Re: [SLUG] Home LAN and video
Bill wrote: Any suggestions re why the video and sound don't plat properly will be appreciated, as will suggested fixes for same. 1) If you're looking for network issues then ensure that all the PCs and all the switch ports are running ethernet autonegotiation. Under Linux check this by typing as root ethtool eth0 Within the output you should see Settings for eth0: Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Advertised auto-negotiation: Yes Speed: 100Mb/s Duplex: Full Auto-negotiation: on Link detected: yes Noting that the result is 100Mbps full duplex. Be very suspicious of any half-duplex results (usually the result of people's misunderstanding of how autoneg works). 2) You're running a sane house area network right? All in one big subnet, no VLANs configured on the switch. The addresses are assigned using DHCP so they've all got consistent gateway addresses and netmasks? -- Glen Turner Tel: (08) 8303 3936 or +61 8 8303 3936 Australia's Academic Research Network www.aarnet.edu.au -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] ubuntu samba appology
Thanks to the repondence. I seem to owe you an appology. What ever I tried with machine accounts yesterday failed. Today, after a good nights sleep, everything worked like a treat. sleep, sleep is good. Thanks again. Oh, and I do use encypted pwd's. always. Regards, Ashley -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] missing scsi tape drive
On Tue, 2005-07-19 at 14:09 +1000, Crossfire wrote:
David Gillies was once rumoured to have said:
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
ashley maher wrote:
I have an IBM xServer 226, with ServerRaid. dmesg does not detect the
scsi tape drive. More /proc/scsi/scsi finds the existance (ie model
number no details like it knows something is there not a clue what) of
the drive but not much else.
I think you'll probably get better results with hooking up the scsi tape
drive to the internal scsi controller instead of the serveraid
controller. Over my time working with IBM servers, we've always hooked
up scsi tape drives to a seperate controller as hooking them up the
serveraid has always been more trouble than its worth.
I'm also suspecting that nobody has even suggested that he ensures
that the 'st' module is loaded as /dev/{n,}st* nodes will not
exist/work without it, regardless if the drive is detected or not.
C.
thanks, this was suggested, and got me nowhere.
Unless I missed a step somewhere, but lsmod did return st* in the list.
Regards,
Ashley
--
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RE: [SLUG] Home LAN and video
Bill, I've not actually done direct DVD viewing of the network, but here is a few ideas. Firstly I believe that the maximum bitrate of the video+audio MPEG2 stream is around 6M bits per sec, which is around 600k Bytes per second on the wire. This shouldn't stress any network out (even plain old 10Mbps Ethernet half-duplex could do it at a stretch). Also you should be able to comfortably read at least 10M bytes per second from any disks that you have. You can easily confirm this raw performance by just copying a file that you are sharing (for instance one of your VOB files) to your local machine and working out the throughput. You could also use a tool such as iperf to verify the raw network performance, but I think the copy test should do what you want. The only thing that might be going wrong is that in the file transfer process there is going to be some lag when things get packetised for the network of some 10's of milliseconds. Now normally there is very little lag and certainly no variation in this lag (jitter) when you are reading direct from a local harddisk or DVD. (The test above doesn't measure jitter only average throughput. Iperf can measure jitter, but I don't wouldn't expect it to reveal much on your LAN). From what you are saying, it seems that the problem is that the DVD client application is not network aware (it just sees a file path or drive letter) and hence occasionly when it goes to play a frame of video or sound it just isn't there yet, simply because the server isn't tuned to respond with a repeatable and constant response time. What you really need I believe is to stream your audio or video. This way the application will know the data is coming via a network, expecting delay and jitter, and hence set up a jitter buffer to accommodate for the