It’s possible that the server will be down for a while at some point in the next couple of days. The second hard drive is reporting SMART errors which suggests an imminent failure. I’ve advised the hosting company of the problem and I’m expecting they will be replacing the drive in the next day or two.
Don’t panic if the drive fails before it’s replaced though! It only holds backups and archive copies of software/configurations, so whilst I wouldn’t want to lose it, it’s not a disaster if it does die.