Lesson 20 Flashcards
A brownout occurs when the power that is supplied by the electrical wall socket is insufficient to allow the computer to function correctly. Brownouts are long sags in power output that are often caused by overloaded or faulty grid distribution circuits or by a failure in the supply route from electrical power station to a building.
brownouts
Advanced strip socket that provides filtered output voltage. A managed unit supports remote administration.
power distribution unit (PDU)
A battery-powered device that supplies AC power that an electronic device can use in the event of power failure.
uninterruptible power supply (UPS)
A Standby Power Supply fueled by diesel or propane. In the event of a power outage, a UPS must provide transitionary power, as a backup generator cannot be cut-in fast enough.
backup power generator
Specifications that support redundancy and fault tolerance for different configurations of multiple-device storage systems.
Redundant Array of Independent Disks (RAID)
Overprovisioning controllers and cabling so that a host has failover connections to storage media.
Multipath
A type of RAID that using two hard disks, providing the simplest way of protecting a single disk against failure. Data is written to both disks and can be read from either disk.
mirroring
A high-speed switching fabric used in SANs and data center networks.
Infiniband
Resiliency mechanism where processing and data storage resources are replicated between physically distant sites.
Geographical dispersal
Recovery of data can be provided through the use of a backup system. Most backup systems provide support for tape devices. This provides a reasonably reliable and quick mechanism for copying critical data. Different backup types (full, incremental, or differential) balance media capacity, time required to backup, and time required to restore.
backups
A backup type in which all selected files, regardless of prior state, are backed up.
full backup
A backup type in which all selected files that have changed since the last full or incremental backup (whichever was most recent) are backed up.
incremental backup
A backup type in which all selected files that have changed since the last full backup are backed up.
differential backup
Makes snapshot backups of files even if they are open. It is used for Windows backup and the System Restore and Previous Versions features.
Volume Shadow Copy Service (VSS)
A duplicate of an operating system installation (including installed software, settings, and user data) stored on removable media. Windows makes use of image-based backups and they are also used for deploying Windows to multiple PCs rapidly.
image
Copying the structure and contents of a physical disk device or logical volume to a single file, using a tool such as dd.
Imaging