- WLUG - wlug.mailman3.com

Re: Wlug Digest, Vol 23, Issue 4

by joel d

Hi, Based on one of our post-meeting pizza discussions last night I thought I would send an e-mail (something I do so rarely). Here is a site that has a good selection of WIFI gear (APs/amps/antennas). I have never ordered from them but they appear to have a good selection of radio gear. http://www.fab-corp.com/ A few ideas to remember: 1) A stronger omni directional antenna (greater db numbers) will improve both your transmit and receive and both are important for range for WIFI. 2) Directional antennas must be aimed at the other radio. You get more gain, but they are usually not the solution if you want to wander your house/deck/yard with the laptop. 3) Amplifiers have downsides; 1) another device to power 2) another device to fail later 3) a good one runs around $200 with both transmit amp and receive pre-amp. 4) Antennas are rated in decibels (db). Most antennas on access points are round 3db - 5db. In terms of signal strength an increase of 3db is a doubling of effective power (Ex 3db to 9db is roughtly 400% stronger). 5) The weakest link in WIFI is usually the card and particularly the internal antenna in the laptop on the far end. 6) You do not succeed unless both devices can both "transmit" and "receive" the other radio. 7) Selection of a feed cable for an external antenna is VERY important. At 2+ghz frequencies a long cable (>1 foot) or a poor quality cable will loose everything you are trying to gain with a better "numbers" antenna. >From a local computer AND radio geek, Joel Desrochers

Sept. 9, 2005

Re: [Wlug] Reminder: Upcoming Meeting

by Andy Stewart

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Andy Stewart wrote: > > HI Everybody, AAAhhhhhhhh!! I blew it....the website it correct, my email is bogus. The meeting is indeed Thursday, Sept. 8th !! I can't believe I did that....my apologies. Andy - -- Andy Stewart, Founder Worcester Linux Users' Group Worcester, MA, USA http://www.wlug.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.5 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFDH4edHl0iXDssISsRAuo1AJ4/DBQn+ieS1A0jvitSV0sOhmSepQCfWiMu ReeRrYPs2EjQG6Nsa04HmbE= =+qj+ -----END PGP SIGNATURE-----

Sept. 8, 2005

Reminder: Upcoming Meeting

by Andy Stewart

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 HI Everybody, We have a WLUG meeting scheduled for Thursday, Sept. 15 at 7:00 PM in the Access Grid room at WPI. I'm not sure of the topic, but if nothing better turns up, I'll start babbling about my most recent USB experience (which started unpleasantly but ultimately had a happy ending), and we can segue from there into whatever topic people wish to discuss. Bring your Linux problems and try to stump the audience. :-) I'll bring my iAudio G3 MP3/Ogg player since a couple of people said they wanted to see it. I had hoped to have it at the last meeting but it wasn't shipped to me in time. Naturally, we'll go out for pizza after the meeting. We can discuss the insanity of looting televisions during a flood crisis, the possibility of adding anti-DRM language to GPL v3, and whatever else we find interesting. See ya then! Andy - -- Andy Stewart, Founder Worcester Linux Users' Group Worcester, MA, USA http://www.wlug.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.5 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFDHmZ4Hl0iXDssISsRAka9AJ9HkAi7ZYGZfg7JokWZFeuzWbGK/wCfeJ9D yEQ7aHTYE9/JB6zT4fJUl0I= =8ain -----END PGP SIGNATURE-----

Sept. 7, 2005

Re: [Wlug] SuSE dual [core] frustration.... - update

by Adam Keck

Hi All, I am having much better luck with the SuSE kernel-smp-2.6.11.4-21.8 kernel. The dual core machine boots normally (i.e. without maxcpus=1) and /proc/cpuinfo shows the four cores. Unfortunately, the SuSE's (9.3) particular iteration of the forcedeth module seems to be having trouble with the networking bits of the nforce4 SLI chipset. Rather than dipping into the SuSE kernel-of-the-day development builds, I think I am going to drop in an Intel NIC in order to move forward. I will send an update when we put the machine through its paces. -Adam p.s. I just found a shrink-wrapped Maxell Mammoth cleaning tape and an upwrapped unused Compaq DLT IV tape in a moving bin. I don't need them anymore. I will let the DLT IV go for 15.00 and the cleaning tape go for 5.00. Email me off list if you are interested. I can bring them to the Sept. meeting. On Jul 27, 2005, at 7:06 PM, Andy Stewart wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > > HI Adam et al, > > As you may recall, I had a lot of trouble with SuSE and lockups on my > dual Opteron system until I upgraded to a stock 2.6.12 kernel (not the > SuSE supplied kernel). I haven't tried any kernel version beyond that > because what I have actually works and is reliable. I'd be curious to > know what kernel version you use and what result you have with it. > > Later, > > Andy > > - -- > Andy Stewart, Founder > Worcester Linux Users' Group > Worcester, MA, USA > http://www.wlug.org > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.2.5 (GNU/Linux) > Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org > > iD8DBQFC6BOEHl0iXDssISsRAtOZAJ0VXJh3ItUMnhGWz52z0nDz3NFsTACeOLgL > yxWAPWkJnE43XGnpv2WDI0k= > =mBD8 > -----END PGP SIGNATURE----- > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug >

