May 2001 - openSUSE Edu - openSUSE Mailing Lists

RE: RAID Server
by Paul Munro 19 May '01

19 May '01

1GB certainly is a huge amount, and in terms of cost this could prove a bad business decision, let alone administration nightmare. That aside, this is your call. If you think the students/staff require on average around 1GB storage space, then obviously you are right in saying that a RAID server of some sort is required. I'm not sure that SCSI *is* the best choice, and there are now some excellent hardware based RAID cards that allow the use of IDE drives (Adaptec make a RAID solution for this). SCSI (especially 1TB worth!) would be *very* expensive, and though there are excellent technical reasons for still using SCSI in situations like this, the reasons themselves are becoming less imperative as IDE technology and throughput increases exponentially every year. Software RAID won't cut the chase in your situation, though a short test using it on a Linux server may tell otherwise, but will be expensive in time and resources. A hardware based solution in your case would be better and abstract the hardware/software for more redundancy. RAID 5 is another good choice, and although you'll lose a HDD for the extra security etc., it would be worth it if you are running such a huge storage space. Maybe you should consider a RAID server--though I don't think that the pricing would be in the same region as an Adaptec card and set of drives :-) I think you also mentioned the issue of concurrent connections? 100-150 isn't *that* bad, and I've worked on a school LAN where much more than that logged on at one time and the network didn't really seem to suffer much in the way of lag afterwards. The key is segmentation- and this is where switches come in. Make sure that you haven't placed *all* your machines on one segment and connected via a hub--probably (no- IS) a bad idea, especially because of those concurrent connections. Broadcasts shoot out in examples like this, and all sorts of bottlenecks creep out of the woodwork. If you are using DHCP, this becomes more of an issue- and again, segmenting your LAN with switches will keep traffic down and increase available bandwidth. Of course, as Michael Brown said, you could always make sure that students and staff log on to the LAN as soon as they enter the class...but I've tried that one, and some teachers just don't like that idea ;-) Good luck anyway!! Paul HNC, CCNA

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USB, IDE and linux
by Marcus Birkin 18 May '01

18 May '01

Ok, don't ask why but..... We have a Mac 7200/75 running SuSE 7.1, we wish to buy a PCI->USB card USB->IDE (e.g. http://www.addonics.com/product/usb.htm ) 40gb IDE drive can anybody recommend and advise me on the PCI->USB and the, USB->IDE and there use with Linux. Thanks Marcus Birkin

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Re: [suse-linux-uk-schools] RAID server
by Azrael Angel Of Death 18 May '01

18 May '01

>Over the next month or two I need to set up a server for my old >secondary >school to provide user storage for all the pupils. >There are just over 800 kids at the school, so I guess a total of about > >1Tb of storage would be sensible. >1Gb per child does not seem overly generous to me. Reality check?? What kind of school is this? --Azrael _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.

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RE: [suse-linux-uk-schools] RAID server
by Grainge, Derek 18 May '01

18 May '01

> so 1Gb per child does not seem overly generous to me. Fair 'nuf gov. We never have enough disk space :-) > RAID is a must, but IDE gives us a lot more Mb for our money than SCSI, > but maybe at the cost of performance/reliability? IDE devices, being cheaper, are certainly slower, and in some cases less reliable. These drives are going to be hammered. IDE devices are designed for home machines and don't stand up to the continuous use they get in servers. If you want a Tbyte, I think RAID/SCSI is pretty essential. Some SCSI disks are identical to their IDE equivalents except for the interface, but many are built using better technology (and last longer). > Nevertheless, it seems to me that even a modest hard > disc can outperform the 100MHz ethernet to which the server will be connected. Assume nothing. A single IDE drive would be a bottleneck. It's to do with the head seek times while possibly hundreds of files are open simultaneously, not the tranfer rate. Plainly multiple drives allow the OS to thread accesses much more efficiently (this was always a big selling point for Novell servers which handle such matters particularly efficiently). Plainly money is an issue. Please feel free to laugh: I think a 10 Mb network is insufficient for a Windows stations doing logons and accessing files from a server. I ran a network which was originally set up this way and it was SLOW. I think you need a mix of 10/100 to the stations, depending on what they're loading, and therefore you certainly need a backbone which is faster. I think a single 100 Mb net card would be a big bottleneck. Ideally you need a 1 Gb backbone with switches taking you down onto 100 Mb local segments. The server gets connected directly using a 1 Gb card. Failing which, with a lot of fiddling, you can use 2 or more 100 Mb cards in the server. You can physically subnet, or use IP subnetting to divide traffic. You are talking about lots of traffic and to plan for less might be economical but a mistake. My experience is that schools hammer networks much harder than most businesses do - schools push the envelope much harder despite the lack of budget. Prices for this kit are Mega but no longer astronomical. -- ******************************************************************************** All mail sent and received may be examined to prevent transmission of inappropriate attachments and certain obscenities. Wellington College does not accept responsibility for email contents. Problems to postmaster(a)wellington-college.berks.sch.uk. ********************************************************************************

