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>From: Erick Lorenz <address@hidden> >Organization: UC Davis >Keywords: 200004072133.PAA04215 Sun diskless workstation Sunray ------- Forwarded Messages Date: Fri, 07 Apr 2000 14:34:09 -0700 To: address@hidden Subject: Diskless workstations and McIDAS I recently attended a seminar given by our math department in which they demonstrated and extolled the virtues of equipping a student computer lab with diskless workstations. They were able to assemble these units for about $400 (not including the monitor). Each station contains a PROM that boots the unit up to the point where it can then download Linux from a server. They each have enough memory to run Linux and any software without swapping over the network. They also used a dedicated LAN for internal communication. And of course the server(s) are very powerful with lots of disk space. This got me to thinking whether such a system could work with McIDAS. Unlike trying to run X-terminals off of a server, this gives each station its own CPU and memory resident software. Is there anything about the inner workings of McIDAS that would make this a bad idea? On the good side I can see (1) cheap hardware, (2) ease of maintenance, and (3) security. The math people related how crackers would find the addresses of the workstations and try to break in but couldn't because there was no local file system to mess with. What do you think? Erick Lorenz, UCDavis ------- Message 2 From: "James D. Marco" <address@hidden> Date: Fri, 07 Apr 2000 23:21:11 -0400 To: Erick Lorenz <address@hidden> Subject: Re: Diskless workstations and McIDAS Erick, I'm not much better with McIDAS than a novice. But, as a computer scientist, I'm not sure the trade off in network bandwidth, the added expense of a good server, and loss of general reliability (the server becomes a single point of failure for the entire lab) is worth it. I conceede that administrative chores will be easier. Yes, I am sure many people have different views, circumstances and priorities, so I'm sure there will be a lot of discussion here. My thoughts: 1) Expense - PC/Linux systems can be had quite inexpensivly. These include enough disk space & memory for McIDAS. The HP systems currently being 'pushed' on the network will not cost more than $500 (not including monitors.) For a 15 seat lab, the additional cost of the Server upgrades is apprximatly equal to the difference between diskless workstations and a PC based system. (Much of the cost savings of diskless workstations will be offset by the additional memory needed to prevent network swapping and the higher performance -cpu and disk- that is required.) 2) Maintenence - Depends on what you mean by maintenence. There are two forms: Individual machine and overall Lab. Hardware maint will be more with more full machines. But, in a stand-alone scenario, the reduncy of the stand-alone systems will give you greater overall LAB reliability and availaibility. The loss of a single machine, or perhaps a few of the machines, may force doubling-up by students, but the lab will not go down 'cuz a drive fails. In a diskless scenario, a hard-drive crash or motherboard failure will effectivly shut down the lab. Overall reliability in the lab will be much better with distributed stand-alone systems. This is an old arguement: Distributed System versus Centralized Server. There is no one answer that is totally best. (I use a couple of redundent servers, and independent workstations. Even if I loose the LDM server, the faculty/students can use old data till I perform a fail-over to the backup server.) Software maintenence is not as bad as you expect. A single image of a lab X-Station is all that's needed. They should all be identical with home directories mounted on the server. You need regular backups of the server and home directories, in either case. 3) Security - Slightly higher concerns with stand-alone systems because they ARE full computers, as you say. But, this is more of a maintenence concern. A hacked server in a diskless setup will, again, shut down the entire lab. (A good admin would shut down the lab if a hack was discovered, in either case. Soo, the actual difference in security is the implementation on 15 machines rather than one. But the 'identical image' should minimize this.) I have found that network bandwidth, even with 100BTX, more of a limitation than CPU/disk space. At 12-15 sessions of McIDAS over the nets to a single server, the network utilization is high enough to be a noticable slowdown. A diskless setup will NOT decrease net utilization. If/when I get McADDE running properly, it promises to relieve most of this. 