Sometimes you're glad you spent that little bit more money on resiliency. Today is that day. I've just been informed by our ISP that one of the disks in the server that brought you this page has died and gone to hard disk heaven.
The last time that happened we had some bad downtime. Lesson learnt. If what's running on your server is in any way valuable to you then pay the extra money and get a RAID based server with disk mirroring. In these days of cheap SATA based RAID systems, disk mirroring is not expensive and one day you may be very thankful that you did.
Fingers crossed that the other disk doesn't die before Monday, when the disk is scheduled for replacement.