Monthly Archive for May, 2009


File Copy Performance to USB Drive Oscillating Between Fast and Slow

I just had the “pleasure” of having to copy the contents of a terabyte USB disk to another similar USB drive. At first, I did not give this simple task much thought. I plugged the USB cables in and made my faithful Total Commander do the work. It did not take me long, though, to notice a strange phenomenon: the copy speed would oscillate between 8 and 24 MB/s. Continue reading ‘File Copy Performance to USB Drive Oscillating Between Fast and Slow’


Hard Links and Permissions / ACLs

Commenter Lee asked how ACLs are evaluated when an object has multiple hard links. I replied with comments of my own, which turned out to be wrong after I did some experiments. Here is what I found out about hard link permissions and believe to be true. Continue reading ‘Hard Links and Permissions / ACLs’


Cleaning up the Mess Left Behind by Multiple EFS Certificates

In case you have (un?)wittingly been juggling around with multiple EFS certificates like me, you may feel a strong urge to clean up the mess. Which mess? It can happen quite easily that different files are encrypted with different keys. In addition to that, directories that are marked for encryption have EFS certificates associated with them, and there is no UI to manipulate that. In order to straighten this out, once the proper certificate is in place each file and directory needs to be “touched” in order to update their encryption keys. Continue reading ‘Cleaning up the Mess Left Behind by Multiple EFS Certificates’


Tales from the Crypt – EFS and the Upgrade to Windows 7 RC

How can you mess up a simple OS upgrade by using encryption? Simple. Here is what happened to me when I upgraded my Windows 7 beta system to the RC version. Continue reading ‘Tales from the Crypt – EFS and the Upgrade to Windows 7 RC’


How to Find and List Unsigned Executable Files

Executable files can (and should be!) digitally signed. Without a digital signature you can never be sure the files on your hard disk have not been tampered with. There is really no exception to this rule, except maybe smaller open source projects that lack the budget to buy the digital certificate required for signing. Digitally signing executable files is so important that Microsoft made it a requirement in the Windows 7 Logo Program. One might think that such a simple yet important thing as signed executables can be taken for granted by now. Well, let’s have a look! Continue reading ‘How to Find and List Unsigned Executable Files’