Messages

1

Skwire Empire / Re: Release: SFV Ninja (Simple File Verification application)

« on: September 11, 2012, 06:39 AM »

Hm, seems like a bad idea to run multiple instances at one time, at least for long-running jobs. You'll see much decreased throughput (way worse than linear degradation), and all the back-and-forth action is going to be stressful on your harddrive heads.

-f0dder (September 10, 2012, 07:51 AM)

If I run 3 instances against folders on 3 separate physical drives it's definitely quicker than running them one after another, and I can go to bed and forget about it

As for the wear on my drives - I figure that's why we have so many backups in the first place!

2

Skwire Empire / Re: Release: SFV Ninja (Simple File Verification application)

« on: September 10, 2012, 05:00 AM »

Were you aware that one SFV Ninja instance can load multiple checksum files into its list?

-skwire (September 09, 2012, 02:37 PM)

Yes, thanks

My archiving "strategy" requires separate checksum files for each top level folder though, so when creating the files in the first place it's easier to just run up a separate instance per folder

3

Skwire Empire / Re: Release: SFV Ninja (Simple File Verification application)

« on: September 09, 2012, 02:27 PM »

SFV Ninja is single-threaded so I'm not certain how much benefit you're getting from running multiple instances.

-skwire (September 09, 2012, 01:58 PM)

I guess the benefit (for me) is that I can fire up a bunch of instances in one go and set them to creating/verify checksums on a load of folders, then just leave them to get on with it - eg. overnight - rather than having to do each one sequentially.

Thanks again

Ciao
Stefano

4

Skwire Empire / Re: Release: SFV Ninja (Simple File Verification application)

« on: September 09, 2012, 10:38 AM »

Hmmm...I did some thinking about this and made a small change in the code.  Please redownload the zip and let me know if v1.1.3.2 makes any difference in your tests.  Thank you.

-skwire (September 07, 2012, 03:03 PM)

Hi skwire, thanks for the speedy update!

Just ran up 10 instances at the same time to test and no spurious "bad" results, so it looks good!

Thanks again

Ciao
Stefano

5

Skwire Empire / Re: Release: SFV Ninja (Simple File Verification application)

« on: September 07, 2012, 08:38 AM »

Hi, thanks for this program

Pretty sure I've found a bug with it when running multiple instances on Win7 64bit. To recreate:-

1. Create a checksum file (I used Md5) for a directory containing a few hundred files of around 20mb each (I'm checking .CR2 image files). Save it in the directory.

2. Open TWO instances of SFVNinja by double-clicking the .Md5 file.

3. Start verifying all files in both instances.

Both instances should report a random selection of "bad" checksums.

If you only run 1 instance of SFVNinja or leave one open but not verifying while you verify with the other, then all files are verified as ok. As soon as two instances are verifying at the same time, spurious "bad" results occur.

The same problem occurs if two or more instances are verifying different directories against different checksum files.

I'm guessing it's some kind of threading issue.

I haven't checked if it also happens if one instance is creating new checksums while a second is verifying a different directory, but I expect it does as that's what I was doing when I first started seeing "bad" checksums. The scenario above was created specifically to test for this bug.

This had me very worried that my files were randomly corrupting themselves in-situ for a while!!

Luckily, the workaround (to only run one instance at a time) seems to work, although of course it's less convenient.

I'm using Version 1.1.3 Build 1

Thanks again anyway!


Ciao
Stefano

www.stefanobrunesci.com