Posted 21 September 2012 - 11:39 AM
I'm well aware of the performance hit. This is for a business client of mine who is trying to find out if some files were accessed by a (former) employee. Problem is, their backup device is smaller than their combined systems will allow, so they're compressing the entire volume onto the backup device (compression then copy, not copy then compress). My problem is that I don't want to dig into this if the compression will have altered the file modified and/or file access dates, and I'd rather just tell them "can't do it" than tear apart their hardware and cost them a bunch of money.
Since by nature compression involves opening up the contents of a file (not in an executable format but the file itself must still be opened to see the data it contains), modifying them (via compression), and then storing the file in a compressed format, logic would tell me that this would HAVE to affect the modified and accessed dates. One could even argue that the compressed result is a new file, thus changing the "create" date, though I can't imagine that's happening. If compression of a file affects its modified and accessed dates, and there's no audit trail in XP Home, that means we can't find what we're looking for. On the flip side, if compression does NOT affect those things, it makes me wonder what other changes can be made to a file without affecting them.