Networker

[Networker] Use of WS_FTP client may increase tape consumption

2004-01-18 00:16:22
Subject: [Networker] Use of WS_FTP client may increase tape consumption
From: Ty Young <phillip_young AT I2 DOT COM>
To: NETWORKER AT LISTMAIL.TEMPLE DOT EDU
Date: Sun, 18 Jan 2004 00:06:26 -0500
All,

(Hopefully I searched the archives well enough before posting this !)

Don't know if this will be of use to anyone, but it made a big difference
for me once I discovered it on some of our Windows backup clients.  We use
NetWorker 7.1 at my site, but I imagine it's applicable to almost any
backup solution...

PROBLEM
Files on some Windows volumes are being backed up nightly even though they
aren't changing, irregardless of outside influence such as antivirus
software.

IMPACT
Wasted backup tape usage and unnecessary network bandwidth consumption.

SYMPTOMS
Symptomatic files appear to Windows as files without a "Last Modified"
entry.  Viewing the 'properties' of these files shows a modification time
somewhere between 1900 and 1903.

ROOT CAUSE
These files were at one time or another transferred (laptop --> server?
server --> server?   server --> laptop ?)  using an old version of
Ipswitch's WSFTP Pro with y2k issues, and that this FTP client incorrectly
reads modtime data of files on a given FTP server to which it's connected.

SUPPORTING DOCUMENTS
Ipswitch's knowledgebase has something about this:
http://support.ipswitch.com/kb/WS-19981203-CK12.htm

Curiously, the page says that this is "not a bug; this is the way the
software was designed" (?!)  and that this problem is a server-side issue
(again, ?!)

PROBLEM REPRODUCTION/TESTS
I have reproduced the problem in the following environment:
Windows XP
WS_FTP Pro 4.53
Solaris 8 FTP server
various win2k and 2k3 file servers

TEST RESULTS
Modtimes of files which the FTP server reports as 10/07/2003 are being
reported to the WSFTP client as 10/07/1903, and subsequently transferred
to my laptop and fileservers with that (incorrect) modtime.  The resulting
files are backed up daily because Windows cannot report files created
before 1/1/1980 (according to MS), thus tricking NetWorker into thinking
they need to be backed up again.

If we use a different FTP client (i.e. FileZilla or Reflection FTP) the
correct date is displayed and carried across the wire.

SUGGESTED RESOLUTION
A VBS script or other utility for reading and modifying (as necessary)
the 'last modified' date entry for files on Windows.

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