variation in arrival time of frames. The most common app to do this on Linux is VLC. This can present your DVD as an uncoverted stream (at the same bit rate as your DVD) but still allow the client to deal with network anomolies. Anyway, hopefully someone with some more experience can confirm or deny my suppositions! Regards, Martin Martin Visser, CISSP Network and Security Consultant Consulting Integration Technology Solutions Group - HP Services 410 Concord Road Rhodes NSW 2138 Australia Mobile: +61-411-254-513 Fax: +61-2-9022-1800 E-mail: martin.visserAThp.com This email (including any attachments) is intended only for the use of the individual or entity named above and may contain information that is confidential, proprietary or privileged. If you are not the intended recipient, please notify HP immediately by return email and then delete the email, destroy any printed copy and do not disclose or use the information in it. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bill Sent: Tuesday, 19 July 2005 2:10 PM To: slug@slug.org.au Subject: [SLUG] Home LAN and video I have a home LAN with 1 PC as a file/print Server ( using Clarkconnect) and 2 PCs as Workstations, both running Kanotix/Debian and dual booting to Win XP Pro. I have ripped a couple of movie DVD's to .iso files and copied them onto the Server. When I play them back on the Workstation PCs, either under Kanotix or XP, the video is jerky and the sound stutters/drops in and out. All PCs are Athlon XP 2400 or faster with either 512k or 1gb ram, with onboard 10/100mbs ethernet. My ethernet switch is also 10/100 and all cabling is Cat5. The Server is about 12 meters from the 2 PCs. Any suggestions re why the video and sound don't plat properly will be appreciated, as will suggested fixes for same. Bill -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Qemu Questions
Peter Rundle wrote: 1. Having trouble getting the network going. I have interface tun0 up with the same IP as the guest machine. This IP is pingable from the network, however the guest machine cannot see the network. I assume that the Linux host is responding to the pings. I might be misunderstanding you but the tun0 interface should have a different ip, e.g I use 172.20.0.1 for tun0 and 172.20.0.2 for the guest. sudo /sbin/ifconfig $1 192.168.1.146 I couldn't get sudo to work with $1 so I just used tun0. 2. When I run the guest pc using loadvm the cursor is black!? I.E Haven't tried that. 3. I've configured the guest PC (nt4) to turn-off after shutdown, but qemu simply restarts the machine. Does anyone know of a way to have the guest shutdown and have qemu exit once the guest is turned-off? Don't know, doesn't do it here either. Geoff -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Pros Cons of Unix databases
On Tue, Jul 19, 2005 at 11:20:22AM +1000, Peter Chubb wrote: Howard == Howard Lowndes [EMAIL PROTECTED] writes: Howard Can anyone provide pointers to good reading material on the Howard comparisons between the various Unix databases. Peter Chubb: I'm interested in this too. The general impression I get from `real' users is that Oracle is the only choice for a serious database app at the moment. Personally, I'd prefer to use an open-source engine; but then you have Postgres as the only serious contender. Msql and mysql, SQlite, grokbase, etc., are fairly limited (although reasonably fast for small-scale use). At least, that's my impression. For very large sites, expensive if things go wrong, I've seen Oracle and several years ago, Informix used. Informix especially on SCO. Mysql would have been out of the question years ago, with no support for transactions. Now, I'm not so sure. The impression I get with Oracle is that it is safe bet, and risk aversion is one of the priorities for many people. The major thing that a database is used for, especially in web apps. is concurrancy control. This is a huge issue with the numbers of users and numbers of hits that large sites have. This document, I think, gives a pretty good roundup of the kinds of sites that have grown up. http://homepages.inf.ed.ac.uk/wadler/Service%20Architectures.doc (Unfortunately the graphics don't scale properly in OpenOffice, but they are very worthwhile.) I hope to base some of my talk on Apache2, large sites and concurrancy on some of it. The author makes the point that everyone starts off treating the db as a 'blackbox' sql engine, with interfaces such as perl dbi, but before long starts to integrate more and more into things like PL/SQL and embedding special constructs in their application code. That's been my experience too. However, I despair of SQL databases. They don't have rich expressions, their performance is hopeless. Many a warehouse, accounting and invoicing systems are still run on Pick/Universe. As for small scale use, I think databases are often used when they shouldn't be. The filesystem is a pretty good database too, Just my 2c. Jamie -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] cfengine DNS
