General help

 
 
Picture of Craig Smith
Linked files become "unreadable". Renaming the file and relinking "fixes" the file.
 

Hi

Periodically, we have a strange problem with our installation of 1.9.12. 

Individual links to files suddenly behave as if the file is corrupt when accessed via a resource (such as SCORM module, video in mplayer, PDF resource).  For example: A PDF will suddently act like a broken link and partially loads and hangs, a video will freeze on load or attempt to load infinitely, a SCORM module will stall at the start or part way through.

To solve this, we go into Files for the course (or into the folder on the server), rename the file (i.e. add V1, V2) and then change the resource to point to the renamed file.  The file will then work correctly until this occurs again days, weeks or months later.  There is nothing wrong with the file and the resource is still linked to exactly the same file only with a different name.

This is currently occurring with files across our site.  It is very frustrating for users and time consuming for us.  We thought it might be the antivirus software on the server and excluded moodledata from scanning, but this was not the cause.

Any thoughts  or ideas appreciated.

 
Average of ratings: -
I Teach With Moodle
Re: Linked files become "unreadable". Renaming the file and relinking "fixes" the file.
Group Testers

Strange indeed. Does this only happen on large files? When the issue is noticed, is it from within the LAN or outside? 

 
Average of ratings: -
Picture of Craig Smith
Re: Linked files become "unreadable". Renaming the file and relinking "fixes" the file.
 

Thanks for your reply.  Either inside or out, although users access from inside the LAN.   We are never certain when it happened as it is usually reported to use by a user who is having trouble with/cannot access the file.

The file size does not seem relevant.  For example, icons on the front page - which are only a few kilobytes in size - appear as broken links sometimes and simply renaming the file and then updating the URL in the HTML fixes the break.  SCORM modules that behave this way are several MB to 10s of MB.

It is weird.  I am at a loss to the cause.  We will be upgrading to the latest 2.x in the next few months and I'm hoping this issue does not come along with the upgrade. 

 
Average of ratings: -
I Teach With Moodle
Re: Linked files become "unreadable". Renaming the file and relinking "fixes" the file.
Group Testers

I'm intrigued. Have you explored the following?

  • error logs in your web server. Can you find an example of 'broken link' and see what error it returns (if any)
  • do you have hardware proxy on your network where files may become stale?
  • do you have a reverse proxy where the same might happen?
  • have you checked the permissions on the files that have an issue?
  • is the file actually 'broken' if you download it via FTP
  • how do you connect Moodle to the moodledata folder i.e. is it on the same physical server?

Could you also post a bit more information about your system? e.g. OS, web server, etc.

Cheers, 

Fred

 
Average of ratings: -
Picture of Craig Smith
Re: Linked files become "unreadable". Renaming the file and relinking "fixes" the file.
 

Hi Fred

Server OS is Windows Server 2008 with Apache/mySQL/PHP.   The server is dedicated to Moodle with no other web apps.

To your other questions:

  • There are no specific errors returned in the logs, although I will recheck this the next time it occurs.
  • I will need to check with our server team regarding the proxy setup on our network and get back to you.  The 'stale' proxy issue is not something I had considering and they will know more about this.  This would explain why renaming the file corrects the issue - it possibly forces a fresh copy of the file onto the proxy.
  • As above.
  • The permissions on the affected files are fine.  This does not seem to be a cause.
  • The file is still accessible in any other method including FTP or via windows explorer on the network or when logged into the server.
  • The moodledata folder is on the same physical server but on a seperate physical drive to the OS, webserver and application.

Thanks again for your interest.  I will talk to the server team regarding the proxy and let you know.

regards

Craig

 
Average of ratings: -