- WLUG - wlug.mailman3.com

REMINDER: WLUG meeting WED evening, 7:00 PM

by Andy Stewart

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 - -- Andy Stewart (KB1OIQ) Founder: Worcester Linux Users' Group Founder: Chelmsford Linux Meetup Group President: PART of Westford, MA (WB1GOF) -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iD8DBQFLxSwFOjiraCaOTOoRAgY9AJ48+m3FtDHzJFkYYXvZ+WDSOuxbSwCg4tOJ ZJq6U7xYepjyR10/dha1Jus= =kNxp -----END PGP SIGNATURE-----

April 14, 2010

Upcoming meeting: April 14th (Wednesday)

by Andy Stewart

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 HI Everybody, This is an early announcement about our upcoming WLUG meeting, which is next week on Wednesday, April 14th, 2010, at 7:00 PM. I have been the acting president of WLUG since I founded the group back in July 1997. Due to increasing pressures on my personal time, I think it is time for me to step aside and let another person be the president of WLUG. I definitely have enjoyed the privilege of being the group president, and I plan to continue attending the group meetings. I think that our next meeting should include a detailed discussion of the future of WLUG, and sometime soon, an election of at least a president, and probably a treasurer. I am happy to continue acting as president until such an election occurs. I don't know if we really need a vice president and or a secretary, but those topics should definitely be part of the discussion. I think the group has been very successful due to all of you who come to the meetings, give presentations, etc. This announcement, and the election of a new president, will definitely change the group. I see this is an opportunity for the group to grow in different ways. There is no doubt that the group will be different. Whether it becomes better or worse is really up to all of us. I look forward, as always, to seeing you at the meeting *next* week on Wednesday, April 14th. Later, Andy - -- Andy Stewart (KB1OIQ) Founder: Worcester Linux Users' Group Founder: Chelmsford Linux Meetup Group President: PART of Westford, MA (WB1GOF) -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iD8DBQFLuoNmOjiraCaOTOoRAun1AJ9Wz6jx4wvHKat9UUnOhrjcsIeZEgCglkUD x02mDM/AGIAGYPwAQ48qDUg= =iwnj -----END PGP SIGNATURE-----

April 6, 2010

Re: [Wlug] How to manipulate audio (ALSA) a lot with a HD audio card?

by Gregory Avedissian

You might be looking for something like jackaudio or maybe pulseaudio. I know that Jack lets you connect things any way you want. Not sure about pulse. http://jackaudio.org/ The extra jack on your computer is probably a line in, for external sources, such as your stereo. You should be able to record input from that in Audacity without doing anything special. Recording digital input is another story, and I don't know that story. Greg Tatsh wrote: > Stupid Intel decided to build-in DRM into the spec of these things. I have a > Conexant which has Nvidia codec to provide audio for the HDMI output (this > works fine except that in alsa settings I have to force a default output > device, 3). > > What I'd like to do is be able to record from the stereo mixer, which I have > none in alsamixer. So how do I go about creating one? I've tried a few > different configs I found on-line but nothing seemed to work for me. > > WIth this capability of course I could record audio from my computer in say, > Audacity, or I could even broadcast audio through Skype. And the best part > would be if I could broadcast audio through Skype AND use my headset at the > same time (mixing the 2 into one channel input). I have 3 mic inputs > apparently (one of them is webcam, another is the jack, and I don't know what > the 3rd one is). > > Image of KMix: http://bitpic.net/image/kmix-nvidia-hd-audio-codec > > So far I know it's something I can do with ALSA settings where I can tell ALSA > to redirect audio and 'copy' whatever is going on on any input channel > (overriding the jack of course). No luck there yet. > > Any help appreciated > Thanks

April 2, 2010

Two Senior IT positions open at TripAdvisor in Newton (IT and Operations)