Richard Heycock wrote: I'm trying to set cfengine to copy a file from one host to itself and I keep getting the error Server returned error: Host authentication failed. Did you forget the domain name. Which it seems is due to me not having reverse mapping on my DNS server. it seems the short answer is no. google says: http://cfwiki.org/cfwiki/index.php/Cfengine_Protocol for a simple DNS solution, dnsmasq might give you pretty easy forward and reverse for your needs. dave -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] cfengine DNS
On Tue, 2005-07-19 at 21:36 +1000, David Kempe wrote: Richard Heycock wrote: I'm trying to set cfengine to copy a file from one host to itself and I keep getting the error Server returned error: Host authentication failed. Did you forget the domain name. Which it seems is due to me not having reverse mapping on my DNS server. it seems the short answer is no. google says: http://cfwiki.org/cfwiki/index.php/Cfengine_Protocol The thing is I've already copied the public keys over. From Reverse DNS Lookup: ... If the server already has the public key of the client, then it is not necessary to do the reverse DNS lookup, since the validity of the client's identification will be revealed during the challenge-response section of the authentication protocol. The server public is in ppkeys on the client and the client public key is on the server. They won't even come anywhere close to talking to each other if there not. In addition to this I've set up the reverse mappings in my dns server and it still doesn't work. There seems to be nothing I can do to make it work. Thanks for the site, though, it looks pretty good. I think it's time to get on the cfengine mailing list. rgh for a simple DNS solution, dnsmasq might give you pretty easy forward and reverse for your needs. dave !DSPAM:42dce61f190551942928804! -- Wickedness is a myth invented by good people to account for the curious attractiveness of others -- Oscar Wilde Richard Heycock [EMAIL PROTECTED] key fingerprint : 909D CBFA C669 AC2F A937 AFA4 661B 9D21 EAAB 4291 -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] [OT] What tools for an automatic control system
Dear list, I am thinking about creating an automatic control system. The main purpose is to maintain an established relationship between say, temperature and pressure. E.g. If the temperature is too high, reduce pressure There will be a number of real time data feeds. 1. Would it be better if each data feed / sensor had it own independent 'agent' / servlet to monitor its function or is a single integrated system to monitor all the sensors? 2. What free tools exist to monitor systems? Any other suggestions. -- Richard Hayes Nada Marketing PO Box 12 Gordon Australia 2072 Tel: +(61-2) 9412 4367 Fax: +(61-2) 9412 4920 Mob: +(61) 0414 618 425 www.nada.com.au -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] Problem with iptables (also with Slug archives)
Good morning all I'll start with the 2nd thing. Everything I type into the search engine for Slug archives this morning results on zero items returned. Back to the first problem. My problem with iptables is that, for only one particular web site it doesn't seem to recognise that the return packets are related to my own computers original requests and is thus blocking access to that particular site. Following is a snippet from ethereal. reading from file pp1, link-type LINUX_SLL (Linux cooked) 05:53:58.169345 IP 203-206-243-100.dyn.iinet.net.au.32768 dns.iinet.net.au.domain: 46458+ A? www.patchworkprovisions.com.au. (48) 05:53:58.419363 IP dns.iinet.net.au.domain 203-206-243-100.dyn.iinet.net.au.32768: 46458 1/2/0 A 72.41.32.224 (116) 05:53:58.419536 IP 203-206-243-100.dyn.iinet.net.au.33086 72.41.32.224.www: S 2119897742:2119897742(0) win 5440 mss 1360 05:53:58.676015 IP 