Offline Files Truncated at 2GB?

[KMyers1]

Am using Offline Files in Windows XP SP3 with all critical updates.
Was attempting to append data to some very large files that happened
to be on a mapped network drive using Offline Files. While the append
was in progress, I could see the file size in Explorer slowly increase
to the final size of over 3GB. Within a few seconds after the append
operation was complete, the file size would suddenly be changed to 0
(zero). Opening the file confirmed that it had been truncated to zero
bytes. I tried this several times using different techniques for
appending to the file (include a utility that I wrote myself). In
every case, the file size was truncated to zero immediately after the
append operation completed. The problem appears to occur any time
that appending to a file would result in a file size exceeding 2GB.

When I tried the same thing on a local drive, not using Offline Files,
this file truncation did not occur.

Does anyone know:
1. Is this problem specific to offline files, or does it affect all
files on mapped drives?
2. If this problem is specific to offline files, does it only occur
when working offline, or does it also occur when connected to the
offline files server?
3. Is there any way to correct or avoid this problem other than not
using offline files or mapped drives?

Thanks,
Kevin M.

 

[Andrew McLaren]

Hi Kevin,

Not sure of the complete answer, but ... on XP, the Client-Side Cache is
limited to 2GB by default. I don't have a specific reference on hand,
but have definitely encountered this before. This limit was increased
(or removed) in Vista. The concept of "offline files" is to keep a local
CACHE of files (rather than master-copies of the files themselves); and
like all caches, it is somewhat restricted as to size (the principle of
locality).

You may be able to work around the issue by increasing the disk space
available for the CSC cache (under Tools, Folder Options, Offline
files). But I'm not sure if this will bypass XP's 2Gb limit. If it's a
big problem for you, then plan to move to Windows 7 where the CSC limits
are all increased.

Hope this helps,

Andrew