Implementing this properly requires the long-awaited (and not yet finished) snapshot support to be completed first.

In the mean time, we need a test that hardlinked files are backed up properly (but independently) without warnings and without causing rename tracking to do bad things.

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