by Ryan Pugatch

Hi all, We have a couple of tech positions open at TripAdvisor. The first is for a "Principal Technical Operations Engineer" which is on our operations team, handling our livesite environment. The second, "IT Lead", is on our internal IT team. Below are the job postings. We're definitely looking for people with several years experience. If you are interested, please email me your resume. I am also glad to answer any questions. - Ryan (Systems Administrator @ TripAdvisor) ---------------------------------------------------------------------------- Principal Technical Operations Engineer Hundreds of servers. Thousands of requests per second. Millions of users. Two admins (you could be number 3)! We are looking for a senior hands-on network (mostly Cisco) and systems (mostly Linux) administrator. You will have several years of prior experience in the operation of one or more of the following: High traffic web application OR Software as a service OR Internet/Network Service Provider TripAdvisor is the top site for travel advice and reviews on the Internet. It is very profitable. It's also a fun place to work where "speed wins" is the operating principle. We move fast. We are flexible and we take risks. An open mind and ideas are always welcome. Dogmatism and inflexibility not so much. You will play a lead role in the design and operation of the network, server, and datacenter infrastructure beneath TripAdvisor's applications. The environment currently spans 3 datacenters, and that is likely to increase. You will work closely with the software engineering team to support product changes and enhance their performance, scalability, reliability, and security. We are small team. You will be expected to work on a project or task from end to end with a comfort level running projects and implementing the details. One day you might be working with our ISPs to transition from static routing to BGP, and the next day you are racking and cabling switches. This morning you are kicking off a load balancer replacement project, and in the afternoon you are upgrading firewall firmware after you determine that we are exposed to a potential security vulnerability. This week you are putting together a comprehensive network monitoring system, and next week you are running tcpdump with a DBA to try and diagnose why database replication is "slow". You will have a thorough knowledge of enterprise networking including Cisco switching, routing, and security as well as TCP/IP internals. You will also preferably have a strong Linux or Unix background. ---------------------------------------------------------------------------- IT Lead TripAdvisor is looking for an IT generalist who will provide leadership and mentoring to a team of 4 supporting the IT needs of roughly 350 employees worldwide. This role is part hands-on sysadmin and part team lead with the potential to grow into a team management role. TripAdvisor is the top site for travel advice and reviews on the Internet. It is very profitable. It's also a fun place to work where "speed wins" is the operating principle. We move fast. We are flexible and we take risks. An open mind and ideas are always welcome. Dogmatism and inflexibility not so much. We are not your typical Windows / Active Directory / Exchange shop. Desktops: 60% Windows 40% OSX. Our email/collaboration system is Zimbra running on Linux. Our phone system is Asterisk running on Linux. Instead of Active Directory, we use OpenLDAP. Our file/print servers run Samba. We tend to prefer open solutions that we can take off the shelf and adapt to our needs, but we are not wedded to a particular OS or vendor. To be successful in this role you will: Possess excellent interpersonal skills, patience, and a genuine desire to help people with their technology challenges Have strong troubleshooting skills and a diagnostic intuition Enjoy and excel at mentoring other talented team members to reach their full potential Be a self-starter. If you don't know how to do something you consider it a challenge to try to figure it out for yourself You will have demonstrated experience with: Linux systems administration Windows systems administration Samba OpenLDAP Postfix Server virtualization Scripting (perl, python, bash...) Duties and Responsibilities include: Operation of corporate networked applications and infrastructure (Zimbra, OpenLDAP, Samba, Asterisk) Overseeing backups of roughly 20+TB of data weekly Ensuring the security of TripAdvisor's corporate systems Procuring and deploying server hardware Tier 2/3 Helpdesk support Working with the Director of IT to develop IT strategy

April 2, 2010

Re: [Wlug] the website is in need of some love

by Tim Keller

Yeah, I agree the site needs an overhaul. However, what does the website need to minimally do? * - Meeting Information * - Mailing List sign up * - Past Meeting info * - IRC channel info We've kicked around the idea of a wiki, which I'd be totally cool with and I'd help maintain. My personal opinion is that between the IRC channel, Dr. Google and the mailing list, a forum is overkill. On Thu, Apr 1, 2010 at 3:02 PM, Chuck Anderson <cra(a)wpi.edu> wrote: > On Thu, Apr 01, 2010 at 09:20:44AM -0400, Jeff Moyer wrote: > > I'm not sure who maintains it, but it's in a very sad state at the > > moment. > > Congratulations! You've just been volunteered to enhance it! :-) > > But hey, at least it validates now. > > Seriously though, if anyone would like to help, feel free to email me. > There was a time when I was playing with Moin for a wiki site but that > fell by the wayside. I really need to rebuild the system that the web > server is running on, so I could deploy something new/better if there > was someone who would commit to helping maintain it. I just don't > have the time to do anything fancy, learn new web frameworks, etc. > > Alternatively, people could submit some designs, code, and content > that uses plain HTML/CSS and I could maintain that manually. > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug > -- I am leery of the allegiances of any politician who refers to their constituents as "consumers".

