Problems with ShadowProtect backups

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RickH
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Joined: Thu Dec 13, 2012 8:00 pm

Problems with ShadowProtect backups

Post by RickH »

ASUS P7P55D-E Pro board (P55 Express chipset), i7-875K CPU, Win 7 Pro 64-bit SP 1 fully patched, C: and D: are separate SSDs, F: is an HDD used for backups. Using FancyCache Disk 0.8.0, C: and D: set for 1GB cache with 4KB blocks, LFU-R, Read/Write, Deferred Writes @ 300 secs, release after write, no L2 or other options selected. F: set for 256MB cache, 4KB blocks, LFU-R, Read/Write, Deferred Writes @ 10 secs, overcome HDD C1 issue, no L2 or other options selected.

I use StorageCraft ShadowProtect for backups, currently v. 4.2.7.19756, scheduled to do automatic incrementals every 12 hours. I've encountered blue-screen crashes now 3 times when it tried to back up my boot C: system drive, but it has no problem backing up my identical model D: apps/data drive. The bugcheck info:
1) 0x7F (0x8, 0x80050031, 0x6F8, 0xFFFFF800036D7B88)
2) 0x7F (0x8, 0x80050031, 0x6F8, 0xFFFFF800036A6B88)
3) 0x7F (0x8, 0x80050031, 0x6F8, 0xFFFFF8000361EEB5)
which Microsoft says is an UNEXPECTED_KERNEL_MODE_TRAP, Double Fault, probable kernel stack overflow.

ShadowProtect first backs up D:, which always works without issues, and then moves on to C:. If caching is enabled on C: it then usually (but not every time, I think it's worked once or twice out of several attempts) crashes with the above fault very quickly. If I disable caching on C: there's no problem. Since C: and D: are identical model SSDs with identical cache settings, the only real difference is that C: is the bootable system drive. The OS's paging file is also on C:, and there is no hibernation file (disabled).

Let me know if you need more info , or want me to try some different settings or a different build or something. I can do a bit of testing for this, though not a huge amount (no serious damage done, but it takes quite a while to restore things if the drives get corrupted).
RickH
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Joined: Thu Dec 13, 2012 8:00 pm

Re: Problems with ShadowProtect backups

Post by RickH »

It turns out ShadowProtect has a nice feature where you can set it up to execute an app or batch file before and/or after the backup session. So for fun this weekend (yeah, I'm weird, I know) I kludged together a workaround for my bug using AutoHotKey to automatically disable the cache on C: before the backup and restart it afterwards, and it's working great. It's not like the cache really does much good during backups anyway, it just gets flooded out.

So this immediately suggests another feature; it'd be much easier for normal sane people to do something like this if FancyCache provided a simple command line utility for starting and stopping specified caches on demand. It'd need to run without admin mode though, I'm pretty sure the backup service daemon can't or won't launch apps that require "run as administrator" elevation.

Just another one to add to your pile. Keep on truckin'.
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Re: Problems with ShadowProtect backups

Post by Support »

Hi RickH,

Thank you very much for your testings and feedback!

We'll check this issue. And we will also provide command user interface in the future.
Manny
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Joined: Tue Nov 13, 2012 11:42 pm

Re: Problems with ShadowProtect backups

Post by Manny »

+1 to CLI request
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