Re: [SLUG] Wireless card.
On 21/02/07 14:56, john gibbons wrote: Is there a suitable wireless card for a desktop that is sure to be OK for all or most flavours of Linux? I've had plenty of success with Atheros chipset based PCI and PCMCIA wireless NICs. In particular, the Netgear WG311T has worked well for me. All Atheros stuff is supported under linux with Madwifi http://madwifi.org/wiki/Compatibility for other supported cards. Good luck, Adam. -- 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] Oddball memory usage?
On 22/02/07, Peter Hardy [EMAIL PROTECTED] wrote: On Thu, 2007-02-22 at 16:24 +1100, Zhasper wrote: On 22/02/07, Peter Hardy [EMAIL PROTECTED] wrote: I'm a little puzzled by this: total used free sharedbuffers cached Mem:50050844816352 188732 0 1566443165540 -/+ buffers/cache: 14941683510916 Swap: 10526161052616 0 Is this sort of usage normal? Filling a gigabyte of swap space while just under 1.5GB of memory is going towards buffers seems odd to me. And vmstat reports no usage of this swap space over a 15 minute period. What sort of utilities are around to analyse swap space? I'd like to get an idea of exactly what's using all of that memory. You're running Linux, right? Aye. It's a 2.4 kernel dating from somewhere before swappiness became tuneable. This can be really great on a system with not much ram where large apps that you haven't used in a while (eg, OOo) will get swapped out when they're not being used, to make lots of space to cache all the pr0^H^H^Himages of your grandmother's birthday party that you're scanning through agressively.. In my rush to be as detailed as possible, I completely forgot to mention what the machine in question is actually doing. Well, it's a web server for a single (fairly high-traffic) domain. Apart from apache and the web application software, there's nothing running on it apart from the usual collection of processes that are essential to a well behave unix system. init, crond, syslogd. I'd be looking at top (or other tools which give similar output), particular at the RES and VIRT columns. VIRT shows the total amount of memory used by a process; RES shows the amount of that that's located in RAM (the rest has been swapped out) Given what you said, my two-seconds-thought-while-sitting-in-armchair hunch is that Apache (or more likely, come CGI you're using) does have some kind of memory leak, and is slowly gobbling ram - but the kernel is smart enough to see that the pages, although claimed, are unused, so it's swapping them. I would also guess that your site either has a lot of static content which, rather than being read from disk a lot, the kernel is caching in ram. You mentioned web application software, so it could be files used by that too - config files, databases, etc. Check your RRDTool graphs to see if swap/memory usage has been growing over time - particular that really handy graph that differentiates between buffers/cache/actually-used-by-applications ram usage, so that you can see if, perhaps, the amount of used and buffers/cache have remained about the same, while swap usage has been creeping up I think I'm agreeing with everyone else - the kernel usually does a pretty good job of handling the balance between buffers/cache and application ram. If you're seeing performance issues, check sar/iostat/vmstat/similar to see if there's a lot of swapping happening; if that's the case, you might have a problem. If there's a lot of disk IO that's not swapping, you might have the opposite problem - not enough swapped out to cache all the frequently used files. Either way, extra ram should help a lot, and extra swap may help out as well - allow more files to be cached, at the expense of infrequent extreme performance issues as those files get dumped from ram as the system frantically swaps pages back in... The other possibility is that you actually do have a memory leak, which is going to be a lot of fun. As always, monitoring is your friend... Looking at the output of free tells you what the system is like now, looking at historical trends tells you how it got there - whether this is a normal condition, something that has gradually arisen, or something that abruptly occured overnight... This is easily the biggest system I've found myself responsible for, and the way the memory's been allocated doesn't line up with anything else I've seen before. Just curious as to how and why it's being used like this. -- There is nothing more worthy of contempt than a man who quotes himself - Zhasper, 2004 -- 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] Oddball memory usage?
Peter Hardy [EMAIL PROTECTED] writes: On Thu, 2007-02-22 at 16:24 +1100, Howard Lowndes wrote: It's recommended that your swap space should be 2x your RAM. In your case it's .2x Has anybody seriously made such a recommendation this millenium? early 2.4 kernels, linus, alan, rik, etc, said at least double the swap was needed, especially with big uptimes. It changed somewhere in 2.4 where it was no longer needed, but I think people like red hat took a while before they trusted and used the new code. -- 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] Oddball memory usage?
