Backup of long file names not possible (> 260 bytes)

Pre-Release and beta version of AISBackup
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compumaster
Posts: 11
Joined: Fri Feb 03, 2006 9:04 am

Backup of long file names not possible (> 260 bytes)

Post by compumaster » Fri Oct 06, 2006 6:20 pm

I've got many files in our network with long path names (typically created with tools like NDoc and NAnt).

When AISBackup trys to backup those files, it can't do this task and provides an error message "File Deleted before backup".

One of the reported file names is:
\\srv10.lan.compumaster.de\dfs\Dev\thomas gruppe\Website\!Backups\2005-10-18\Archiv\CompuMaster\ADS Synchronization 2 CWM\Sources (Copy, Master @ CM)\ndoc\doc\CompuMaster.camm.WebManager.Services.AdsSynchronization.CustomImport.AssignAdditionalAccountSetting.html

Or let's better say, it is the following file on drive R:
R:\Dev\thomas gruppe\Website\!Backups\2005-10-18\Archiv\CompuMaster\ADS Synchronization 2 CWM\Sources (Copy, Master @ CM)\ndoc\doc\CompuMaster.camm.WebManager.Services.AdsSynchronization.CustomImport.AssignAdditionalAccountSetting.html

Expected is the following:
Application should be able to backup also path names with more than 248/260 characters.

Barry
Site Admin
Posts: 1507
Joined: Tue Aug 20, 2002 3:16 pm

Filenames > 260 Bytes

Post by Barry » Mon Oct 09, 2006 10:12 am

I see the problems, and your filenames are < 260 bytes when accessed using the drive letter and > 260 bytes when accessed using the share. AISBackup is using the share name rather than the mapped drive letter, nevertheless this should have worked if we pre-pended \\?\UNC\ to file filename, which we now do, and this will be uploaded as soon as the restore functions have been tested with the same files.

The \\?\ prefix will enable AISBackup to backup filenames of up to 32700 bytes, however, although path names of > 260 bytes are supported by NTFS they are not by any current version of Windows.

Barry

Barry
Site Admin
Posts: 1507
Joined: Tue Aug 20, 2002 3:16 pm

Filenames > 260 bytes

Post by Barry » Tue Oct 10, 2006 4:08 pm

Build 294 of AISBackup has been uploaded, this fixes the problem backing up files where the path name is > 260 bytes.

www.aiscl.co.uk/downloadaisbackup.htm

Barry

compumaster
Posts: 11
Joined: Fri Feb 03, 2006 9:04 am

long path names

Post by compumaster » Wed Oct 18, 2006 8:17 am

looks as it would work, now :D
thanks!

compumaster
Posts: 11
Joined: Fri Feb 03, 2006 9:04 am

long path names

Post by compumaster » Wed Oct 18, 2006 8:18 am

looks as it would work, now :D
thanks!

Barry
Site Admin
Posts: 1507
Joined: Tue Aug 20, 2002 3:16 pm

Restoring long file names

Post by Barry » Wed Oct 18, 2006 10:31 am

Your file names were border line 'too big', i.e. they were <= 260 bytes when accessed with a drive letter and > 260 bytes when accessed using a share name.

There could be a down side to this fix:

AISBackup now allows files to be restored to a new folder where the total path name would exceed 260 bytes and therefore be in violation of Windows maximum path length. AISBackup will asks a question before it restores files with a total name length of >260 bytes - so you do not have to answer 'yes'. If anybody wonders why: Windows supports total path names <= 260 bytes, NTFS (the disk Windows uses) supports Unicode path names up to 32767 bytes.

If anybody ever gets stuck with an inaccessible file in this way (You cannot open the file in Windows Explorer for example) simply rename the owning folders to a smaller name until the total path name no longer exceeds 260 bytes or use the 8.3 short names instead.

Barry

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