'Jest my 2 cents...errruh...2 bits, now-a-days, jdm James D. Marco, address@hidden, address@hidden Programmer/Analyst, System/Network Administration, Computer Support, Et Al. Office: 1020 Bradfield Hall, Cornell University Home: 302 Mary Lane, Varna (607)273-9132 Computer Lab: 1125 Bradfield (607)255-5589 ------- Message 3 From: address@hidden Date: Sat, 8 Apr 2000 06:04:35 +0000 (GMT) To: "James D. Marco" <address@hidden> cc: Erick Lorenz <address@hidden>, address@hidden Subject: Re: Diskless workstations and McIDAS I have installed McIDAS-X and McIDAS-XCD sucessfully and have ran it on 3 in-house built (from pieces) 166 Mhz Pentiums running Solaris x86. It has always worked fine and these have been really bottom of the barrel machines. Our main machines are a 400Mhz PII and an Ultra Sparc but even the 400Mhz PII is by no means the bare minimum in my experience. My daily use machine is a 166 Pentium dualbooted with NT and Solaris. When I am in Solaris I run McIDAS and get data from the SPARC in the other room via the ADDE server (or data from our other machine in New Mexico). It works great and is imminently usable even on the old Pentium (IDE disk and 96MB RAM). The future of Solaris x86 always seems to be in doubt, but Sun has recently reaffirmed its support for Intel. I would give it consideration as well. I have built, installed and run McIDAS on Linux as well but have encountered bugs, quirks, etc that more experienced Unix-types can get around and probably enjoy tinkering with..but I find Solaris x86 to be a no pain deal. Much easier to get running perfectly right out of the box. I have really been happier with our Solaris Intel system than our Solaris SPARC (although it is really an Ultrasparc clone, not a genuine Sun). In short I agree with James, several minimal PC's should work great. Robert Mullenax ------- Message 4 From: "James D. Marco" <address@hidden> Date: Sat, 08 Apr 2000 08:38:29 -0400 To: address@hidden Subject: Re: Diskless workstations and McIDAS I probably should have described in more detail the setup I am using, my apologies. Robert described good workable system in some detail. Solaris is in use at Unidata. Hence McIDAS-X is a bit prejudiced towards it; if you do not have a lot of experience with some flavour of Linux, choose Solaris. (I am in the process of evaluating RH 6.2 and it seems a little more friendly than past versions. The downfall is the Gnome/Enlightenment GUI. It's way too ponderous for older machines. The old FVWM is MUCH easier on the CPU, faster on the system.) The difference between the two, otherwise, is cost...Linux can be downloaded for free. Soo much for OS. The main LDM/McIDAS machine is a P233 with 2 9g UWSCSI drives. This is capable of serving up to 12 simultaneous sessions of McIDAS. 4 of the sessions are set up as non-interactive batch jobs. The Fail-Over server is a PPro200, with 1 9g IDE drive. It mounts the LDM data over NFS and serves up to 8 McIDAS sessions out to the lab client machines. The network traffic is mostly here, since the display data is moved twice: NFS to the server, X-Windows traffic to the remote client. The client machines are a real mixed bag. All hand-me-downs from all over the campus. They range from old 486 to Pentium 200's. All run Windows NT with Exceed X software. BTW: My students are not usually Unix people, soo I have a script menu and batch files set up for them. I can make the files available if anyone wants them. Hope this helps! jdm James D. Marco, address@hidden, address@hidden Programmer/Analyst, System/Network Administration, Computer Support, Et Al. Office: 1020 Bradfield Hall, Cornell University Home: 302 Mary Lane, Varna (607)273-9132 Computer Lab: 1125 Bradfield (607)255-5589 ------- End of Forwarded Messages From: "Mike Schmidt" <address@hidden> Date: Tue, 11 Apr 2000 11:06:41 -0600 To: address@hidden Subject: SunRay clients Tom, I looked over the brief discussion regarding SunRay clients in the mcidas-x archives. There was a heated discussion about the same topic on comp.unix.solaris and the ease of management seems to emerge again and again as of the few positives. There seemed to be general agreement that if you have/use/like Xterminals currently, SunRay hardware is the next step to take... mike