Peter Hardy wrote: It's recommended that your swap space should be 2x your RAM. In your case it's .2x Has anybody seriously made such a recommendation this millenium? It was only briefly a good recommendation for Windows 95, which I recall ran slower when physical ram + swap went over 64Mb. If you had 64Mb, win 95 would run fastest with no swap space at all, yet the popular wisdom of best swap size = 2x physical just wouldn't die. There is no substitute for empirical testing. Adelle. -- 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] IBM calculate that 4Gb RAM is optimal for Vista
Where is Howard trying to bash microsoft? Stop being over sensitive. And what does this have to do with Linux? I really hate people attempting to bash Microsoft their products on OSS lists. IMHO It really makes everyone look like zealots. Cheers, Scott [EMAIL PROTECTED] wrote on 21/02/2007 05:01:19 PM: http://www.computerworld.com/action/article.do? command=viewArticleBasicarticleId=9011523 -- Howard. LANNet Computing Associates - Your Linux people http:// lannetlinux.com When you want a computer system that works, just choose Linux; When you want a computer system that works, just, choose Microsoft. -- Flatter government, not fatter government; abolish the Australian states. -- 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 -- 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] Oddball memory usage?
I think you'll find the formula dated to the time when most people said I really need my total memory address space to be n megabytes, but I can only possibly afford n/3 megabytes of RAM, so I have to just make do with 2n/3 being on a relatively slow hard disk. This certainly applied when I maxed out my first PC, a 486/33 with 8MB RAM back in 1993 [1]. Just being able to run 16MB of RAM+swap using SLS [2] was heaven. I could have allocated more swap but I could only afford a 210MB hard disk (and I reckon adding any more swap would have been pretty much been counter-productive.). Regards, Martin [1] For those of you into Linux nostalgia, I actually posted a question on one of the NNTP newsgroups on how to share my Linux swap space with Windows 3.1. (Google groups has the memory of an elephant - http://groups.google.com.au/group/comp.os.linux.help/browse_thread/thread/7f6d399f350a6eee/710993141162f89b?lnk=stq=martin.m.c.visser+linuxrnum=1#710993141162f89b ) [2] http://en.wikipedia.org/wiki/Softlanding_Linux_System On 2/22/07, Howard Lowndes [EMAIL PROTECTED] wrote: Michael Chesterton wrote: Peter Hardy [EMAIL PROTECTED] writes: On Thu, 2007-02-22 at 16:24 +1100, Howard Lowndes wrote: It's recommended that your swap space should be 2x your RAM. In your case it's .2x Has anybody seriously made such a recommendation this millenium? early 2.4 kernels, linus, alan, rik, etc, said at least double the swap was needed, especially with big uptimes. It changed somewhere in 2.4 where it was no longer needed, but I think people like red hat took a while before they trusted and used the new code. A default FC install still uses the 2x formula so I guess there must still be some relevance. -- Howard. LANNet Computing Associates - Your Linux people http://lannetlinux.com When you want a computer system that works, just choose Linux; When you want a computer system that works, just, choose Microsoft. -- Flatter government, not fatter government; abolish the Australian states. -- 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] Oddball memory usage?
On Thu, Feb 22, 2007 at 09:57:48PM +1100, Howard Lowndes wrote: Michael Chesterton wrote: Peter Hardy [EMAIL PROTECTED] writes: On Thu, 2007-02-22 at 16:24 +1100, Howard Lowndes wrote: It's recommended that your swap space should be 2x your RAM. In your case it's .2x Has anybody seriously made such a recommendation this millenium? early 2.4 kernels, linus, alan, rik, etc, said at least double the swap was needed, especially with big uptimes. It changed somewhere in 2.4 where it was no longer needed, but I think people like red hat took a while before they trusted and used the new code. A default FC install still uses the 2x formula so I guess there must still be some relevance. interestingly rhel4 (don't use fc) and from what I have seen of rhel5, they still use 2G swap partitions. what we are probably seeing is if it ain't broken don't fix/modify it. -- Howard. LANNet Computing Associates - Your Linux people http://lannetlinux.com When you want a computer system that works, just choose Linux; When you want a computer system that works, just, choose Microsoft. -- Flatter government, not fatter government; abolish the Australian states. -- 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] Oddball memory usage?
