Factory Fusion drive. 3rd party (OWC) RAM. never dug around terminal to tweak the OS, but i did use it once (about 4 clean installs ago) to delete iTunes..have since reformatted and cleanly installed mavericks about 4 times since then without going back into terminal for anything else.
If all file transfers are failing, then it definitely sounds like a RAM issue. I would try and run a RAM test. memtest86 I think works for Macs.
http://www.insanelymac.com/forum/topic/285041-how-to-run-memtest-under-mac-os-x/
http://osxdaily.com/2011/05/03/memtest-mac-ram-test/
https://www.google.com/search?q=memtest+mac
thanks. on test sequence 2 of 4, the first one came back without any errors, but will let it run through.
also did a hardware diagnostic test via the built in utility on osx, that tested memory as well and showed no errors. I'll report back.
I would let it run as long as you possibly can. I have sometimes let tests run overnight for machines that are truly suspect (I work in IT for a living). Sometimes it will be just one bit or byte that is failing and it can take a couple passes to see it. If this shows nothing, then when you take it on Tuesday make it clear that you have done all these things and that there is some deeper issue that they need to look at.
Gotcha. 4 passes showed nothing (all tests passed), but I'll let it run overnight.
What happened when you went to the Genius appointment? Do you have applecare?
so after all that, I could not replicate the problem at the genius bar. after weeks of torment, torture, and iTunes hell, the problem seemed to rest with not unplugging my mac for long enough. it seems the hour or so the mac mini was unplugged and in transit was long enough to possibly reset the SMC settings. I'd unplugged before, but perhaps not quite long enough.
needless to say i felt like an idiot as my iTunes would successfully add file after file to my library without fail. never did i want it to not work so bad, only to have it go through each time.
***MAJOR EDIT*** and now I see why things worked so smoothly. with the SMC reset, somehow my tunes media folder was also reset to the internal hard drive and off of the external. resetting the library to the correct location (my external drive) and trying to copy files to it has re-introduced the problem. major major face palm right now. I have verified this external drive already, and it shows no errors or trouble. it works fine when connected to my mac laptop so i'm sure the drive is not the issue btw.
needless to say, i'll be heading back to the genius bar tomorrow.
I think that is the best bet. The fact that an SMC reset partially fixed the problem to me indicates a hardware and one that the Genius bar should be able to figure out.
I am so sorry you are having these frustrations.
Good luck and report back!
so the final verdict here - genius bar had no solutions, only that suggesting by keeping my iTunes library living on my mac mini hard drive separate from my media folder which lived on an external drive, that i was essentially outsmarting iTunes, and that i would continue to see issues. apparently i fall into the 1% of iTunes users that want to manually configure the settings to be just right for me, and there are no solutions for me.
what i finally resolved to doing was to buying an external 1TB drive which now houses both my completely rebuilt (new from scratch so i lost play counts, etc..) iTunes library and my media folder. I've not had any issues with importing the ripped movies with this setup. I'll hope it continues. Hopefully apple will bundle the iTunes library in the future the same way they've done with aperture and iPhoto, and allow me to once again reference my files externally should i choose to.
I glad you got a "solution" and that things seem stable. I am sorry you went through such extreme heart/headache to do what you needed.