Occassional I/O errors

[joelshort]

I am getting occassional I/O errors and I'm not sure if this is an issue with the core application or the scripts it shows up in.  Attached is the error I get when running the NBRGBCombination script.  I get a similar error using the SHO-AIP script.

[joelshort]

And here's another error that PI itself told me to record and pass on to the developers.  The attached error was preceded by another error stating that PI had recovered from a serious error and that I should close and restart a new instance of PI.

[Juan Conejero]

The error message says it all: insufficient disk space to write a swap file. Please note that approaching a disk full condition is dangerous and should always be avoided on all platforms. This situation is probably behind the sporadic I/O errors that you are experiencing.

The attached error was preceded by another error stating that PI had recovered from a serious error and that I should close and restart a new instance of PI.

This is a self-diagnostics procedure:

PixInsight has detected a problem related to internal processing history structures. This is a serious error that could cause subsequent corruption of critical data in memory.
Next to this message you'll receive a second error notification with more specific information; please record it and inform us about this problem on our support forums.
Although PixInsight has recovered full control now, to stay safe we recommend you save your data, terminate execution of PixInsight, and start again. Sorry for the inconvenience.

As the message says, PixInsight has recovered full control at this point. However, failure to write a swap file is inherently dangerous, and hence the recommendation to save your data (if possible) and exit the application.

There is no bug here, just the PixInsight core application doing its job as best as possible under degraded working conditions.

[joelshort]

Thank you for the reply Juan, however I'm still not sure what exactly the problem is or what to do about it.  This is on a relatively powerful computer (Win7, intel i7, 16GB RAM, 120GB SSD + 500GB HDD, Nvidia graphics).  There is currently about 20GB left on the SSD and 200GB on the HDD.  I am working on a large project in PI, a 4 panel mosaic with 5 workspaces open. 

[Juan Conejero]

Are you sure it isn't 200 MB, instead of 200 GB?

[joelshort]

Yes, there is currently 19.1 GB left on the primary SSD.  And 173 GB left on the secondary HDD.

But actually when the errors occurred there was about 12GB left on the SSD.

[NGC7789]

You don't mention how your swap is configured. Is it on the HDD? SDD? Both?

You mention your large project but you don't really say how large. While it's not directly related to swap size how large is the project file?

I could see a scenario where 20gb on the SDD is not enough. If I'm not mistaken 60GB of swap is the recommendation and if your project is sufficiently large you may need more. Perhaps investing in a larger or second SSD for swap is in order.

[joelshort]

I don't really understand what the whole swap thing means...

The project data folder is over 9GB in size.  The project is stored on the secondary HDD, while PI is installed and run from the SSD. 

[NGC7789]

You can read about swap settings here:

http://pixinsight.com/forum/index.php?topic=7644.0

If you have never changed your settings then by default the swap will be on your install drive and I would say the free space you have is not enough.