USB (external) drives are becoming very popular these days for backups, extra storage, data transfer etc.
I have used them myself with good results, and use a variant - a USB flash drive - almost daily to keep my home computer
in sync. with my office PC.
The main problem one runs into with these drives is the USB cable itself - it is prone to loose connections.
Pushing in the cable more tightly, or even replacing it, will often fix the problem.
Today I ran into a problem that was a bit different.
The problem
A user purchased a new 120 GB Seagate IDE/ATA hard drive (model Barracuda 7200.9 ST3120814A).
The goal is to replace their failing system (C:) drive with this new one.
As there is too much legacy software installed on the old drive, it was decided to make an exact clone of the old drive onto to the
new one and simply swap in the new one to replace the old.
The old drive was not spinning up reliably each time, e.g. you might need to turn the power off and on about five times before it
spun up, but once it was spinning it works fine so long as the power is applied.
For this reason we decided to not risk shutting the machine down, but instead to install the new drive into a USB enclosure, then install
Norton Ghost on the old drive and make a clone onto the new, now external USB, drive.
We purchased a new USB drive enclosure (Acomdata model 509) to hold the new drive
(http://www.acomdata.com/hdp/harddrives-509_Enclosures.html).
It is attarctive looking, and comes complete with a power adapter and a USB cable.
Opened the enclosure, mounted the new drive (after setting the jumper to the "Master" position), reassembled, and decided to
test it on another machine first.
It beeped, and a familiar looking message in the system tray said "New Hardware Found - USB Mass Storage Device" etc.
Things were looking good for a few seconds, but then "There was a hardware problem installing your device etc..."
Oops! A search of "My Computer", "Disk Management" etc. showed no trace of the new drive.
Tightening connections, power off/on, reboot etc. yielded nothing, so read the small booklet that came with the Acomdata enclosure.
It referenced a "PDF manual" that is on the accompanying driver CD, but there no pdf there.
Luckiliy the pdf manual was found on their web site, but it seemed to cover every scenario other than this one.
Connecting the USB drive to two other computers also led to the same failed outcome.
All computers are running Windows XP SP2, so should not be a driver issue.
I decided that possibly the drive needed to be formatted first, and there was a small chance that it was even a defective drive, so
removed the drive from the enclosure and mounted it as the internal slave drive in another system, where it was partitioned and formatted
successfully with no problems.
The drive seemed normal in every way when mounted internally.
Installed the drive back in the external enclosure (after setting the jumper to "Master"), plugged it back in into the USB port, but
unfortunately it still gave the same error that "there was a hardware problem...".
Checking Device Manager showed the new drive listed in the USB Controllers section at the bottom as a "USB Mass Storage Device" but
with a yellow icon to indicate a problem.
Uninstalling and rescanning for devices led to a repeat of the same error.
Checking for updated drivers on the web yielded nothing useful.
The solution(?)
Next, thinking that perhaps there was some incompatibility between Seagate drives and this particular enclosure, I replaced the Seagate
drive with an older spare Western Digital drive (80 GB, model WD800 Caviar) and plugged it in.
Suddenly things were working better.
The drive was recognized within seconds and showed up in Windows Explorer like any other drive.
On a hunch I removed the WD drive and inserted the Seagate drive in the enclosure again, plugged it into the USB port, and turned the power on.
Somewhat unexpectedly, the drive that was formerly not working, was now working also!
It showed up everywhere, Disk Management, Windows Explorer, Device Manager etc.
It works everytime since then even when disconnected and reconnected several times.
Not able to explain this, I guessed that the Western Digital drive had been identified more correctly by the enclosure firmware/Windows causing
the correct driver for USB hard drives to be loaded, and later when replaced by the Seagate drive the new driver came into play and
worked correctly with the Seagate as well.
Oddly, when the external drive (with Seagate) was plugged into the other systems where it was failing before, it worked there as well, so
it seems more likely an issue with the enclosure firmware from Acomdata.
Possibly the firmware was identifying it as USB flash memory before, and as a hard disk drive now?
Unexplained
In addition to the above, I have noticed some other quirks since then which I've been unable to explain yet.
After removing the (now working) external USB Seagate drive, I plugged in my USB flash drive, and deleted a file from it.
It worked, but suddenly a new folder named "Recycled" appeared in the list of folders (see figure below).
This folder had never been there in the year or so I have been using that USB memory stick.
Moreover, the folder actually held the file I had just deleted, and the file was not truly deleted until I cleared the Recycle bin.
Formerly, deleting a file from the USB memory would always delete it permanently right away.
The "Recycled" folder circled in red was never there before.
It seems as if the system is now treating the USB flash memory stick as a normal hard drive, while earlier it was treating it more like
external/network memory.
The other quirk I've noticed is that when the external (Seagate) drive is plugged into one of the systems, and the system is rebooted,
the drive will sometimes appear in the list of drives, and sometimes not.
In the cases where it does not appear, turning the external drive power switch off and back on makes it appear every time.
These are some of the unexplained USB quirks from today. I suspect a lot has to do with bugs (or features) of the Acomdata USB enclosure firmware,
but as I learn more I'll update this page.
