Am Mittwoch, den 19.07.2006, 11:21 +0200 schrieb Andrea Reale: > Hi all, > For my first message on this mailing list, i will ask a question about > creating a ltsp system on ten 486s machines and a P4 1,5 Ghz as > server. I need this system for running applications such as openoffice > or firefox (it is for a school). Do you think is it possible to create > such a system with good performances? > Do you think it would be better (and possible) to run Xorg both on the > clients and server, or run Xorg only on the server?
486 as clients tend to be rather sluggish in display updating. I run a lab of 15 such machines (24M RAM each) off a 1.2GHz Athlon, and the first obvious factor with a single client logged in is the slow display updating. You most certainly want PCI graphics, to start with. If you can, do not use thinwire cabling. More than 16M RAM would be better as well (although 16M seems to be sufficient). I think our main problem is the slow thinwire networking (with ISA network cards) which makes the mouse react notably slow - quarter of a second delay or so in the moments when the network is under stress, like three machines booting at the same time or so. Recabling was not an option for us though - most probably that lab will be thrown out altogether soon and replaced by real thinclients ;-) The server will most probably slow down in the moment of Java / Flash / OOo firing up. For 10 users with heavy use OpenOffice, it is just a bit small - performance will be notably slower than having a single user sit at the same machine. However if you fit rather fast drives and a lot of RAM, this will help. Assuming you already have that machine, be sure to have proper drives in, not those slow old 20G drives on sale back when the thing was manufactured, their performance is MUCH worse than nowadays sold even 40G drives. As RAID (and SCSI) probably are out of discussion anyway, be sure to separate /tmp, /home from the main system - in my experience serving those from a second disc helps a bit in disk access delays. For getting a fealing of performance, setup the server and a single client. Startup OpenOffice and Firefox at the same time, close them immediately and open up again - look if the response time is OK for you (this is, for a single client). If that is already slow, you probably will not like the speed with 10 clients connected. If its OK, try fitting the rest and get some people use Office for a test hour or so. A few hints (0,02€ each): - Be sure to disconnect hard drives in 486 boxes - they spin up slowly and stop the system boot for several up to 15 seconds. - Fit AT THE LEAST 16 M to the clients, 24 would be better. Else they might crash with the X server running out of RAM. You might enable network swapping (just to be sure, you probably should even do so), but that must be the last resort, because it will seriously affect performance. We have been running stable with 24M for years, but I heard people complaining they needed network swap for 486 machines with 16M. - Have proper networking. PCI would be much better than ISA. Use twisted pair. I think 10M would be OK if used with a switch rather than a hub, but the server MUST have 100M, else you will suffer. - Get informed wether LTSP 4.2 still runs on 486, which I am not sure off. Our lab still is on LTSP 3: Never change a running system. - Get the graphics settings setup for 16bpp rather than 24bpp - And go for nothing more than 1024x768, if that is anyhow reasonable - For default settings, make those clients use screensavers that do not overly use graphics facilities. Black screen or logo is great, 3d animation probably is not. - And remove the too-much eyecandy in your desktop environment for performance's sake: When window rescaling results in flickering monitors, you most certainly want to just turn that feature off. A comment to your Xorg client/server question: In standard LTSP setups, the clients do run Xorg to have a graphics display (with the apps running on the server of course). That's fine. You could go for VNC instead, which saves client performance, but you will notice the additional delays induced by the VNC protocol, so just do not do that if the standard Xorg thing is at all possible. Hopefully you find even your small-scale devices make a suitable environment - it's most probably a great thing considered you don't need to spend much for a 10-seat network. Hth Anselm ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _____________________________________________________________________ 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