72.41.32.224.www 203-206-243-100.dyn.iinet.net.au.33086: S 1947729371:1947729371(0) ack 2119897743 win 5840 mss 1400 05:54:01.418789 IP 203-206-243-100.dyn.iinet.net.au.33086 72.41.32.224.www: S 2119897742:2119897742(0) win 5440 mss 1360 05:54:01.671964 IP 72.41.32.224.www 203-206-243-100.dyn.iinet.net.au.33086: S 1947729371:1947729371(0) ack 2119897743 win 5840 mss 1400 05:54:01.677841 IP 72.41.32.224.www 203-206-243-100.dyn.iinet.net.au.33086: S 1947729371:1947729371(0) ack 2119897743 win 5840 mss 1400 05:54:07.417848 IP 203-206-243-100.dyn.iinet.net.au.33086 72.41.32.224.www: S 2119897742:2119897742(0) win 5440 mss 1360 As you can see my computer makes a DNS request, gets an answer, then makes the SYN request to the website and receives the ACK. It just goes on making the SYN's because the ACK is blocked by iptables. In the following snippet from a www request to cisco all works fine reading from file cisco, link-type LINUX_SLL (Linux cooked) 06:07:33.182686 IP 203-206-243-100.dyn.iinet.net.au.32768 dns.iinet.net.au.domain: 59737+ A? www.cisco.com. (31) 06:07:33.216451 IP dns.iinet.net.au.domain 203-206-243-100.dyn.iinet.net.au.32768: 59737 1/2/1 A www.cisco.com (99) 06:07:33.216770 IP 203-206-243-100.dyn.iinet.net.au.33119 www.cisco.com.www: S 2986197184:2986197184(0) win 5440 mss 1360 06:07:33.432785 IP www.cisco.com.www 203-206-243-100.dyn.iinet.net.au.33119: S 4025776358:4025776358(0) ack 2986197185 win 8192 mss 1400 06:07:33.432849 IP 203-206-243-100.dyn.iinet.net.au.33119 www.cisco.com.www: . ack 1 win 5440 06:07:33.433116 IP 203-206-243-100.dyn.iinet.net.au.33119 www.cisco.com.www: P 1:552(551) ack 1 win 5440 If I turn off firestarter the problem goes away immediately. However this is not a safe solution. I have tried specifically allowing inbound packets from that ip address but that doesn't seem to work either. The setup is Ubuntu Hoary kernel 2.6.10-5. Can anyone suggest the cause of this problem Thank you and regards Steven -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Qemu Questions
On Tue, 19 Jul 2005 19:18:38 +1000 Geoff Reidy [EMAIL PROTECTED] wrote: SNIP 3. I've configured the guest PC (nt4) to turn-off after shutdown, but qemu simply restarts the machine. Does anyone know of a way to have the guest shutdown and have qemu exit once the guest is turned-off? Don't know, doesn't do it here either. I'm running Windows 95 under qemu and it shuts down just like it should. I haven't tried networking or any of the fancy stuff since I just use it for running some legal research CDs. It's neat for that because of being able to use the .iso image of the CD. Alan Geoff -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html -- Alan L Tyreehttp://www2.austlii.edu.au/~alan Tel: +61 2 4782 2670Mobile: +61 428 148 071 Fax: +61 2 4782 7092FWD: 615662 -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Qemu Questions
Geoff Reidy wrote: I couldn't get sudo to work with $1 so I just used tun0. Could you possibly give an example sudoers entry? I'm stuggling with sudo (never used it before). Thanks P. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] [OT] What tools for an automatic control system
Richard Hayes wrote: Dear list, I am thinking about creating an automatic control system. The main purpose is to maintain an established relationship between say, temperature and pressure. E.g. If the temperature is too high, reduce pressure You need to specify a bit more about what accuracy of control you need and what response time is required. Simple on/off control (e.g. temp over x Celsius so reduce pressure by y milliBars) could be done via some simple code on a serial line. But if you have a need to limit overshoot and require accuracy then you might need Proportional- Integral- Derivative (PID) control. http://www.netrino.com/Publications/Glossary/PID.html That is much harder and would probably require you to use a pre-written library. There will be a number of real time data feeds. 1. Would it be better if each data feed / sensor had it own independent 'agent' / servlet to monitor its function or is a single integrated system to monitor all the sensors? 