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Dell PowerEdge 2800 RAID Configurations

The SCS Facilities recommended Server hardware for critical server functions is a Dell Poweredge 2800 (Tower), with an internal disk capacity of up to 2 Tb (approximate). Additional disk capacity (up to 2 Tb) can be added using an external RAID array. The Dell PE2800 is supported under Windows and Linux. The tower server contains eight hot-swap 1 inch disk drive bays with an integrated SCSI RAID controller (PERC 4) and backplane. In addition, there are two SCSI drive bays (the "media" bays) that can be used for a mirrored operating system disk array. The integrated dual channel RAID controller provides maximum flexibility for RAID configurations. The PE2800 only supports SCSI disks.

Supported RAID configurations include:

RAID 1

  • RAID 1 mirrors or duplicates the content of one drive onto another equally sized drive.
  • Mirroring provides optimal data integrity and immediate access to your data if one drive fails.
  • RAID 1 allows you to use only half of the available capacity of your disk capacity.
  • RAID 1 requires at least two hard drives and must consist of an even number of drives.
RAID 5
  • RAID 5 provides the best balance of data redundancy and capacity.
  • RAID 5 stripes all drives in the set into one large volume which can be partitioned accordingly.
  • An online "hot" spare is recommended as a reserve in case of drive failure.
  • Parity data size is equivalent to one of the hard drives.
  • If one hard drive fails, the RAID controller will rebuild the data on the online "hot" spare using the parity data and data from the remaining drives.
  • RAID 5 (with an online "hot" spare) requires at least 4 hard drives.
  • The total RAID capacity is the sum of all the hard drives minus the space of two drives when a hot spare is used.

Example configurations:
More Sample Configurations

Available Disk Sizes (7/2005):
36 Gb
72 Gb
146 Gb
300 Gb

Sample Configuration (configuration #1):

2 x 36 Gb Operating System (RAID1)= 36Gb
4 x 36 Gb Data (72 Gb + Hot spare) = 72 Gb

In addition to the internal RAID capacity listed above, SCS Facilities also supports and recommends external RAID arrays to add more capacity to servers. External RAID arrays are typically connected via a SCSI interface, but the hard drives in the array controller may be SCSI, IDE or SATA. Drive sizes from 72Gb through 400Gb are available in various drive types, and array controllers may hold from 8 to 16 drives. This gives a total capacity of several terabytes, depending on the configuration.

If your project needs a large amount of disk space, please contact SCS Computing Facilities for a quote.