I’ve got a new computer that seems to work perfectly -except- when I use Unity 3.x on it. It’s a Toshiba Qosmio notebook running Window 7 Home Premium with a 22" external monitor connected to and is my main development machine. If I use any of the other applications (Photoshop, Gimp, Blender, Unity 2.6.1, etc.) it works perfectly. If I run Unity 3.x (I’ve tried both 3.0 and 3.1) and then later reboot, the system does a “chkdisk” test of the hard drive because it sensed HD faults. I’ve tested this numerous times, rebooting frequently after running all the various applications I use, and it only happens after using Unity 3.x. I’ve reported this in a bug report to Unity Tech, but they can’t reproduce the problem and I’m afraid to continue to use Unity 3.x for fear that it might cause me to loose valuable data on my HD. Anyone else run into this sort of problem?
I may have found what was going on and (fingers crossed) fixed it. Apparently when I had an editor crash while running Unity 3.x it created some faulty files on my hard drive. When I rebooted Windows it saw that the hard drive was dirty and automatically did a checkdisk, but it didn’t fix / repair it automatically. For some unknown reason the auto-checkdisk only happened after I ran Unity 3.x, thus my reason for concern. A few days ago I did a complete chkdsk including repairs and I haven’t had this issue since. I’m running fsutil dirty query c: after every Unity 3.x session just to make sure. Hopefully that’s the end of that issue.
Yeah I would be skeptical that Unity3.x would be the direct cause as something this bad would have been reported by others long before now.
that and its not possible for it to do it at all as it has no access to the harddrive directly, only to the file system as provided by Windows / OSX
I’ve not run into this before (with any other application, including Unity 2.6.1) nor since (fingers crossed) but I’m almost 100% certain the initial issue was caused by the Unity 3.x editor crashing. In fact that editor crash locked my system and had to be powered down to reboot. I haven’t used Unity 3.x much since that crash, but now that it looks like I’ve identified the cause for the repeated chkdsk errors I plan on using it more.
Well it happened again. I was using Unity 3.1 then stopped for lunch. When I got back from lunch and powered up the computer it did a chkdsk (which I stopped to verify that the HD was dirty). The only app I used was Unity 3.1 and it popped up some script errors which I fixed before shutting down. Weird issue, but it only happens when I use Unity 3.1. 
I would say that I’m rather confident that you have guards running in the background for virus and malware purpose …
those unlike unity really have the low level access to cause trouble
but that being said, the issue you describe does not sound like caused by anything unles it crashed. if it comes up with checkdisk on a normal power down, then you have scheduled chkdsk. some defraggers do this along boot defragmentations for example.
also it can be setup for the system in general, I used to have it on the system partition before I had Diskeeper Boottime defrag on for each boot with it calling chkdsk, as I don’t think that its a bad thing and it also only takes less than a minute normally to check the 120gb or so of my C partition
It’s not a “scheduled” chkdsk, it’s happening because the hard drive is “dirty”. I ran “fsutil.exe” to confirm this. Could be the virus protection, but I’ve tried two different scanning utilities ( I recently dumped AVG for Microsoft Security Essentials) and the same thing happens. I also suspected it might be the hard drive, but it only happens when I run Unity 3.1, I don’t get any other drive errors, and repeated hard drive testing hasn’t revealed anything.
The problem is that a software can’t cause a dirty drive, only a failing drives and power problems due to the PSU can cause this.
But it might be that unity helps it showing up as it writes files on a pretty constant rate (comparable only to torrent downloads likely), so if there are errorous sectors it will show much faster thanks to unity.
I would recommend to fire up a tool that gives you detailed information on the HDD health by readong out the HD S.M.A.R.T. data
Perhaps try defragmenting and or uninstalling/reinstalling Unity. It may have installed onto a failing sector of the harddrive. Yes, you said it’s new, but crazier things have happened. Also, if you are in the market for a new personal security anti-virus/firewall I recommend Comodo Internet Security. 100% free for personal use, as I chose it over AVG so I only had one program running for firewall and anti-virus(as I had AVG/Zone Alarm running previously). Unity 3 should not be the cause of your problems though. It’s most likely a problem with the OS or another program. Did you try the recovery disk for Windows to check to make sure the OS is ok? Unity asks Windows to interface with the harddrive so perhaps there is a corrupted sector of Windows files causing it to write improperly?
Well I’ve tried all of the above suggestions: I ran chkdsk with the fix option. I ran several hard drive test applications for several hours and no errors were reported. I uninstalled Unity 3.1, defragged the hard drive (it was only 2% fragmented) and then re-installed Unity 3.1. I set up the virus scanner to ignore both the Unity application and project folders. I ran Unity 3.1 momentarily and so far no issues. Now comes the hard part, I have to wait and see what happens.
Thanks everyone for the suggestions, I’ll post back with an update in a few days…
The problem appears to be an issue between Microsoft Security Essentials and the Unity editor. If MSE’s “real-time” virus scanner is turned on, the problems occur. If it is turned off, the problems go away. I’ve filed support tickets with both Microsoft and Unity.
Have you had any luck solving this? I have the same problem but with F Secure Internet security. If I run this it will make my C drive dirty. I run CHKDSK and it fixes the problem and I log into XP. Then F Secure causes the same problem again. Spybot also can trigger it. Any insights will be greatly appreciated.
Thanks
The only “fix” I’ve found was to use a different virus scanner. I’m now using Panda Cloud and so far the only issue is that sometimes (perhaps 1 time in 10) I get an error that Unity couldn’t be launched, but other than that, my HD issues have disappeared. I’m on Windows 7 64bit so your mileage may vary…
Hello bigkahuna,
I have a Toshiba Quosmio x500 with win7 64bit home premium.
On my pc U3 don’t create any disk problem …at least until now 
I have also added a new SSD as primary disk and also with this no any problem.
…just for your info…
@kenshin - Congradulations on getting a great notebook! 
What virus protection software are you using, that’s what was causing my HD problems? I’m now using Panda Cloud and it’s working pretty well so far.
So I did another chkdsk /f, c: was clean, installed Panda and everything was fine until I did a full scan. Then Panda encountered a problem and now C: is dirty again. Have you tried doing a full scan and then doing a fsutil to check your c drive? Its odd that only 2 people seem to have this problem and there appears to be no solution. I’ve also checked the HDD with 3 different programs and it seems to be O.K.
I think it’s more than just us two, there have been other threads with people who have had other issues (crashing, etc.) all related to their virus scanner, at least that has seemed to be the common denominator. Yes, I checked my HD thoroughly and spent hours with Toshiba and Microsoft tech support. Nobody I spoke with thought it would be the virus scanner and they all verified that my hardware is working fine. In the end they all blamed the software (which, in my experience, is the default reply they give when they really don’t know what the problem is).
I’m afraid I’m not entirely surprised that Panda isn’t working for you. The only consistency I’ve found with this problem is that it is absolutely inconsistent. 
That’s why I ended up trying 3 scanners before finding one that seems to work 99% of the time. My only suggestion is to keep on trying different virus scanners until you find one that works and back up your HD frequently. Fortunately there are several to choose from. What didn’t work for me might work for you. I now have an external HD constantly backing up my system (using Acronis, which also has its issues… argh).
I’m thinking of doing a fresh XP install after reformatting the C drive as a last resort. Did you try that by any chance?
My machine was virtually brand new when I first started having issues. No one I spoke with suggested I do a clean install so I didn’t bother.