Occasional error writing to NAS

[derbas]

I have an occasional error that occurs when copying very large directories to a NAS. This is occurring under Windows 7 64-bit, to a Buffalo Tech Terastation live. What will happen is that an error will occur that says that the destination is write-protected. Once the dialog box is clicked, the entire operation will quit (i.e., there are no retries). I then need to use the synchronization command to find which files weren't copied -- invariably, the file that it 'failed' on will appear to have been copied (in terms of the same number of bytes written), but I need to recopy it to get everything to work correctly.

My 'guess' is that sometimes the NAS simply gets too busy, and sends a message that the disk is write-protected in order to stop the flow of data (this is only a guess). I have NOT had this happen when doing similar operations under other/previous operating systems, however, I just upgraded the disk drives in the NAS, so this can't be ruled out as a factor.

I don't know the 'root cause' of the 'write protection' error, but at the very least, it should fail by allowing one to either retry or skip the offending file, shouldn't it?

[derbas]

As a minor follow up, the 'copied' file (on the destination), while 'showing' the same number of bytes, has not been properly copied.

[ghisler(Author)]

Thanks for your report. Which copy method do you use (Configuration - Options - Copy/Delete)?

[derbas]

I'm using 'standard copy mode'.

[ghisler(Author)]

This is using the standard Windows copy function CopyFileEx. Normally CopyFileEx removes the target file when it encounters a copy error. Since the file is still there, it seems that the connection to the NAS is lost for a short moment.

[derbas]

That's entirely possible. Just by chance, I happened to glance at the screen once just before this occurred, and it showed something like a 'reconnecting' message (it happened so quickly I didn't get a good look). It may well be that the 'loss of connection' to the NAS is somehow re-interpreted as a write protection error of some type.

Given that, is there any way to have the copy function 'retry after delay' if hooked up to a network drive?

Bear in mind that the symptoms at this point are: a) file size on NAS destination is correct, b) file date/time is current date/time, not original file date, c) first portion of file contains correct data, then from a certain point until end of the file it is all zeros.

Any suggestions would be appreciated.

[derbas]

I should add that it is somewhat problematic even using the synchronize function, because the erroneous file on the NAS shows as a newer file than the original - and thus will then try to copy the 'bad' file over the 'good' file. Thus, I need to find the one file in the synchronization that is the bad one, and change the direction of the copy arrow, or I'm going to overwrite my good copy with the bad one.

[ghisler(Author)]

Well, there is nothing I can do if the connection really is lost. What you can try is to turn off the new 'standard copy mode' and return to TC's own copy function - maybe it shows a different behaviour. But the 'standard copy mode' itself cannot be improved by myself, because it's actually a Windows function, not my own.

[derbas]

Yes, I fully understand you can't change the copy behavior. I guess what I'm asking is if there is a way to alter the result of the failed write (which apparently is acted upon, after all it gives me the 'write protection error' message.

Possible things that would help:
a) option to delete (or attempt to delete) the partially written file
b) wait and retry the copy
c) some method of logging the actual failure to more carefully delineate it
d) if there is some method of determining that a network drive has disconnected, perhaps there are other methods I haven't thought of.

Total Commander is a wonderful program, I keep finding more and more I can do with it. I fully understand that whatever is going on is NOT the fault of TC, I'm just trying to find a way to make it 'more useful' while I try and uncover whatever the 'root cause' is.

[derbas]

Another follow-up: the failure ONLY occurs during a 'copy' operation. It has NEVER YET (operative word perhaps being 'YET') during a synchronization operation. I've had the error occur several dozen times now, but at this point they have all been during the initial copy operation, but not during any synchronize operation (and some of the synchronize operations have been for several hundred thousand files, spanning tens of gigabytes)

[derbas]

Well, I've just had my first failure during synchronization, so I guess that's not a true indicator of anything. Sorry for the false information.

[derbas]

Some more follow up: original setup was copying from a RAID5 array on a Win7-64 computer to the NAS. I wanted to see if changing computers and/or OS made a difference, so on a DIFFERENT computer, with WinXP Pro installed, and copying from an external USB drive (instead of the internal RAID array) to the same NAS, the errors still occur.

So, the upshot is that the 'root cause' issue must be something on the NAS (cause unknown, but probably related to some incipient problem with the disc drives that I just upgraded on the NAS, as this failure has never occurred in the past). However, it is still a 'problematic' issue for TC, in that when the 'write protection' error occurs, there is no ability to simply SKIP or RETRY and continue with the copy and/or synchronize operation. I hope that at some future time TC can simply address the issue of allowing this as an option, instead of simply 'quitting' with a message box, as it does now.

[bruce007]

I have been doing a copy from my old WD MyBook Live to the new Live Duo, and keep getting this error. Retry normally continues fine, but I have not checked the files are ok.
Not sure how this is a connection error, as the two NAS and PC are on same switch, all gigabit, and have no reported errors on the switch.
Also seems to be much worse when going NAS to NAS than PC to NAS, and more errors on the larger files.

But the part that is annoying, is there is no option to automatically retry or skip. Operation just stops and waits.

I am also using the standard copy. Might try the alternative suggested.
Will also double check that I don;t have dodgy copied filed.

[ghisler(Author)]

If it works with Explorer, you can use the Explorer copy mode (Configuration - Options - Copy/Delete).