Dear Sergei, Many have already given good advice. A somewhat different approach:
You might want to consider using a NAS for user file and program storage. We have run a group of Linux PCs for years that way and we are quite pleased with it. The NAS would take the place of your file server PC. Although I don't quite have enough experience with it yet to fully recommend it, I do think you might want to consider using FreeNAS (just Google it), rather than buying a physical NAS. In a nutshell: 1) It is a free NAS setup, as the name suggests. 2) You need a PC with disk bays, a fair CPU and LOTS of memory. Add number and size of the disks you want. The PC generally should be a 64-bit system or else you will not be able to install enough memory. 3) You download the operating system on a USB drive (it does not go on your data disks) - this is very easy to do 4) Follow setup instructions and you are ready to start testing. FreeNAS offers many options, such as mirroring, striping etc. Different kinds of RAIDS are possible. My experience has been that it is very nice to have a RAID system that allows for one disk to go bad and you still have a working system. It has happened 2-3 times in 5 years, on 3 NASes combined, that we have had a disk fail without notice. The FreeNAS home page will lead you to all the RAID options you have, how "safe" they are, what the read and write performance is etc. It is a good idea to build a second system in a different building for backup. We use Rsync for backup at night and this works well (it is slow but it does not matter). You might want to do a resource analysis what your limiting factor is in processing crystallographic data. My experience is that the network generally is not the limiting factor and disk access generally is not the limit either - but it can be, if you are transferring a large number of images from a synchrotron. Typically, in my experience, CPU is still the limiting factor. Hope this helps. Mark -----Original Message----- From: Sergei Strelkov <sergei.strel...@pharm.kuleuven.be> To: CCP4BB <CCP4BB@JISCMAIL.AC.UK> Sent: Mon, Jul 29, 2013 4:22 am Subject: [ccp4bb] Advice on setting up / maintaining a Ubuntu cluster Dear all, In old times I, just like about any protein crystallographer, used to work on a cluster of SGI/IRIX workstations with complete NFS-based cross-mounting of hard disks. A typical operation included: 1. A single home directory location for every user: if my home directory was on workstation X, I would by default use it after logging on any of the workstations in the cluster. 2. A single location for all software for general use. (And, obviously, 3. The ability to log on any node from any terminal; today this is done via the 'ssh -X' command). I wondered if someone could give us an advice on a painless setup enabling 1. and 2., for a small cluster of Ubuntu computers. We (will) have about five similar Dell computers in a local (192.168.*.*) network (wired/wireless). Any tips on the hardware (especially the LAN and network disks) are also welcome. Many thanks, Sergei -- Prof. Sergei V. Strelkov Laboratory for Biocrystallography Dept of Pharmaceutical and Pharmacological Sciences, KU Leuven Herestraat 49 bus 822, 3000 Leuven, Belgium Work phone: +32 16 330845 Mobile: +32 486 294132 Lab pages: http://pharm.kuleuven.be/anafar
