Precisely what it says; the total loss of power required to maintain operational status of the server and / or storage system.
All storage devices should be connected to an uninterruptible power suppy (UPS) – preferably one that also protects against power spikes.
The sudden loss of power can have serious affects with storage – especially if the data resides on some form of RAID storage.
There is a distinct possibility that all files open at the time of power loss will succumb to some sort of corruption – and this is especially true of database files.
Power Surge
This is usually far more serious than a power failure, as it will often lead to physical component damage, including the internal components within hard drives, which often need to have the headstack replaced as the preamplifier (within the read/write headstack assembly) is one of the first components to blow.
Again, a decent UPS will prevent power spikes or surges from reaching your protected equipment. Not having a suitable UPS for your server and at least your main computers is data suicide.