Sept. 5, 2005

Linux Job opportunity

by Andy Stewart

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 If interested, please send me email, and I'll send you the contact information. The job is located in Massachusetts near the intersection of Rt 3 and Rt 128. === LINUX Technical Lead: Job Functions: Serve as a technical lead responsible for bringup, test and development of LINUX operating systems on server platforms. Responsibilities of this role are to: * Define and execute on bring-up, test and development strategy for LINUX * Interact with internal and external teams to ensure that LINUX requirements are met * Identify technical risks within the project and plans to manage them * Root cause bugs and implement corrective actions * Provide input to management on project milestones and schedule * Give periodic technical status updates to management and engineering teams. Skills: * Experience with industry standard LINUX operating systems * Experience with X86 architecture * Project delivery experience * Strong leadership skills * Ability to effectively communicate with wide variety of functional teams (system hardware, system software, QA, operating systems, manufacturing test, field engineering) * Effective in lab bring-up environment * Ability to root cause hardware/software issues in the lab * Strong hardware and software skills 10+ years experience === - -- Andy Stewart, Founder Worcester Linux Users' Group Worcester, MA, USA http://www.wlug.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.5 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFDGE/RHl0iXDssISsRAms0AJ94Ror2w0Vsr/Hh2yC2N1/Xcq15qACfco9s +N5grzVwMGmiUX6g4m4ZW1M= =4x/C -----END PGP SIGNATURE-----

Sept. 2, 2005

Re: [Wlug] Speaking of interesting meetings...

by Andy Stewart

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Bill Smith wrote: > Le Wed, 31 Aug 2005 20:56:17 -0400 > >>This month, I've been debugging USB problems on my server, and I >>think I may have made some progress on USB 1.x, but not on USB 2.x. >>I'm not sure if this is a meeting topic - howto get stuff to work on >>USB and how to debug it if it does not. >> >>Your thoughts? > > Does this involve fixing problems with USB devices that have worked > with Linux in the past, or it more along the lines of hacking devices > that don't have working drivers? I've been playing around with my MP3 player and trying to make it work on my server. It works fine on my laptop. The MP3 player is a usb_storage device (iAudio G3). I didn't hack any drivers, nor have I ever. I had thought that perhaps I could start a discussion of this topic, where folks would kick in their 2 cents worth, and collectively we'd come away with more knowledge about using Linux and USB. Its just a thought - I'm not sure anybody is interested, or perhaps this is old hat to most of you. Since we have an upcoming meeting on Sept. 8th, I'm looking for ideas, and thought this might be one. Later, Andy - -- Andy Stewart, Founder Worcester Linux Users' Group Worcester, MA, USA http://www.wlug.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.5 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFDF5yhHl0iXDssISsRAmVtAJ0do8qhIUpbb0/ls4xts5ejAYfFiACeMMg/ 9oAVbxvGPOJ1Xp/VJtAMJk0= =VFBz -----END PGP SIGNATURE-----

Sept. 2, 2005

Re: [Wlug] Speaking of interesting meetings...

by Bill Smith

Le Wed, 31 Aug 2005 20:56:17 -0400 > This month, I've been debugging USB problems on my server, and I > think I may have made some progress on USB 1.x, but not on USB 2.x. > I'm not sure if this is a meeting topic - howto get stuff to work on > USB and how to debug it if it does not. > > Your thoughts? Does this involve fixing problems with USB devices that have worked with Linux in the past, or it more along the lines of hacking devices that don't have working drivers? -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- William Smith wsmith-at-chezsmith-dot-com Fall River, MA http://www.chezsmith.com The minute you say you can't, you won't... ...and then you fail. * TAG! v3.1a *