On 23/02/07, Martin Visser [EMAIL PROTECTED] wrote: I think you'll find the formula dated to the time when most people said I really need my total memory address space to be n megabytes, but I can only possibly afford n/3 megabytes of RAM, so I have to just make do with 2n/3 being on a relatively slow hard disk. This certainly applied when I maxed out my first PC, a 486/33 with 8MB RAM back in 1993 [1]. Just being able to run 16MB of RAM+swap I second that theory, only my experience was with BSD 4.2 on VAX machines - there it was exactly that way - you wanted lots of memory so the multiple users running physics simulations for weeks and months won't max it out but you were limited in amount of RAM you could afford or the system could handle, so you allocated swap on your disks. These days, just having to handle too many pages in the swap space could slow the system down (remember - every swap page requires the system to keep some meta data about it in memory and maybe on disk as well, looking for it through the linked lists and such). Also - if you system is so heavy on memory usage that it uses so much swap then it's going to be dog slow anyway and you better find another solution ( e.g. add RAM, have another server, optimize the programs running on it etc). --Amos -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] RAID Performance Oddness
Hi all, I have a question for any hardware experts out there: I'm currently scratching my head over an unexpected performance issue with a relative monster of a new machine compared to it's older, supposed to be superseded counterpart. Brief outline: Server A: 2 x 3Ghz Xeon (with hyperthreading shows as 4 CPUs) 2GB Ram 900GB RAID5 array comprised of 8x146GB 7500rpm disks on 2 spindles with a stripe size of 64k Server B: 4 x Dual Core 2.66Ghz Xeon (with HT shows as 16 CPUs) 3GB Ram 900GB RAID1+0 comprised of 6x300GB 10k rpm disks on 1 spindle with a stripe size of 128k Running write tests on both boxes and comparing sequential versus random writes shows some very unusual results that I'm having trouble interpreting - the test program creates a 1GB file, then writes to it again in 8k chunks, running each test twice to attempt to counter any issues with the state of the controller cache, so the second result should be a more realistic, or 'better' number: Server A: Fri Feb 23 03:00:01 EST 2007 sequentialWrite: 28.96 seconds sequentialWrite: 28.88 seconds randomWrite: 659.32 seconds randomWrite: 701.60 seconds Server B: Fri Feb 23 03:00:01 EST 2007 sequentialWrite: 52.76 seconds sequentialWrite: 41.32 seconds randomWrite: 81.39 seconds randomWrite: 82.20 seconds What I can't explain here is why a sequential write on the new box would take roughly 1.5 to 2 times as long as on the old box, yet the random write is around 8 to 8.5 times faster. Has anyone seen anything like this in the past and would care to hit me with a cluestick about how I might fix it? Is it possible that a combination of the stripe size and the single spindle on the new box could be slowing it down to this extent, or is there something else I am missing? TIA for any sage counsel, Craig -- 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] RAID Performance Oddness
Craig Dibble wrote: Hi all, I have a question for any hardware experts out there: I'm currently scratching my head over an unexpected performance issue with a relative monster of a new machine compared to it's older, supposed to be superseded counterpart. By the way - as far as I have been able to ascertain all other things are equal. Both boxes are using the same HP Smart Array 6402/128 controller and all other settings are equivalent - such as the cache/Accelerator Ratio settings. Also, if it matters - the block buffer cache is disabled in the small test program (which I didn't write). Craig -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] appliance - run single application
my google-fu is letting me down. i want run a single application on a machine, appliance like. was looking for a howto for ubuntu or debian but i'm obviously using the wrong search terms. any pointers? cheers marty -- M. Cullen I suffered from chronic hypochondria for years, eventually went to a naturopath, and was cured with a course of broad-spectrum placebos. [1] [1] - http://www.smh.com.au/articles/2003/12/08/1070732142498.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] appliance - run single application
Martin Barry wrote: my google-fu is letting me down. i want run a single application on a machine, appliance like. was looking for a howto for ubuntu or debian but i'm obviously using the wrong search terms. Not sure I understand what you're asking, but do you by any chance mean kiosk mode? A quick search* on that reveals plenty of links. Craig * I won't say 'a quick google' as I don't use it ;-) -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] Backup System - Any recommendations
Hi all, Can anyone recommend a backup solution that can be run centrally from a linux box and can also backup windows boxes on a LAN Apart from performing basic incremental data backups it will also need to be able to perform disk imaging over the wire (e.g disk images of windows boxes to be stored on the linux server to prevent me from having to reinstall XP and every other application known to man when disks fail) Compression is also a must have. Thanks again for your thoughts and suggestions! =) -- Regards, Trent -- 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] IBM calculate that 4Gb RAM is optimal for Vista
Voytek Eymont wrote: On Thu, February 22, 2007 12:46 pm, Jeff Waugh wrote: This leads me to ask about the equivalent for most Linux desktop setups. What is the sweet spot for RAM in a typical, say, Ubuntu desktop box? The point at which diminishing returns from improved functionality intersects with the increase in cost. 128-256MB if you just want to run the desktop (not wildly helpful to anyone). 512MB if you want to do some stuff as well (say, Firefox or OpenOffice.org). 1GB if you want to feel fairly pacey while doing some stuff (disk cache). not unlike XP, I'd guess Yep, that's pretty much the sweet spot for XP as well. Adam K -- 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] Oddball memory usage?