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AS ICT
by Paul Taylor 18 May '01

18 May '01

Hi all: Has anyone out there taught mysql et al to A level students? Is it possible? I am about to teach my AS students their second ICT project and was hoping I could do something interesting on Linux rather than the usual Access stuff. Databases are not my forte and my students are struggling to get D grade projects in Excel so something very accessible (no pun intended) would be nice. Paul ptaylor(a)uklinux.net ------------------------------------------------------------ Free, BeOS-friendly email accounts: http://BeMail.org/ Free Peepshow - http://twinfusion.com/comic/peep/

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FW: [suse-linux-uk-schools] AS ICT
by Grainge, Derek 18 May '01

18 May '01

You don't say which platform your students are using. I'm assuming a Windows client talking to a Linux server? Or are you going to be Linux only? - in which case my comments below are irrelevant. Good things about using SQL: You can explain primary and foreign keys so much more effectively by demonstrating them. You can construct multi-table relational databases and play with views. Good things About Access: You can do the above, simply realising that a query is a view (effectively). I await flame from SQL purists. Access allows you to manage relationships graphically - as do some professional SQL implementations like Sybase. Therefore keys and integrity can be enforces just like in SQL. Using ODBC you can talk to an SQL database (most flavours of SQL are supported). If you are constructing SQL queries, you can switch to sql mode - and indeed you can write pure SQL if you wish instead of Access's "Query By Example". Bad things about SQL: You still need a front end, because half of a database project is going to be about the user interface. *** I would be interested in what people think is the best client interface to an SQL server *** I know there are many for both Linux and Windows platforms. I use both SQL and Access. On balance, and *for AS ICT project work*, I would use Access because it encompasses all of the requirements in one package. Educationally it's narrowing the focus, but it is a balance between getting good project grades and providing an idea of what goes on in industry (which generally is not Access). PS I do the AS course half-time over two years rather than full-time in one year - because I think it's easier to prepare students for practical work that way. We don't offer the A2. -----Original Message----- From: Paul Taylor [mailto:paul.taylor@bemail.org] Sent: 18 May 2001 08:46 To: suse-linux-uk-schools(a)suse.com Subject: [suse-linux-uk-schools] AS ICT Hi all: Has anyone out there taught mysql et al to A level students? Is it possible? I am about to teach my AS students their second ICT project and was hoping I could do something interesting on Linux rather than the usual Access stuff. Databases are not my forte and my students are struggling to get D grade projects in Excel so something very accessible (no pun intended) would be nice. Paul ptaylor(a)uklinux.net ------------------------------------------------------------ Free, BeOS-friendly email accounts: http://BeMail.org/ Free Peepshow - http://twinfusion.com/comic/peep/ -- ******************************************************************************** All mail sent and received may be examined to prevent transmission of inappropriate attachments and certain obscenities. Wellington College does not accept responsibility for email contents. Problems to postmaster(a)wellington-college.berks.sch.uk. ********************************************************************************

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RE: [suse-linux-uk-schools] AS ICT
by Grainge, Derek 18 May '01

18 May '01

> While on the general subject, I wonder if people have thought about > teaching python - its a wonderful language for getting started with. Hmmm ... I hear lots of arguments going on about c++ v. Java v. Python as starter languages. Actually no-one seems to have heard much about Logo for a long time - it has a lot of educational value despite the jokes made about Papert and all. This probably sounds like cold water, but it's really me expressing regret over the way education is going. I think there is little scope and certainly too little time to teach any programming language effectively within the context of an examinable course. The logic is that most students need to know nothing about languages, therefore all courses are about applications. The syllabuses for ICT make depressing reading. This is very short-sighted and is one reason (cost being the other) why many companies outsource their code develpment to places like India. There courses in their schools stick like a limpet to traditional Computer Science. -- ******************************************************************************** All mail sent and received may be examined to prevent transmission of inappropriate attachments and certain obscenities. Wellington College does not accept responsibility for email contents. Problems to postmaster(a)wellington-college.berks.sch.uk. ********************************************************************************

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Re: [suse-linux-uk-schools] AS ICT
by Azrael Angel Of Death 18 May '01

18 May '01

Information and Communication Technology _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.

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Parlez-vous?
by Derek Harding 15 May '01

15 May '01

Hi folks, A little light humour:- http://linuxanjou.free.fr/ping.html or regular reading (but in French):- http://linuxanjou.free.fr both hosted by the Unviersite d'Angers (http://www.info.univ-angers.fr/alp/) -- Best wishes, Derek Harding, (BA MIAP) ICT & Network Manager, Warlingham School hardingd(a)warlingham.surrey.sch.uk

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Re: [suse-linux-uk-schools] squid proxy help thanks
by sparkz 15 May '01

15 May '01

thanks to everyone for help. hmmm thought it might be to do with DNS. I have the machine set up as a DNS server but not a caching DNS server (because i never heard of one LOL) so if you know how to set one up or could point me in the right direction i would be gratefull. I've looked through all the config files but can't see any options that would change things. thanks sparkz

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