2. What free tools exist to monitor systems? Don't know. Any other suggestions. Things like LabView or LabNoteBook are setup to do this. They have a GUI programming environment and have PID control algorithms. Using those would be much easier. Ask them for the Linux version. Mike -- Michael Lake Chemistry, Materials Forensic Science, UTS Ph: 9514 1725 Fx: 9514 1460 [pls ignore idiot lawyer's msg below] -- UTS CRICOS Provider Code: 00099F DISCLAIMER: This email message and any accompanying attachments may contain confidential information. If you are not the intended recipient, do not read, use, disseminate, distribute or copy this message or attachments. If you have received this message in error, please notify the sender immediately and delete this message. Any views expressed in this message are those of the individual sender, except where the sender expressly, and with authority, states them to be the views the University of Technology Sydney. Before opening any attachments, please check them for viruses and defects. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Qemu Questions
James Gregory wrote: I have actually had this working in the past, but I remember it being a huge amount of effort. I don't know if you can get away with it for what you need to do, but the user-net option is much simpler to get going. I suggest you try that; it will at least tell you if your guest OS is setup correctly. It will also let you run it as a normal user. Err ok I thought that user-net option didn't actually give the PC network connection. The documentation on qemu that I found so far is pretty thin, just enough to get an expert going, not being one of those I'm stuggling a little. So does the user-net option actually give you network connectivity and if so why would anyone bother with the other method? Also, which version are you running? The 0.6 version had a bug with networking, though I don't recall the details. 0.7 I've seen that before, presumably because it doesn't try to redraw until something writes to its video memory region. It generally works ok once there's been some activity on the guest OS. Is this not the case for you? No moving the mouse etc, even the busy hourglass cursor is black. It all works it's just black, not that there's anything wrong with being black ;-) Thanks Pete -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] Video Editing Software
Does anyone know of any decent video editing software for linux? I just have to do some simple resampling (lower frame rate to 15fps, currently 30) and resizing of videos (from 640x480, to something less). They are currently in quicktime format (straight of the digital camera), and I want to convert them to DivX, or something smaller so I can put them up on our band's website. Thanks, Luke -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] Re:Video Editing Software
There is a story on video editing on LinuxToday http://software.newsforge.com/software/05/07/08/140221.shtml regards, - Richard Hayes Nada Marketing PO Box 12 Gordon Australia 2072 Tel: +(61-2) 9412 4367 Fax: +(61-2) 9412 4920 Mob:+(61) 0414 618 425 www.nada.com.au -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Pros Cons of Unix databases
my 2c, MySQL supports transactions. Supports everything needed even for large scale projects, unless you plan to start a new Yahoo.com, *maybe*. Oh, and last time I heard (which may not be accurate by now), Yahoo Finance was using it. It supports replication. If you're wise, you'll put the write operations in ATA SCSI disks, **properly configured** via hdparms, using a kernel optimized for that kind of operation. Splitting an application reads through different servers helps as well. It's *easy* to be done. Larga scale applications *should* split their requests, or at least have this as a feature (off or on). The service scales easily. It comes with the resources for that. It's a matter of using it. MySQL isn't different that most FOSS around: the vanilla package was made to work in most scenarios. If you download it binary, run, and expect it to handle billions of records, you have the wrong idea of how stuff works in this world. Same logic as if you're dealing with, say, Apache, or even Linux. There's a book around called High Performance MySQL, from O'Reilly. It isn't great only because all that info can be found for free, but if you're not willing to search, buy it, and put the knowledge in practice. If you're willing to become the expert, do the same with kernel optimizations. Then you'll eventually know how to shape an OS for hosting a database for large scale projects. By that point, you'll realize you don't need to pay licenses for commercial databases, who