Don't do it. Disk is cheap, and recovery is expensive.

And even though
the performance hit isn't huge, the increased risk isn't worth it. Plus it
means you can't use EFS anywhere on the volume, even if you need it.
--
Charlie.
http://msmvps.com/blogs/russel
"Jack" <dontaskwhoiam2001@newsgroup> wrote in message
news:01634850-ef86-4735-9bf2-ba4e751ad18d@newsgroup
> Dear all,
>
> I just added 2 x 600GB HDDs into a Dell PE2900 to form a RAID1 data
> volume.
>
> I am wondering if it is okay to tick the option "Enable file and
> folder compression" when formatting this new volume so that I can save
> more data on it. Are there any side effects to do this?
>
> Thanks
> Jack