I have stayed by the way side on the discussion and have a few comments. So here is my 2 cents.
Andy and I have become very good friends over the years, even though we have never personally met each other in person. What we have agreed on is that at times we will disagree. We accept that and move on.
Early years (70's) we were required to scan the surface to create a list of bad sectors. This practices is NO LONGER DONE. All rely on the SMART technology to correct this on the fly. After having Numerous issues with the OLDER Snap's multi-disk arrays (raid5) , I have started using a utility to do a full scan and build this table, prior to use. Building this table prior to use has pretty much killed a lot of timing problems. So I can safely say that the older units (2000, 2200, 4000, 4100) preform better and have fewer problems with timing.
I think the SMART tech is a very good system for single drive system and for newer hardware that support it. Unfortunately the SnapOS and related HW does not seem to support it. The Snaps seam to work with 1 SMART replacement of a bad sector. It's when multiple bad sectors are hit consecutively that throws the timing off, which in turn the snap may mark the drive as bad. Since the SnapOS is built on a heavily modified XFS on BSD (v1.1?) it is not very forgiving when you have a drive problem. The hardware controller on some snaps have a problems with EIDE drives, ultra 133. These are easier to identify due to a 40 cond IDE cable. Those with 80 cond do not seem to have the problems.
The Guardian OS is built on Red Hat Enterprise Linux and fully supports the SMART tech. Even though I ran in to issues with some 400gig Seagates that worked, without reporting errors, the performance stunk. Running my drive utility to build the table, revealed that 1 drive used up 3/4 of the reserve sectors. (I think with that many errors depending on location may eventualy come loose and crash the heads.) And another that has a very HIGH Seek error. With all of the bad sectors mapped out the drives, it now works at a higher level of performance. I can tell when the one drive is having it's seek problem in performance. I have moved this set of drives to a server that is used for archiving, and does not run 24/7. When it comes to seek problems, this is where Raid Edition Drives with a min seek time shine. As you know these drives are considerably heaver than a std drive due to more powerful servos and motors. Also if your test for performance the RE drives will out perform a std (non RE) drive when used in multiple disk arrays. There seams to be 1 drive out of the set that will have seek problems, my good luck. Now if you hand pick these drives, or have the machine to tune the drives so all match, any will work. And may have the same performance as RE drives.
Knowledge based on school of hard knocks, experience.
And as you should know by now, the Snap 4100 has a problem with larger drives and the mfg had to modify the MB's. The bad thing about this is that they only repaired the models that were shipped as large capacity. So if a user upgrade drives the problems showed up again. Snap position is that we only support what was factory shipped. The problem was related to noise on the servos impacting timing. This pretty much killed any reliability/stability in the array. So I can safely say Timing is a MAJOR PROBLEM when it comes to multi disk arrays on hardware that does not support the SMART technology.
I do think the adapters have merit, being on all drives the delay should be across the board. But why use them when you can purchase the same drive with the correct interface (IDE) at a lower price than the SATA drives + adaptes. If you are relying on a system for operation, why take the risk. Now if you are buying 1000's of SATA drives for a big corporation, I would think it's time to replace the older IDE hardware. Or make a large purchase of IDE drives to support your older system.
I would estimate that 98% of all users here on this site are home users. Some use the same equipment at home as they had at work. Mainly due to the fact the equipment was updated and the company sold the old hardware. Some are more prone to trying things out of the normal to get things working. In most all cases, this site is where users come looking for help on Snaps NAS's. More so, since Adaptec bought SnapAppliance and killed ALL FREE SUPPORT. With that said, the regulars here are more prone to support hardware as shipped. If it works for you that's great. If it fails you compounded the problem with the extra hardware.
My 2 cents are now gone so I will stop ranting.