* On Thu, Feb 22, 2007 at 04:16:04PM +1100, Peter Hardy wrote: I'm a little puzzled by this: total used free sharedbuffers cached Mem:50050844816352 188732 0 1566443165540 -/+ buffers/cache: 14941683510916 Swap: 10526161052616 0 Is this sort of usage normal? Filling a gigabyte of swap space while just under 1.5GB of memory is going towards buffers seems odd to me. And vmstat reports no usage of this swap space over a 15 minute period. What sort of utilities are around to analyse swap space? I'd like to get an idea of exactly what's using all of that memory. correct me if I'm wrong vmstat is your friend. A figure consistently 0 for the so column (swap out) often indicates problems. My understanding is the memory manager in 2.6 will use a lot of swap on purpose. /correct me if I'm wrong eg $ vmstat 5 5 procs ---memory-- ---swap-- -io --system-- cpu r b swpd free buff cache si sobibo incs us sy id wa 0 0 65580 12984 155944 30252000 5 83 2 11 1 86 2 ... IBM do a good book on Linux Performance Tuning, which explains this well. -- Sonia Hamilton. GPG key A8B77238. -- 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] Backup System - Any recommendations
* On Fri, Feb 23, 2007 at 12:11:51PM +1100, Trent Murray wrote: Can anyone recommend a backup solution that can be run centrally from a linux box and can also backup windows boxes on a LAN Apart from performing basic incremental data backups it will also need to be able to perform disk imaging over the wire (e.g disk images of windows boxes to be stored on the linux server to prevent me from having to reinstall XP and every other application known to man when disks fail) Compression is also a must have. Bacula offers all these features. But requires a bit of RTFM'ing to get working, and sometimes can make you pull your hair out with unfathomable problems. I used to backup about 8 mixed machines at once, including some virtual servers hosted overseas. -- Sonia Hamilton. GPG key A8B77238. -- 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] Oddball memory usage?
Hey hey. On Fri, 2007-02-23 at 14:09 +1100, Sonia Hamilton wrote: correct me if I'm wrong vmstat is your friend. A figure consistently 0 for the so column (swap out) often indicates problems. My understanding is the memory manager in 2.6 will use a lot of swap on purpose. /correct me if I'm wrong That's the way I understand it as well. Ran vmstat over a 15 minute period yesterday that showed no activity at all either in or out of swap. I've been meaning to run it over a longer period today, but with one thing and another I've spent about three minutes actually in front of a computer today. IBM do a good book on Linux Performance Tuning, which explains this well. Oh, cool. I'll have to add it to my reading list. 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
Re: [SLUG] Backup System - Any recommendations
Trent , As a suggestion ! Rsync can perform some life saving stuff. cheers =MK= On Fri, 2007-02-23 at 12:11 +1100, Trent Murray wrote: Hi all, Can anyone recommend a backup solution that can be run centrally from a linux box and can also backup windows boxes on a LAN Apart from performing basic incremental data backups it will also need to be able to perform disk imaging over the wire (e.g disk images of windows boxes to be stored on the linux server to prevent me from having to reinstall XP and every other application known to man when disks fail) Compression is also a must have. Thanks again for your thoughts and suggestions! =) -- Regards, Trent -- Best Regards The Team at ABD Computers ABD Computer Installations Get A Better Deal ! Phone: 0408 867 967 Web: http://www.abdcomputers.net Email: [EMAIL PROTECTED] ABD Computer Installations E-mail and E-mail Server is Virus and Spyware Free. We request recipients of this E-mail to place us in the white-list of friendly E-mailers. -This privilege was achieved because we use Linux. -- 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] Backup System - Any recommendations
On Fri, Feb 23, 2007 at 12:11:51PM +1100, Trent Murray wrote: Hi all, Can anyone recommend a backup solution that can be run centrally from a linux box and can also backup windows boxes on a LAN Apart from performing basic incremental data backups it will also need to be able to perform disk imaging over the wire (e.g disk images of windows boxes to be stored on the linux server to prevent me from having to reinstall XP and every other application known to man when disks fail) Compression is also a must have. Thanks again for your thoughts and suggestions! =) have a look at mondo rescue -- Regards, Trent -- 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] Oddball memory usage?
On 23/02/07, Peter Hardy [EMAIL PROTECTED] wrote: IBM do a good book on Linux Performance Tuning, which explains this well. Oh, cool. I'll have to add it to my reading list. Thanks. I was looking for a link to include in a to read list when I found the following review: http://www.linuxjournal.com/article/8516 Cheers, --Amos -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
