| Cut sheet diagrams | A rough diagram indicating where cable runs are located and the numbers of rooms they lead to. |
| Data recovery | Data recovery involves protecting data from loss. There are multiple methods to prevent data from being lost. Usually there is more than one method being used at the same time to protect the data. |
| Static, dust, dirt, and heat | Are envirionmental factors you must protect your network from |
| Power conditioning | Proctecting your equipment from irregularities in your building's electrical wiring. |
| EMI and RFI | Computer components, such as power supplies and monitors, as well as fluorescent lights, large electric motors, and electrical wiring, can cause Electro-Magnetic Interference (EMI) and Radio Frequency Interference (RFI) that can be picked up by other equipment and improperly shielded cables |
| Software viruses | A type of software that's sole purpose is to disrupt the operation of a network. |
| Peer-to-peer | The peer-to-peer network is also known as a workgroup network. It is designed for small numbers of workstations. |
| Client-server | Network operating systems are the heart of the client-server network. These systems control the resources and management of the local area network. |
Back up operations:
Full backup: All files on the disk are stored to tape and the
archive bit for all files is set to off.
Incremental backup: Backs up all the files that have been created
or modified since the last full backup. It is important to remember two
things about an incremental backup. One, that it only works in conjunction
with a full backup and two, that any file created or modified has its archive
bit turned back on so it will be saved to tape during the next incremental
backup.
Differential backup: Backs up all the files that have been created
or modified since the last full backup. This sounds the same as an incremental
backup, but the difference is that even though the file is saved to tape,
the archive bit is not reset. This means that each time a differential
backup is done, all of the files modified or created since the last full
backup will be stored again.
Copy backup: Backs up user selected files to tape. This backup
also does not reset the archive bit to off.
Daily backup: Backs up only the files that are modified on the
day of the backup. This backup also does not reset the archive bit to off.
Redundancy Techniques
RAID 0 Stripes data across multiple
disks, no parity, so there is no redundancy.
RAID 1 Disk mirroring (disk duplexing)
writes data to two identical partitions on separate hard disks thus creating
an automatic backup. Disk duplexing uses two hard disk controller cards
as well as two hard disks to prevent the controller card as being the single
point of failure for the system as in disk mirroring.
RAID 2 Writes data across multiple
hard disks, with error checking. This system is not used any more because
it requires expensive disk modifications to work.
RAID 3 Stripes data one byte at
a time and has a dedicated parity drive. A good, but expensive redundancy
choice. Because of the expense, this solution is not used very often either.
RAID 4 Stripes data one sector at
a time and has a dedicated parity drive. An expensive redundancy choice
that is very slow on data writes to the disk. Because of the expense and
the slowness of writing, this solution is not used very often either.
RAID 5 Stripes data and parity across
multiple disks (at least three for RAID 5). By mixing the parity across
all of the disks, a separate parity disk is not required and yet full data
redundancy is achieved. Data writes to the disk are still slow, but the
cost isn't so high. One other important fact about RAID 5 is that on a
Windows NT system the boot and system partitions cannot be located on a
RAID 5 disk array.