Using Autofs to mount CIFS share and busy files?

wernox · 04-29-2010, 11:10 AM

We have a homegrown process that runs on a windows box and produces a csv file. We mount the directory these are output to using autofs/cifs and then process them using a program on our linux database servers.

Is there a way from linux, looking at the cifs share, to tell if the target file is currently in use by a process on the windows box? We are having issues where an incomplete file is being processed occasionally.

zordrak · 04-29-2010, 11:51 AM

The problem is file locking. I don't know whether file locking exists between a cifs client and a windows server, I would guess it's up to Windows to handle it.

Perhaps using Services for Unix (SFU) on Windows to provide NFS to the linux client might make it happier?

catkin · 04-29-2010, 12:12 PM

Can you modify the "homegrown process that runs on a windows box" so that it writes the file with one name (say our.csv.part) and then, when it has finished writing it, renames it (to say our.csv)? That way the Linux system would be able to tell if Windows had finished writing it.

wernox · 04-29-2010, 01:30 PM

Thanks for the responses.

Unfortunately, I can only change the linux side of things. So changing the windows process isn't a course of action I can take.

catkin · 04-29-2010, 01:33 PM

Quote:

Originally Posted by wernox

Unfortunately, I can only change the linux side of things. So changing the windows process isn't a course of action I can take.

Less robustly the Linux side of things could note the file size, pause a while, check the file size and so on until the size was the same twice.

zordrak · 04-30-2010, 05:39 AM

Or test the modification time before and after the copy and discard and retry if it has changed..