actually do all the forementioned through wizards. If you're not willing to become one, then get somebody to do it. I'm sure you'll spend less than you would with a license for an Oracle db. It *will* handle large scale projects. On 7/19/05, Jamie Honan [EMAIL PROTECTED] wrote: On Tue, Jul 19, 2005 at 11:20:22AM +1000, Peter Chubb wrote: Howard == Howard Lowndes [EMAIL PROTECTED] writes: Howard Can anyone provide pointers to good reading material on the Howard comparisons between the various Unix databases. Peter Chubb: I'm interested in this too. The general impression I get from `real' users is that Oracle is the only choice for a serious database app at the moment. Personally, I'd prefer to use an open-source engine; but then you have Postgres as the only serious contender. Msql and mysql, SQlite, grokbase, etc., are fairly limited (although reasonably fast for small-scale use). At least, that's my impression. For very large sites, expensive if things go wrong, I've seen Oracle and several years ago, Informix used. Informix especially on SCO. Mysql would have been out of the question years ago, with no support for transactions. Now, I'm not so sure. The impression I get with Oracle is that it is safe bet, and risk aversion is one of the priorities for many people. The major thing that a database is used for, especially in web apps. is concurrancy control. This is a huge issue with the numbers of users and numbers of hits that large sites have. This document, I think, gives a pretty good roundup of the kinds of sites that have grown up. http://homepages.inf.ed.ac.uk/wadler/Service%20Architectures.doc (Unfortunately the graphics don't scale properly in OpenOffice, but they are very worthwhile.) I hope to base some of my talk on Apache2, large sites and concurrancy on some of it. The author makes the point that everyone starts off treating the db as a 'blackbox' sql engine, with interfaces such as perl dbi, but before long starts to integrate more and more into things like PL/SQL and embedding special constructs in their application code. That's been my experience too. However, I despair of SQL databases. They don't have rich expressions, their performance is hopeless. Many a warehouse, accounting and invoicing systems are still run on Pick/Universe. As for small scale use, I think databases are often used when they shouldn't be. The filesystem is a pretty good database too, Just my 2c. Jamie -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html -- Julio C. Ody http://rootshell.be/~julioody -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
RE: [SLUG] [OT] What tools for an automatic control system
Hi, It depends on the rate of change and response that you need. You mentioned real time, so I assume you need something close to analog control gear in terms of response time. In a closed system (that is, you know how big it will get, it won't get any more inputs/outputs in its lifetime), you can calculate what sort of response time you will get if you have one monitor for several inputs, assuming all inputs are changing. In a variable system, where you are adding or removing i/o, you may be better served with a 1:1 relationship between input and monitor. This becomes more critical in the case of safety control systems, but is less of an issue if it is just the garden lights. For control and feedback mechanisms you might want to brush up on some control theory and maths if you want to avoid oscillatory systems. Sorry I can't advise you on free tools; my control systems were in microcontroller assembler or C (many microcontrollers come with A/D and D/A converters), but I think you could get away with 'dd' from the command line if your device has a driver... Cheers, Jill. -Original Message- From: Richard Hayes [mailto:[EMAIL PROTECTED] Sent: Wednesday, 20 July 2005 6:31 AM To: slug@slug.org.au Subject: [SLUG] [OT] What tools for an automatic control system Dear list, I am thinking about creating an automatic control system. The main purpose is to maintain an established relationship between say, temperature and pressure. E.g. If the temperature is too high, reduce pressure There will be a number of real time data feeds. 1. Would it be better if each data feed / sensor had it own independent 'agent' / servlet to monitor its function or is a single integrated system to monitor all the sensors? 