I need to build or buy a server in order to migrate a small business to its own infrastructure. The business has under 20 employees across 4 sites. Currently, the head office site (where this new server will be located) shares the same IT infrastructure with a sister company.
What the business needs the server to do:
- Host their low-traffic websites
- Host their SMTP/IMAP email servers, including and malware/spam filtering
- Host their Windows file shares
- Host backups/archives for their 3 satellite sites
- Not cost too much, say under A$5000
The plan:
- Buy a single server with good hardware virtualisation capabilities and a reasonable amount of redundancy
- Setup (at least) two virtual machines:
- one for any public-facing services (ie. web, email)
- one to host internal file shares and remote backups
- Use FOSS software for virtualisation and services, eg. CentOS, KVM/Xen, Apache, PostgreSQL, PHP, Postfix, etc.
- Do the storage/software setup myself (ie. I don't need the vendor's help with setting up the RAID or OS)
Design considerations:
- Hardware must be fully compatible with RHEL/CentOS 5.5 x86_64 (eventually the OS will be upgraded to RHEL/CentOS 6). This means no 3rd-party driver disks.
- Provide all services using virtual machines, for ease of administration (eg. snapshots, rollback)
- Connect the VM to dedicated LVM volumes on the VM host where applicable (eg. the file server), in order to avoid trapping company data in a VM (think of this as a poor man's SAN/NAS)
- Don't upgrade this server if more hardware resources are required in the future. Instead, look at building a SAN and perhaps adding a dedicated SAN NIC to this server through which it connects to the SAN
Hardware I'm considering:
- single-socket motherboard with VT-d support and built-in dual-port Gigabit Ethernet
- redudant power supply
- 4-core, Nehalem-based Intel Xeon with Intel VT and IOMMU support
- 12GB (3x4GB) 1333MHz single-rank RDIMMs
- 4x 3.5" drive bays holding 4x SATAII enterprise (ie. decent MTBF/IOPS) drives for full hardware RAID10 (aiming for an approx. 300GB logical drive). SAS would be nice, but it seems too expensive
- slimline DVD-ROM drive
- remote console with dedicated Ethernet port, eg. like DRAC/iLO.
- preferably cross-platform system management software (eg. monitoring, firmware updates, remote console). One vendor wants to sell me a Supermicro-based solution, but this seems to be Windows-only remote console, ie. it runs on Linux too but with only limited features.
- at least two spare PCIe slots for future expansion: one for the Ethernet to a SAN, and the other to a tape drive unit (this is assuming that the sytem or its RAID controller doesn't already have an external jack to attach a tape drive unit to). Note that a tape unit isn't required at this stage as backups will go to a remote over a VPN.
Questions:
- Can anyone forsee any problems with this setup or have any alternate recommendations?
- Does anyone already know of a specific server model which accomodates these requirements (either out of the box by some miracle, or with some customisation by the vendor)?
- Does anyone have any recommendations for a hardware vendor? Please keep in mind that this is a Melbourne-based business. At the moment I am considering Dell and Digicor. I would have included HP, but the boss isn't a huge fan of HP for some reason. The vendor needs to:
- be reputable
- be cost-effective
- have quick turnaround time for replacing faulty parts
- be able to build custom servers (ie. not just try and sell me some "cookie-cutter" system which doesn't quite meet my needs).
- Should I just build this myself? This doesn't seem like a popular option among sysadmins, because of the lack of support in case of a breakdown (eg. waiting weeks for the right part to be delivered).
- Which RAID controller model do I want?
- how much cache do I need, if any?
- do I need a battery-backed write controller (BBWC)? I don't think so because it's RAID10, not RAID5/6, but someone may know better
- is there some open RAID metadata format so that you can switch RAID controller vendors and still have your logical drive work?
- Is CentOS with KVM/Xen a good idea for the VM host? I can't see why it would be bad, but perhaps there are some horror stories out there.
- Do I want a dedicated NIC for each VM, or is a software bridge fine?
- Is there any particular motherboard chipset to get/avoid?
- Does it cost much more to get the same hardware as above, but a dual-socket board and 8 drive bays? I figure it's better not to get these to keep costs down. If I really need to upgrade, I still can (replace CPU, add RAM, attach to a SAN, etc.)
- Do I care how many rack units the system takes? I will have enough rack space for anything (eg. 1U to 5U), but is there a benefit to a certain size, eg. cost?