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jhodgesivFlag for United States of America

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Uninstalling and reinstalling external hard drive causes network connection loss

Hi all,

This question is a follow-up to one I previously posted, in which my SBS 2003 R2 machine would lose internet connectivity seemingly at random.  I've since determined that it's not (completely) at random, but happens (sometimes) when I remove and install a device.

Here's the situation.  I've got an on-board Broadcom NetXtreme dual-port GbE adapter, which is the external-facing adapter for the server.  Also on this machine is a Rosewill RC-216 eSATA RAID adapter, which is connected to an external 2-bay hot-swap enclosure.  I've got several sets of hot-swap disks, configured in JBOD, which I use as backup media.  Each morning, after the nightly backup is complete, I swap out the pair that's in the enclosure with another pair.  The arrays are named BACKUP A, BACKUP B, etc.

The backup drives don't show up as removable devices on the system (instead, the array shows up as "BACKUP A SCSI Disk Device," which is strange because they're not SCSI).  In order to safely remove them, I created a simple batch file:

@ECHO OFF
DEVCON REMOVE *BACKUP*
ECHO Press any key when the drives have been switched ...
PAUSE
DEVCON RESCAN

which uninstalls (exactly as would happen if you uninstalled from Device Manager) any device whose description contains "BACKUP", and then scans for new devices after a keystroke.  This seems to work fine.  Often when this script runs, however, the machine loses internet connectivity.  No errors pop up, and the Broadcom still shows as installed and connected, but I can't ping external IPs.  If I go into the Broadcom control suite and run a Cable Analysis test (which seems to force a restart of the NIC), connectivity is restored.

I've noticed that both the Broadcom adapter and the Rosewill adapter share IRQ 16, but I didn't think this was an issue in modern incarnations of Windows.

Any suggestions?
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plug1
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What happens if you simply remove the disk and re add the new ones without running your re-scan. Do you think the rescan is discovering your network adaptors incorrectly?
After all if they are hot swap drives then the rescan isnt needed is it?
Avatar of jhodgesiv

ASKER

It's a hot-swap enclosure, but the drives aren't showing up as AHCI hot-swap drives.  I'm wary of removing them without letting the OS know about it, because I want to make sure that they aren't being written to when I remove them (to avoid data corruption).

The network adapter is never removed, and it doesn't show as discovered in the rescan.  If I just do the rescan without removing the drives, the problem doesn't happen.  I'm thinking the issue has to do with the OS allocating resources to the "new" drive that are used by the Broadcom NIC, but I'm not sure where to look to try to dig deeper into this.
I'd take the plunge and remove and re-add without the rescan, it should be tottaly external to the OS and handled by the backplane itself.
After looking around a bit more on this issue, it appears the command I should have been using was "devcon disable" rather than "devcon remove"; I found a nice GUI utility that does just this at http://mysite.verizon.net/kaakoon/hotswap/index_enu.htm.  I'll see after a few days whether the problem recurs (though I'm still baffled as to why what I did would create those symptoms).
Have you tried it without the script yet, I think its totally unneccesary
ASKER CERTIFIED SOLUTION
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jhodgesiv
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