Add a page re virus scanners

[lazka]

• recommend adding msys2 to the exclusion list (with a warning re potential dangers)
• show how to add it to the exclusion list
• show some speed differences with and without active scanner
• Collect/show a list of errors caused by virus scanners, maybe link to https://cygwin.com/faq/faq.html#faq.using.bloda

[angelog0]

@lazka, when do you think to add that page? I added msys2 folder to exclusion list.. the things are a bit better, but just a bit... so I am curious to read your suggestions...

[lazka]

There isn't more that can be done except adding to the exclusion list, besides making sure that your builds (and temporary files generated by your build tool) are also contained in there.

There might be some potential to improve things by looking into/profiling pacman, cygwin etc.. but I'm lacking the skills/time there.

[angelog0]

@lazka, ok thanks.

An issue I find is this: I have a bash script which uses rsync -av --delete... to backup my HOME with a folder on an usb key ntfs formatted.. well adding MSYS2 to the exclusions shortens times for the backup but often they are long, too long, even with few files to synchronize... (5-10 minutes!)

[angelog0]

@lazka , Should we add some processes to the exclusions?

If yes, what do you suggest? and How? Just the name? for example, rsync or rsync.exe? Or what?