# Troubleshooting - IRQL7

Some users have reported either
Snapshot error: Strange error while reading data
or
Snapshot error: Driver reported error: <1634: IRQL5>

The reason is, that some unusual driver modifies the kernel internals in a way, that disk access is used with Paging (virtual memory management) disabled.
This is unusual and probably due to some lazy driver programmer (whoever it is).

So far Drive Snapshot's 'politic' has been to avoid to run in an unknown environment (to avoid bluescreens as much as possible); therefore the backup is aborted as soon as above condition is detected.

Starting from 1.32 (4 dec 2003), Snapshot has been modified to allow to continue in this condition.

> Warning: Snapshot has been manually verified, it *should* work with paging disabled.
> However, it hasn't been tested on many systems with these conditions, as these conditions are rare, and not reproducible by us.
> There is a certain possibility, that running Snapshot Backup will now no longer stop the backup, but instead BLUESCREEN your PC.
> When running Snapshot now (specially the first time), please make sure, you can tolerate the (low) probability of a BLUESCREEN, and don't run it under productivity conditions.
> Running Snapshot without the fix however is as safe as it was before.

> Should you get a BLUESCREEN please go to Reporting a Bluescreen section below to help us fix this issue.

However, don't be too afraid: even if Snapshot causes a bluescreen, no data corruption will happen.
When the computer reboots, you'll see a CHKDSK running; after that the system will continue to run as usual.

## here's the fix.

Start Snapshot from the command line, and add the parameter '-!IRQL7'
i.e.
start either
c:> C:\programs\Snapshot\snapshot -!IRQL7
for the GUI or
c:> C:\programs\Snapshot\snapshot -!IRQL7 C: X:\c-drive.sna
This option is considered a temporary fix.
This option will vanish again as soon as we think that it works proper; therefore we didn't invent a GUI for it,...

If that fixes the problem, we want feedback.

## Reporting a Bluescreen

If that does not fix the problem, we want feedback, too.

It would be nice, if you could set your system settings to 'Kernel Memory Dump'

> My Computer ->Properties ->Advanced ->Startup and Recovery->
> Write Debugging Information = Kernel Memory Dump

This will dump all kernel memory (~50MB) into the file %SystemRoot%\MEMORY.DMP,

If you get a Bluescreen, we apologize.
Usually, Drive Snapshot tries everything to avoid Bluescreens.
Unfortunately, the 'driver reported error:IRQL5' bug couldn't be reproduced by us (on many test maschines), so this is a bit running in unknown environment.

Please ZIP MEMORY.DMP and send it to support@drivesnapshot.de; we will analyse it, and try to fix the problem as soon as possible.

Thanks for understanding.

Copyright © 2001-2016 Tom Ehlert Software