Sept. 1, 2005

Re: [Wlug] Re: Wlug Digest, Vol 22, Issue 18

by John Stoffel

Carlton> I've done software RAID (RAID0 and RAID5) for a long time and Carlton> never had to use an initrd image. Just have a 100 MB boot Carlton> partition on one drive, and set root=/dev/md0 in grub. For me, the whole idea of booting of RAID is so that I can lose either disk, and not really notice. Currently, I don't have that. And since my main test system is also my main work system at home, I'm loathe to screw with it much. *grin* Carlton> This is with two 60GB WD HD's and one 80 GB (which has the Carlton> bootable 100 MB partition). If you RAID it all, well, guess Carlton> you need an initrd (please correct me if I'm wrong). As far as I know, yes you do need an initrd (or initramfs now?) to make it work properly. Carlton> As far as RAID1 and RAID5, isn't RAID5 strictly better, if Carlton> you have the HD's? I mean, just lose 1/3 of the storage for Carlton> total mirroring and you have to lose 2 HD's to lose your Carlton> data. Why would someone choose RAID1 over RAID5 (just Carlton> curious)? I did have a RAID5 system set up, but decided to Carlton> change it over to RAID0 and use an external Maxtor drive for Carlton> backup (just simple rsync). RAID0 = stripping RAID1 = mirroring RAID5 = parity RAID5 suffers on write performance when compared to RAID1, since if you write a small chunk of data, RAID5 may have to actually READ/COMPUTE PARITY/WRITE to all the drives. With RAID1, it's a simple parallel write to each drive. No READ overhead. RAID5 can generally just lose 1 disk from the set without losing data. RAID1 can lose 1/2 the mirror without losing data. How you implement your RAID1 setup across more than two disks is an issue. I choose RAID1 over RAID5 because I only had space for two drives, and I only had an HPT302 with dual channels, so I put one disk on each channel for maximum peformance. If I had more money and a 3ware controller, I probably would have gone for RAID5 on my data, since it has a size/cost advantage over RAID1. I would NEVER go for RAID0 for my data, too much potential for data loss. Even with backups. Carlton> Personally, I feel if you compile a couple of kernels it Carlton> really becomes old hat, I mean, once you know how to do it Carlton> it's no big deal. Same with RAID systems. But that would be Carlton> an interesting meeting, nonetheless. Exactly, it would be an interesting meeting to show people how easy it is to implement, and hopefully how robust it is as well, esp if you lose your primary harddisk. Can you boot cleanly from the secondary one? You have updated the MBR on that disk, right? Carlton> I've never had a problem and found I needed initrd to get Carlton> something to work. What are the benefits of using it? >From what I know, the advantage/requirement of using an initrd is that you can boot off of a funky device, since you first boot into a small OS image with all the tools you need to setup and switch to your main filesystems. In my case, I've got a pair of 9gb SCSI disks, and I currently boot off one. My plan has always been to mirror the two disks so that if I lost one, I could still boot. My data is all on a pair of 120gb IDE drives, which are mirrored, and which have saved me from ugly restores, because I noticed that one disk had dropped out and I was able to just re-mirror without any major impact. John

Sept. 1, 2005

Speaking of interesting meetings...

by Andy Stewart

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ...what do you all propose for a topic for the Sept. 8 meeting? More importantly, does anybody want to do a presentation or lead the discussion? This month, I've been debugging USB problems on my server, and I think I may have made some progress on USB 1.x, but not on USB 2.x. I'm not sure if this is a meeting topic - howto get stuff to work on USB and how to debug it if it does not. Your thoughts? Thanks! Andy - -- Andy Stewart, Founder Worcester Linux Users' Group Worcester, MA, USA http://www.wlug.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.5 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFDFlGxHl0iXDssISsRAneXAJ0Rkqhwc9rkJ60lsWDUKA0UQdNGKQCeKwCG Ed27RqXttkP9STLCkoo2OQ0= =4xsk -----END PGP SIGNATURE-----

Sept. 1, 2005

Re: Wlug Digest, Vol 22, Issue 18

by Carlton C. Stedman II

Re: Bootable RAID system > I keep waffling back and forth between RAID1 (mirroring) and RAID5. > And I keep waffling between booting from RAID or not. Part of the > problem is that to boot off raid, you need to build a intrd image, and > since I do a bunch of kernel compiles and reboots all the time (say > once a week or so...) I've been a bit leary of all that. I've done software RAID (RAID0 and RAID5) for a long time and never had to use an initrd image. Just have a 100 MB boot partition on one drive, and set root=/dev/md0 in grub. This is with two 60GB WD HD's and one 80 GB (which has the bootable 100 MB partition). If you RAID it all, well, guess you need an initrd (please correct me if I'm wrong). As far as RAID1 and RAID5, isn't RAID5 strictly better, if you have the HD's? I mean, just lose 1/3 of the storage for total mirroring and you have to lose 2 HD's to lose your data. Why would someone choose RAID1 over RAID5 (just curious)? I did have a RAID5 system set up, but decided to change it over to RAID0 and use an external Maxtor drive for backup (just simple rsync). > Now that would be a good meeting some evening, talking about and > showing how to setup a bootable RAID system for the OS and how to > upgrade your kernel easily and automatically. Personally, I feel if you compile a couple of kernels it really becomes old hat, I mean, once you know how to do it it's no big deal. Same with RAID systems. But that would be an interesting meeting, nonetheless. > Let me rephrase your reasoning: You don't want to use an initrd because > you aren't familiar with the process. Just because you do a lot of kernel > builds/reboots (and your definition of a lot is my definition of very few, > here), that is no reason not to use an initrd. I've never had a problem and found I needed initrd to get something to work. What are the benefits of using it? - Carlton

Sept. 1, 2005