Undeletable Files on NTFS File System
Maintaining a web server on Microsoft Windows Server 2008 has mostly been straightforward and not very time-consuming. But recently I was confronted with a small but extremely annoying hassle, having to do with 3 files within the web server's area that could not be read, could not be deleted, and could not even be included within a .zip file. It was this last issue that first got my attention; I had been accustomed to .zip up the entire wwwroot area from time to time to ship it off-disk as a backup. This began to fail.
I knew right away that I had introduced the problem while attempting to administer permissions on Pmwiki, a third-party application written in PHP that was never intended to run on a Microsoft web server. Permissions for the upload folder kept reverting so that uploading attachments to the wiki failed, and it was while wrestling with this periodically recurring conundrum that I shot myself in the foot by somehow removing my ownership of those three files. To get around this boondoggle, I had made an entire new upload folder (from a backup), and just renamed the old "stuck" upload folder.
Then, the next time I tried my handy .zip-it-all-up backup trick, I got an error. The error, of course, happened right at the end of a long .zip process, and the entire archive failed to be created. I now had no off-disk backup happening, all due to these three "stuck" files, which I could see in the folder, but which I could neither read, delete, nor could I change permission on them. How anyone could deal with such problems without Google, I cannot imagine. Thank the universe for search engines.
Within minutes of beginning my search, I found this support page on Microsoft's site. At the very bottom, I found what I needed, which was the "if all else fails" strategy, which Microsoft called "Combinations of Causes" (that gave me a chuckle). This strategy required me to use a utility called "subinacl.exe" which the support page cited as being part of the Resource Kit.
Googling some more, I soon found that the Resource Kit was a very expensive (as in $300) book with tools on a disk in the back. I wasn't going to buy it. Then it occurred to me just to search for "subinacl.exe", and thankfully, I found that Microsoft had made it available as a download. So I downloaded it. But idiot that I am, I failed to note where it had installed itself (somewhere obscure, I promise you). Had to uninstall it, and then reinstall, this time noting down the install location, which for those of you going through the same thing, I will state here was C:\Program Files\Windows Resource Kits\Tools\.
So then I took a deep breath, constructed the command line that I needed in Notepad, then opened a command window, browsed to the obscure install folder shown above, and carefully pasted my unwieldy command into the window, then (holding my breath), I hit return. A frightening amount of techno babble appeared as the command executed. After a few tries, I got it to succeed, though it still gave warnings. I had to do this four different times, once for each file and then for the containing folder. The model command line is:
subinacl /onlyfile "\\?\c:\path_to_problem_file" /setowner=domain\administrator /grant=domain\administrator=F
View this joyful output here:
Altogether, the failures of Pmwiki and Microsoft file permissions have indeed cost me hours of hassle over the five years while I have managed the server. This latest offense was just the crowning jewel. Managing file uploads on IIS is a challenge at any time, as the web server really is leery of anyone writing into a file zone that it serves. But this doggy PHP open source piece of software (Pmwiki) that was tested only on Linux is, in retrospect, hardly worth the effort. I haven't tried installing other wiki software yet (no time for the learning curve!) but surely I hope there might be another one that works better than this when running on a Windows server.
Microsoft's support page did do the trick. The problem shouldn't be possible anyway. The big Administrator account should always be able to delete a file--what were they thinking?--but at least they provided the necessary utility to dig myself out of the pit. Still, I'm not exactly feeling kindly towards Microsoft at this moment. Or towards Pmwiki.
I knew right away that I had introduced the problem while attempting to administer permissions on Pmwiki, a third-party application written in PHP that was never intended to run on a Microsoft web server. Permissions for the upload folder kept reverting so that uploading attachments to the wiki failed, and it was while wrestling with this periodically recurring conundrum that I shot myself in the foot by somehow removing my ownership of those three files. To get around this boondoggle, I had made an entire new upload folder (from a backup), and just renamed the old "stuck" upload folder.
Then, the next time I tried my handy .zip-it-all-up backup trick, I got an error. The error, of course, happened right at the end of a long .zip process, and the entire archive failed to be created. I now had no off-disk backup happening, all due to these three "stuck" files, which I could see in the folder, but which I could neither read, delete, nor could I change permission on them. How anyone could deal with such problems without Google, I cannot imagine. Thank the universe for search engines.
Within minutes of beginning my search, I found this support page on Microsoft's site. At the very bottom, I found what I needed, which was the "if all else fails" strategy, which Microsoft called "Combinations of Causes" (that gave me a chuckle). This strategy required me to use a utility called "subinacl.exe" which the support page cited as being part of the Resource Kit.
Googling some more, I soon found that the Resource Kit was a very expensive (as in $300) book with tools on a disk in the back. I wasn't going to buy it. Then it occurred to me just to search for "subinacl.exe", and thankfully, I found that Microsoft had made it available as a download. So I downloaded it. But idiot that I am, I failed to note where it had installed itself (somewhere obscure, I promise you). Had to uninstall it, and then reinstall, this time noting down the install location, which for those of you going through the same thing, I will state here was C:\Program Files\Windows Resource Kits\Tools\.
So then I took a deep breath, constructed the command line that I needed in Notepad, then opened a command window, browsed to the obscure install folder shown above, and carefully pasted my unwieldy command into the window, then (holding my breath), I hit return. A frightening amount of techno babble appeared as the command executed. After a few tries, I got it to succeed, though it still gave warnings. I had to do this four different times, once for each file and then for the containing folder. The model command line is:
subinacl /onlyfile "\\?\c:\path_to_problem_file" /setowner=domain\administrator /grant=domain\administrator=F
View this joyful output here:
Altogether, the failures of Pmwiki and Microsoft file permissions have indeed cost me hours of hassle over the five years while I have managed the server. This latest offense was just the crowning jewel. Managing file uploads on IIS is a challenge at any time, as the web server really is leery of anyone writing into a file zone that it serves. But this doggy PHP open source piece of software (Pmwiki) that was tested only on Linux is, in retrospect, hardly worth the effort. I haven't tried installing other wiki software yet (no time for the learning curve!) but surely I hope there might be another one that works better than this when running on a Windows server.
Microsoft's support page did do the trick. The problem shouldn't be possible anyway. The big Administrator account should always be able to delete a file--what were they thinking?--but at least they provided the necessary utility to dig myself out of the pit. Still, I'm not exactly feeling kindly towards Microsoft at this moment. Or towards Pmwiki.
posted by Harbor Sparrow at
8:55 PM
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