Hardware Reference
In-Depth Information
differential backups several times a day—the only thing that using RAID
would buy us is a very limited protection against losing a very small amount
of un-backed-up data, and that only in the event of a hard drive failure.
Ultimately, we decided that the small benefits weren't worth the additional
cost and complexity of installing RAID. We decided to use nonredundant
SATA hard drives in our home server. By giving up the small additional safe-
ty factor provided by RAID, we'll gain more available hard disk space and
free up at least a couple of drive bays that can be used for later expansion.
Flexibility
Initially, our home server will be almost exclusively a file server. It will run
Linux, though, so at some point we may decide to add other functions to
the home server. To allow for that possibility with minimum disruption,
we'll configure the server initially with enough processor and memory to
allow adding functions incrementally without upgrading the hardware.
Expandability
When we set out to design our new home server, we considered building
it as an appliance system with an Intel Atom Mini-ITX board in a tiny case.
There are advantages to such a server. It's small and can be put anywhere,
and it doesn't consume much power, produces little heat, and doesn't
make much noise.
But we soon realized that for us the lack of flexibility inherent in a small
system outweighed its advantages. Looking back on how our last server
had grown and changed over the years made it clear that we wanted a
larger form factor for our new server.
Our last server was built in 2006, and originally had four 500 GB drives
installed, for a total of 2 TB of disk storage. We reached that storage limit
within a year, a lot faster than we'd expected. As a stopgap, we installed a
750 GB drive, for a total of five drives and 2.75 TB. As drive prices contin-
ued to fall, we replaced or added drives until we eventually ended up with
four 1 TB drives installed, and a total of 4 TB of storage. (We recycled the
500 and 750 GB drives as external hard drives for backups.)
That was where things stood when we set out to design and build our
new server. With 4 TB, we still had some available space, but the trend was
clear. The largest available hard drives when we designed our new server
were 2 TB, so we decided to start with three of those, for a total of 6 TB. But
we knew our storage requirements would continue to grow, so we want-
ed a system that we could expand to at least six or eight hard drives. With
3 TB drives on the near horizon, that means we can eventually expand this
server to a capacity of between 18 TB and 24 TB, which should hold us for
a while. (We're sure that in a few years we'll look back with amusement on
the days when we thought 24 TB was a lot of disk space.)
Networking
Of course, a server is useless if you can't get data into and out of it, so
we need fast, reliable networking support. Our current home network is a
mix of 100BaseT (100 Mb/s) and 1000BaseT (1,000 Mb/s, “gigabit”) Ether-
net devices that we're currently in the process of upgrading to exclusively
