On Thu, Sep 17, 2009 at 4:09 PM, Neil Joseph Schelly <n...@jenandneil.com>wrote:
> I'm looking to build a small Shuttle barebone machine into a NAS running > Linux. The intent of the machine is to be a networked PC with lots of > storage in a RAID array, made available over the gigabit network interface > via Samba, NFS, and maybe iSCSI protocols. I'm curious what experience > others have with this sort of stuff in general, but two immediate questions > come to mind about processor and memory performance. > > I can go the low-power, low-heat route and get a single-core processor and > a > single memory stick of minimal quantity. Or I can upgrade a bit, get a > dual-core processor with 2 sticks of dual-channel memory. Or something in > between. What I don't know is how much impact processor speed, multiple > cores, memory capacity, and dual-channel memory has on disk I/O, network > I/O, > software RAID processing, etc. > > I like the idea of a small low-power, low-heat appliance, but will going > too > low on those negatively impact performance much? The cost difference > between > a single-core processor with 1GB of memory and a dual-core processor with 2 > sticks of 1GB dual-channel memory is insignificant, so that's not much of a > concern. > -N > _______________________________________________ > gnhlug-discuss mailing list > gnhlug-discuss@mail.gnhlug.org > http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/ > Any modern processor will be bored for these services, even if you use an encrypted and compressed file system. Single core will be plenty, but I don't know how much it will save you on power. Focus first on low power design and then on number of cores. You may find some multi-cores do better then some singles. The Intel Atom is probably your best bet and should still have plenty of spare processing power. OK, so MAYBE and Atom won't keep up with GigE if you use compression and encryption. It probably depends on the compression and encryption algorithms. I don't really know, but I bet you will be fine. Disk IO and then network are going to be your bottlenecks. More RAM will help disk IO via the OS's disk cache depending on the usage patterns of the data store, but most NAS appliances only have a couple hundred MB if you are lucky. If you are just using it for backups for steaming media, you can run very happily with as little as 64MB (assuming no GUI), but you may need more than that just to install the OS, depending on the distro. Higher RPM on disks will of course help IO, but not the power consumption. SSD will help both, but not your wallet. I like the Western Digital Green drives for this purpose as the only spin at 5400 RPM when they can get away with it and jump to 7200 RPM when the demand requires it. Compression will also help disk IO in most cases, and if you expect a lot of concurrent requests, play around with ionice on some of your NAS services. BTW, you might want to check out the FreeNAS project. From what I understand, there is nothing in there you can't get in another distro, but they keep it pretty lean while providing all the services you mentioned on a fresh install. Don't take my word for it though. It has been while since I looked into it. Ubuntu Server does a very lean install as well. Not quite as lean as Debian (and others), but even at the command line, I find Ubuntu is more friendly. I think there might have been a file server option on the Jaunty Server installer, but I don't pay much attention to such things as I like to to a bare install on a Server and pick the packges I want myself. Definitely a Samba option at install, but again, you might bet more than you need or want that way. SSH is a good option at install. You might also consider webmin if you are not hardcore on the command line. It will ask you if you want to install the relevant packages if it can't find a service when you access the module, so it makes a nice add on to a bare Ubuntu Server install. To install, use "dpkg -i webmin*.deb" then do an "apt-get -f install" when dpkg fails and apt-get will go fetch the dependancies and finish up the webmin install. Once webmin is running, you need not the command line any more. I have also heard very good things about ebox (Ubuntu only last I knew) but I have not been able to access it on my home server yet because the browser is puking on the cert for some reason and I have not cared to fight with it yet. That's my $1.37 (2 cents with inflation). -- Alan Johnson a...@datdec.com
_______________________________________________ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss/
