Well, got the second drive synced and back on-line OK.
Just another issue with the disks I am using and something for those of you building a system...I have two
WD800JB 80GB EIDE drives. One came original in the PowerEdge 500SC server (3 years old), the other I got on eBay; it was manufactured in May of this year.
There was a significant firmware version difference in the two disks, and that was reflected in the write performance. I noticed that the newer drive was getting about
15MB better write performance than the old one (read performance was the same). I didn't take notice of this until after I had hot-added the second one yesterday. It looks like the firmware version (which cannot be updated

) makes a difference in the write performance.
The hdparm -tT results on the array itself line up with the slowest disk, which is what I would expect.The moral of my story here is that even when you get
"identical" disks, try to get them at about the same age (newer the better?) and/or have disks that can accept firmware version updates.
Don't get me wrong, I love even the performance that I'm getting, it is just something that those of you out there contemplating the same thing should be on the lookout for.
There may be a potential for a HUGE slow-down with certain drives.I may just try to get me another newer one and use it with the newer one, and use the older one to swap in and out periodically. This looks like one of the other methods some of you use to keep yet another backup.
Thanks for all the advice,
Kevin