On Fri, 2004-07-23 at 20:58, Ken Cobler wrote: > 2. KDE is nice, but, can be over-taxing on a system. I would suggest > using IceWM and configure just the menus and programs the students need > to run.
I use XFCE4 here for the same purpose - I find it's a nicer environment, and the users seem to get the hang of it quickly. As many of our users are largely computer illiterate, it's useful to have large, clear application buttons and a simple interface with minimal cruft. > 3. Though you are using SATA drives, you will not get the throughput > speed that SCSI can achieve. With SCSI you can strip and mirror your > drives (RAID-5). This is possible with SATA as well. With both SCSI and SATA, you need either a RAID-capable controller or software RAID to do this. > Stripping will improve the data throughput on a big > system that you are describing. My impression was that the system only had one disk (!!) for /home and another single disk for the rest, so there's nothing to stripe across. This fills me with horror personally, especially when combined with 'consumer' SATA disks. Disk failures are just too likely (esp given that many consumer disks are only designed for ~33% duty cycles) to accept without RAID. And if you can afford a dual Opteron, surely RAID isn't too much of an ask? My dual Xeon box barely has to work at all on the CPU side - it's bound almost entirely by the 2GB of RAM and the slow disk subsystem. To me, the OP's server seems rather unbalanced toward CPU at the expense of disk and RAM. > I would suggest SCSI RAID controller > (let the controller do the work), and RAID-5 (3 drives) + 1 optional spare. I have found that RAID 1 for my root partition, mail spools, databases, etc works well, with RAID 5 for the home directories and large archival storage. RAID 5's write performance makes it unattractive for databases and mail spools IMO. I suspect that a lot of the difference you perceive between the SCSI and SATA interfaces has little to do with the disk interfaces. Instead, it will be due to the higher spindle speeds (and hence lower seek times) that are standard on SCSI disks, the fact that tagged command queueing is universal on SCSI where it's currently rare on SATA, and the fact that you'll often be comparing SCSI hardware RAID with SATA software RAID (note that many SATA "RAID" cards are really just software RAID in the drivers, with a few BIOS hooks for boot) or RAID-less systems. The fact that SCSI disk firmware tends to be optimised for multi-user access, where many SATA disks have desktop-targeted firmware won't be helping either. My own SATA RAID based server's performance is less than stellar, but I'm using a first-gen SATA hardware RAID controller (real hardware RAID, but not overly great) with 'consumer' 72k RPM disks. That means disk firmware optimised for desktop use, no TCQ, low spindle speeds, and poor handling of heavy vibration conditions. I'd love to use WD Raptors or similar and compare them to a SCSI-based system, but the funds just aren't there. I think it's important to realise that there are "serious" SATA disks ( eg http://www.westerndigital.com/en/products/Products.asp?DriveID=65 ) and RAID controllers (eg http://www.3ware.com/products/serial_ata9000.asp ) out there, and not write off SATA based storage as a serious option. -- Craig Ringer ------------------------------------------------------- This SF.Net email is sponsored by BEA Weblogic Workshop FREE Java Enterprise J2EE developer tools! Get your free copy of BEA WebLogic Workshop 8.1 today. http://ads.osdn.com/?ad_id=4721&alloc_id=10040&op=click _____________________________________________________________________ Ltsp-discuss mailing list. To un-subscribe, or change prefs, goto: https://lists.sourceforge.net/lists/listinfo/ltsp-discuss For additional LTSP help, try #ltsp channel on irc.freenode.net
