I will be taking the main server holding home directories down for up to two hours Sunday to replace a failed drive in a RAID array.  No data is lost as the result of this drive being ill since all data is duplicated in the RAID array.  Things will be slower for the twelve hours or so after replacement as the RAID resync’s the new drive.  Because virtually everything depends upon home directories pretty much everything except private virtual servers will be out of service during this interval.