Unix/Linux Pre-Install Questions to Ask and Answer
What is the purpose of your system?
Will a single system be enough (or SMP or cluster)?
Do you need to consider virtualization
(such as Vmware or Xen)?
Should you spend the money on SCSI, RAM, big disks, ...?
Should you use SANs, NAS, an internal RAID, or what?
Will you be building a network (such as SOHO or larger)?
What kind of network to get (if any)?
Where will you put the equipment (a server closet a.k.a.
What kind of racks to get? Wire supports?
What other equipment is needed (monitor switches, carts,
testers and monitors, ...), UPS, etc.
Do you have the correct physical systems (facilities) in place
or will you need to upgrade or add HVAC, fire suppression,
Some vendors will tell you to buy a large number of servers,
run the system awhile to see how it performs, and return the unneeded
servers for some sort of refund.
But there are other ways to estimate accurately the number of servers
required for some service(s) to run and provide a required average response
time (sometimes other performance requirements too).
Build a prototype system, measure performance and response time,
and extrapolate the required number.
Trust the vendor to only sell you what you actually need.
Estimate the resources needed for each part of the system
(e.g., web, forms, email, etc.) and sum these values to obtain
an estimate of the whole system requirements.
Calculate the value needed based on the factors of the servers
you are considering: number, type, and speed of CPUs per server,
amount and speed of RAM and disk system, network bandwidth
available, and the system's I/O performance data.
Hire an experienced consultant who does this sort of planning.
Speak with the former customers (from a year ago) to see that
they were pleased with the results.