2. What free tools exist to monitor systems? Any other suggestions. -- Richard Hayes Nada Marketing PO Box 12 Gordon Australia 2072 Tel: +(61-2) 9412 4367 Fax: +(61-2) 9412 4920 Mob: +(61) 0414 618 425 www.nada.com.au -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html -- IMPORTANT NOTICES This email (including any documents referred to in, or attached, to this email) may contain information that is personal, confidential or the subject of copyright or other proprietary rights in favour of Aristocrat, its affiliates or third parties. This email is intended only for the named addressee. Any privacy, confidence, copyright or other proprietary rights in favour of Aristocrat, its affiliates or third parties, is not lost because this email was sent to you by mistake. If you received this email by mistake you should: (i) not copy, disclose, distribute or otherwise use it, or its contents, without the consent of Aristocrat or the owner of the relevant rights; (ii) let us know of the mistake by reply email or by telephone (+61 2 9413 6300); and (iii) delete it from your system and destroy all copies. Any personal information contained in this email must be handled in accordance with applicable privacy laws. Electronic and internet communications can be interfered with or affected by viruses and other defects. As a result, such communications may not be successfully received or, if received, may cause interference with the integrity of receiving, processing or related systems (including hardware, software and data or information on, or using, that hardware or software). Aristocrat gives no assurances in relation to these matters. If you have any doubts about the veracity or integrity of any electronic communication we appear to have sent you, please call +61 2 9413 6300 for clarification. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] SOLVED: RE: Home LAN and video
Thanks to Oscar, Glen and Martin. vlan did the trick. All 100% OK now. Bill -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] Perl with Apache2 (ubuntu/Debian)
I am having a bugger of a time getting a perl script to execute under Apache2 on an Ubuntu box. When I access the file I just get the option to download it, it will not execute (permissions are set to execute by world at the moment). Endless googling and I haven't found a straight forward HOWTO. Anyone have any favourite HOWTOs? --- DETAILS error.log: [Wed Jul 20 13:34:30 2005] [notice] Apache/2.0.53 (Ubuntu) mod_perl/1.99_14 Perl/v5.8.4 mod_ssl/2.0.53 OpenSSL/0.9.7e configured -- resuming normal operations my virtual server defn: # Perl PerlModule ModPerl::Registry Alias /as2proc/ /var/www/HOST/htdocs/as2proc/ Location /as2proc SetHandler perl-script PerlResponseHandler ModPerl::Registry PerlOptions +ParseHeaders Options +ExecCGI +Includes /Location -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Pros Cons of Unix databases
On Tue, Jul 19, 2005 at 11:25:55AM +1000, Howard Lowndes wrote: I think you are misunderstanding me. I am seeking info about dbm, ldbm, bdb, etc. not the SQL type databases. sqlite will give you the best of both worlds. It's a single file, embeddable (in for instance php5), but sql, unlike bdb etc. Matt -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Perl with Apache2 (ubuntu/Debian)
Simon Wong wrote:
I am having a bugger of a time getting a perl script to execute under
Apache2 on an Ubuntu box.
When I access the file I just get the option to download it, it will not
execute (permissions are set to execute by world at the moment).
1. su to become the apache user and try to execute the script.
2. Are you using a minimal perl script to see if it works?
Maybe something like this:
#!/usr/bin/perl
use strict;
print qq{Content-type: text/html\r\n\r\n
html
bodyh1Test/h1This is a test/body
/html
};
3. Check that the access.log does show the access occuring.
my virtual server defn:
# Perl
PerlModule ModPerl::Registry
Alias /as2proc/ /var/www/HOST/htdocs/as2proc/
Location /as2proc
SetHandler perl-script
PerlResponseHandler ModPerl::Registry
PerlOptions +ParseHeaders
Options +ExecCGI +Includes
/Location
This is a setup for what I have on an Apache 1.31 setup.
Location /blah
AllowOverride All
SetHandler perl-script
PerlHandler Apache::Registry
PerlSendHeader On
Options +ExecCGI
/Location
4. Perhaps remove the Registry or other options that aren't needed for a
minimal script and see if it works.
Mike
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