At one time, maybe a year ago, I was trying to find a way to copy big files around a small network without choking the network and / or the sending or receiving computers.
Well, I've finally found it. The utterly useful Robocopy utility from the Windows Resource kit has a
/IPG:n : Inter-Packet Gap (ms)
flag that will delay each subsequent packet.
IPG - will send a 64 KB packet followed by a delay of n Milliseconds. If my math is correct, a 1ms delay every 64KB would generate a maximum of 6 MBps - but it's actually much less on a 100Mbps LAN because it would take a significant portion of the time to transmit the packet.
- note the tricky 3rd parameter specifying the filter, this is different from the regular Windows / DOS copy or xcopy syntax.
robocopy "d:\Company Shared Folders\IT" \receiving2\c$\backups *.bkf /ipg:10 /zb
- for a single file from current folder (".") to w: drive using ipg to give other users a chance to access files: robocopy . w: really-big-file.img w: /ipg:4
ROBOCOPY source destination [file [file]...] [options]
Robocopy does not do authentication. To copy to network shares on different domains... something like this can work:
net use \\server1\g$ /user:domain1\user1 *
net use \\server2\g$ /user:domain2\user2 *
robocopy \\server1\G$\testdir\%3 \\server2\g$\uploads
2007-06-23: Another tool, supercopier, this one with a GUI. Haven't personally tested it yet: http://sourceforge.net/projects/supercopier/
I had a need to try this today. Only the GPL source code is on Sourceforge. Visit the homepage for binary install for Windows:
Update 2014: This seems to be infected by malware these days. :(
This program works great! There's a simple drop down to limit the transfer to 1, 2, 4 or custom MB/sec.
Copying all files that have been changed recently
Robocopy changed files - http://ss64.com/nt/robocopy.html
ROBOCOPY source_folder destination_folder [file(s)_to_copy] [options]
/E = empty -- don't use... seems to occur before MAXAGE, so, a LOT of folders get created
/S = subfolders
/L = list only
/Z = network restartable
ROBOCOPY "C:\TEMP" "C:\TEMPTEST" *.* /L /Z /S /MAXAGE:7
ROBOCOPY "D:\Company Shared Folders" "D:\ToMove" *.* /Z /S /MAXAGE:10
ROBOCOPY "D:\Users Shared Folders - Delete in 2013" "D:\ToMoveUsers" *.* /Z /S /MAXAGE:10
ignore errors while copying: robocopy c:\ d:\ /MIR /R:0 /W:0
The Reg List
A fellow tried to move 60 million files. Mentions "richcopy" and ultimately uses Linux as a middle man to handle really deep folder trees.
Unfortunately, it's time to avoid xcopy. Even though I used it for decades, xcopy on XP will bomb if the file path hits a 254 character limit, thereby baffling everyone. Try robocopy.
xcopy - continue if errors found (e.g. bum spots on disk): xcopy /C/H/R/S/Y c:\ d:\
Windows Vista added i/o priority. There are tools that will let you adjust programs to have low disk priority.
e.g. http://processhacker.sourceforge.net/ (not tested)
Tags: Win, w2k, winxp, xcopy, robo copy, slow, file, backup, mirror, speed, robocopy, supercopier,