Server tour: Storage


Shown in this image are three Ultra320 SCSI hard disk drives that are
located in one of our retired servers. SAS hard disk drives are
becoming more widely used than these types of drives nowadays.

A similar retention mechanism is used for 3.5-inch drives – press the maroon latch pull the handle and remove the drive.

This
image shows a low-cost (relative to enterprise standards) external
storage array. Towards the bottom of the image you can see
redundant array controllers which manage the three shelves of storage
above. The shelves are populated with FATA disks which are essentially
SATA drives with fibre-channel converters. We use this array for backup
purposes hence why (comparatively) low-cost FATA disks were used in
this array.

A close-up of the array shelves. Each shelf can contain 14 drives and
each 3.5-inch drive is hot-swappable
via a similar latch-and-handle design that is seen on 2.5-inch drives.
Three LED’s are also present on each drive indicating the status of
each individual drive.

The back of the three shelves of storage. Each shelf features redundant
power supplies and redundant fibre loop connectivity back to the
controllers (you can see these loop cables on either side of the power
supplies). The power supplies also feature redundant fan pairs (one is
installed in front of the other).

The back of the two array controllers. Only one controller is required
for operation but the second controller is installed for
fault-tolerance. Each controller has two fibre-channel ports each of
which connects to a different fibre channel switch (again for
redundancy one of these switches can be seen underneath the lower
controller). Each controller also has redundant power supplies.

Each server that needs to have access to logical disks in the array
needs to have a fibre-channel connection to one or both of the
fibre-channel switches (this choice is made depending on the level of
fault tolerance required). This video encoding server has a single
connection to one switch and is currently running at 2Gb/s.

Next: Managing the cables

The Full Tour
A typical rack server
Opening it up
Heatsink CPU and fans
Memory slots and graphics card
Power supply
The USB and LED panels
Storage options
Cables
Managing the server