Several people have sent me alternative answers to the tip "Upgrading a RAID 1 Configuration," November 15, 2001, InstantDoc ID 22730, in which I explain a particular process for upgrading two 9GB hard disks in a RAID 1 configuration to two 18GB hard disks without losing data. The following reader suggestion is the most thorough of those I've received. Although I haven't worked with the add-on the reader specifies, I can see the advantage of using it if you're a VERITAS Software shop; other backup add-ons probably work as well. Thanks to the reader for the information.

"A few years ago, I ran Windows NT Server 4.0 on a Dell PowerEdge 4300 dual-processor machine, which served as my company's Lotus Notes email server. I used RAID 5 with a hot spare, with the bootable partition on a RAID 5 array with six 9GB disks. I also used VERITAS Backup Exec on the server; the machine had its own DLT drive and performed an independent backup every night.

I wanted to upgrade to six 18GB disks. After contacting both Dell and VERITAS for advice, I installed the most recent BIOS upgrades the weekend before my migration. I also installed the Backup Exec Intelligent Disaster Recovery (IDR) Option add-on and created IDR 3.5" disks. This package ($495 list price) creates either disks or a bootable CD-ROM that you use to recreate a server after a disaster. My theory was that I could use IDR to rebuild my machine even though the disk configuration was different from when I made the disks.

On the Saturday of the cutover, I stopped the server's Lotus Domino service and completed a full backup to the local DLT tape. Then I shut down the server and removed the 9GB disks. I installed the 18GB disks, put in the first IDR disk, and powered the server back up. IDR prompted me for the remaining disks and the OS CD-ROM. The add-on then rebuilt the OS on the new disks and installed the drivers for the DLT tape drive. IDR then asked for the DLT tape. I put the tape in and went to lunch. I was restoring quite a lot of data, so this step took 2.75 hours. I then rebooted and tested the server: It ran perfectly. The total downtime for the operation (not counting the hour I spent on BIOS upgrades and installing IDR) was about 6 hours.

The server ran without a hitch for another 1.50 years, when the boot sector became corrupted. At that time, I went to my disaster-recovery kit (I keep a binder that contains the IDR disks and OS CD-ROM for each server) and used the first IDR disk which did the trick. The server was back up in less than 15 minutes. I've also had good luck recovering a Novell NetWare 4.11 server. I have no reason to believe this approach to a hard disk upgrade wouldn't work on Windows 2000. I've installed IDR on all my servers."