Access Is Denied When Attempting to Put Files on FTP Server

ID: Q182626

The information in this article applies to:

Microsoft Internet Information Server version 4.0

SYMPTOMS

When you delete a file and then immediately copy a file with the same name to the FTP server, an "Access is Denied" error message may occur. The following command sequence will result in the "Access is Denied" error:


   PUT myfile.txt
   [file is transferred to FTP server]
   GET myfile.txt
   [file is transferred from FTP server to FTP client]
   DEL myfile.txt
   [file is deleted from FTP server]
   PUT myfile.txt
   [file is supposed to be transferred to FTP server,
   however, you will get an "Access is denied" message]

CAUSE

The FTP server caches the file handles of the deleted files that were previously fetched preventing their deletion. After a minimum cache sweep period, the file finally gets deleted when the cached file handle is closed. If the same file is put on the server before this minimum sweep interval has elapsed, the Put command fails with the "Access is Denied" error message.

RESOLUTION

To work around the problem, do one of the following:

After deleting the file, wait for a short time (about 30 seconds), and then copy (put) the new file to the FTP server.

-or-

Rename the file that is to be deleted, copy the new file to the FTP server, and then delete the renamed file.

STATUS

Microsoft has confirmed this to be a problem in Microsoft Internet Information Server version 4.0.

MORE INFORMATION

The following registry information may also be helpful in regards to this issue.

Please be aware that by adding the following registry information, you may negatively impact the performance of the FTP server.

If you want to completely disable file caching on your server, set the following parameter:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\InetInfo\Parameters\DisableMemoryCache DWORD 1

If you want to set a time value for caching set:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\InetInfo\Parameters\ObjectCacheTTL DWORD <value_in_seconds>

You can set these parameters under the following as well:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\W3SVC\ParametersHKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSFTPSVC\Parmeters

However, here is the hierarchy:

If a value is set under Inetinfo, then that is the value that is used, as this is the host for W3svc.dll and Ftpsvc2.dll. If you set the value under W3SVC, then this is used not only for W3SVC but also MSFTPSVC. Therefore, if you set the W3SVC ObjectCacheTTL to 120 (seconds) and the MSFTPSVC DisableMemoryCache to 1, then everything is cached for 120 seconds.

Try checking for these parameters (particularly a time value for ObjectCacheTTL) and test by adding the DisableMemoryCache key under Inetinfo to see if that resolves the issue.

Additional query words:

Keywords : IIS4Faq kbfaq
Version : winnt:4.0
Platform : winnt
Issue type : kbbug