Introduction and Goals
Friday, May 14, 2010 at 5:21PM To begin I should note that is a project blog about a possible project I will be working on for the Clear Creek Amana School District, my current employer. The problem is that we need a good NAS system or file server that is capable of serving shared Windows and Mac network user home directories. What exactly we will need is as yet, an ambiguous idea as I am note sure yet whether we will be better off with a NAS or a fully featured file server. A brief list of goals and specifications will follows, these are likely to change as we experiment and better determine what, exactly we require.
Goals: What this system needs to accomplish
- Speed: File access times must be speedy. The Mac network home system with Open directory needs speedy access to many, generally small (< 10 MB) files such as preference files, plists and the like.
- Connection support: We must support a large number of simultaneous connections, typically between 150 and 250 connections with an average lifetime of about 90 mins.
- Protocol Support: At a minimum we need to support AFP, NFS and Samba sharing with support for AFP automount and spotlight searching.
- Rackmountable: The case must be rackmountable and be between 1 and 4 units in size.
- Hotswap Capable: We must be able to hotswap drives.
- RAID Support: At a minimum we must be able to support RAID 0, 1, 5 and JBOD.
- Network Interface: Network must be able to support many connections (see above) on 10/100/1000 cat 5.
- Storage: Initial storage should be at least 2 TB but needs to be expandable and reconfigurable.
- Reconfigurable: Although not strictly required it would be nice to be able to reconfigure the NAS to act as an HTTP server or as a DNS/DHCP box, log server, etc with little difficulty.
- Operating System: Operating system should be low cost, probably open source.
- Easy Interface: At a GUI level it should be possible to access the server via RDP or VNC, at a command level via SSH or telnet.
- Cost: Cost should be less than or equal to $1,000 total.
Comments and Concerns
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Operating system choice: it is beneficial to choose an OS that is both very light on resource use and configurable to our needs. This choice will define the box as a NAS or a fileserver. Free NAS is a possibility as is NASlite but I must be satisfied that these meet our reconfiguration, interface and protocol requirements.
- Speed issues: providing fast access to a number of small files over 150 - 250 connections poses some problems, I suspect at least 2GB of very fast ram would be a good choice. Perhaps we might be best served by running the OS on a small but speedy SSD for fast paging and to make sure that the OS overhead stays out of the way of file services. A well optimized TCP stack is also necessary, perhaps linux will do this well enough or perhaps we may need a bypass capable network card such as a gaming grade NIC.
- RAID controller: we will need a very robust and speedy raid controller, perhaps it would be more cost effective to get two smaller raid controllers rather than one big expensive one.
- AFP Support: AFP is not a very commonly used protocol outside the mac world (go figure)so supporting this may be a real problem, we will see.
- Cost: I really have no idea if this can be done for under $1000, and still be done well.
CCA, Goals, Introduction, NAS in Prebuild