I would use robocopy. It will copy all the files with their exact permissions. It can be started in restartable mode, and can retry and wait for files that are in use. It will make a log that will tell you the status of the files you copied. You can use it to mirror a drive, do incremental backups to storage, exclude certain files and directories or backup based upon the archive bit. Lee Duynslager Information Technologist Integrated Plant Systems Michigan State University (517) 432-5296 -----Original Message----- From: MSU Network Administrators Group [mailto:[log in to unmask]] On Behalf Of Cameron Ramo Williams Sent: Tuesday, December 16, 2003 2:41 PM To: [log in to unmask] Subject: Question about copying large amounts of data Hi NAG members I'm the sysadmin for the Center for Global Change and Earth Observations here on campus. Our Center currently houses approximately 5 Terabytes of imagery data on two Dell PowerVault NAS systems. Recently I have been asked to copy all of this data over to a second NAS array temporarily because our current array (including the drives in the vaults) needs servicing. I can't pull the drives during the servicing and I have only about a 2 week time window to get the entire dataset copied and verified on the "mirror" system. What I want to do is basically copy the entire dataset, maintaining current ownerships/permissions, and verify the copied files are the same as the originals. The files are stored on an NTFS file system and the NAS is running Windows 2000 Advanced Server. Obviously with this amount of data I can't stream it all off to tape and reload it given the speed of streaming to tape and the sheer number of tapes I would have to have on hand to store close to 5 TB. I was wondering if anyone here on campus has done similar copying/verification on a comparable sized datawarehouse, or at least has an idea of what the best way to proceed in copying it all over to the second NAS with ownership and permissions intact. If you have any suggestions, let me know. Also, just for my own knowledge here on campus, are there many other departments here that have datasets of a comparable size? The Library perhaps, or the Cyclotron lab? Thanks for any ideas you can suggest! Cameron --- _______________________________________ Cameron R. Williams Information Technologist Center for Global Change and Earth Observations Michigan State University 101 Manly Miles East Lansing, MI 48825 (517) 432-4675 [log in to unmask]