April 2, 2010

Re: [Wlug] How to manipulate audio (ALSA) a lot with a HD audio card?

by E Johnson

I can't answer these questions, but have a question about one idea in here. > WIth this capability of course I could record audio from my computer in say, Audacity, or I could even broadcast audio through Skype. I don't think broadcasting audio (would this be music??) through Skype would create the greatest audio, since Skype is so sensitive to packet loss & all. Each (small) packet has to be received at its destination in perfect order, and on-time. If one or more hops that your signal is taking is running slow (as it gets in Worcester in the evenings), then packets get lost and have to be resubmitted. Check your technical details next time you're in a skype convo, then do a traceroute on the IP of your skype contact --you can see this happening. If this is the case when you're sending recorded audio through it, you would be likely to suffer from chopped-up sound, which happens in skype a lot. So if you broadcast through skype and there's a lot of latency, or if your router is swamped because there's a lot of traffic inside of your network, then you would end up making square waves in the skype out of what probably started out as a perfectly nice audio signal. You could try to counteract that (I guess) by running some kind of QOS in your router, but even that itself slows the router down a little bit, as every packet has to be evaluated according to your QOS table. Just wondering. Liz J On 1 April 2010 10:14, Tatsh <ddrtist(a)gmail.com> wrote: > Stupid Intel decided to build-in DRM into the spec of these things. I have > a > Conexant which has Nvidia codec to provide audio for the HDMI output (this > works fine except that in alsa settings I have to force a default output > device, 3). > > What I'd like to do is be able to record from the stereo mixer, which I > have > none in alsamixer. So how do I go about creating one? I've tried a few > different configs I found on-line but nothing seemed to work for me. > > WIth this capability of course I could record audio from my computer in > say, > Audacity, or I could even broadcast audio through Skype. And the best part > would be if I could broadcast audio through Skype AND use my headset at the > same time (mixing the 2 into one channel input). I have 3 mic inputs > apparently (one of them is webcam, another is the jack, and I don't know > what > the 3rd one is). > > Image of KMix: http://bitpic.net/image/kmix-nvidia-hd-audio-codec > > So far I know it's something I can do with ALSA settings where I can tell > ALSA > to redirect audio and 'copy' whatever is going on on any input channel > (overriding the jack of course). No luck there yet. > > Any help appreciated > Thanks > -- > Tatsh > www.bitpic.net > www.tatsh.net > ddrtist(a)gmail.com > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug >

April 2, 2010

Re: [Wlug] Use Drupal On The Web Site - Wlug Digest, Vol 78, Issue 1

by Steven Greenberg

I am all in favor of Jeff's suggestion. I first tested Drupal on my personal web site (http://www.ssgreenberg.name/Drupal/Drupal/) I then convinced my Square Dance Club to let me work with the Webmaster to convert that site to Drupal. We have had nothing but raves from the readers since we converted. http://www.hayloftsteppers.org/ When judging the site, remember, we are (or were) engineers, not artists. /Steve > ------------------------------------------------------------------------ > > Subject: > Re: [Wlug] the website is in need of some love > From: > Tatsh <ddrtist(a)gmail.com> > Date: > Thu, 1 Apr 2010 10:05:30 -0400 > To: > wlug(a)mail.wlug.org > > To: > wlug(a)mail.wlug.org > > > Would be cool to do it over in Drupal. > > NOT JOOMLA (should be called 'piece of crap please give up already!')! > > All you need is a blog post system (built-in) to write about events, and add > custom fields like time if you want, etc etc. From a design stand point, there > is no reason to use images for the textual links, especially obviously > compressed JPEGs. > > Late > > Jeff Moyer wrote: >> I'm not sure who maintains it, but it's in a very sad state at the >> moment. >> >> Cheers, >> Jeff -- Steven Greenberg Email: steve(a)ssgreenberg.name 251 Holland Rd. Phone: (774)241-0095 Fiskdale, Massachusetts 01518-1231 Web: http://www.ssgreenberg.name Other Email: s.greenberg(a)ieee.org ssg(a)alum.mit.edu

April 1, 2010

Re: [Wlug] the website is in need of some love

by Chuck Anderson

On Thu, Apr 01, 2010 at 09:20:44AM -0400, Jeff Moyer wrote: > I'm not sure who maintains it, but it's in a very sad state at the > moment. Congratulations! You've just been volunteered to enhance it! :-) But hey, at least it validates now. Seriously though, if anyone would like to help, feel free to email me. There was a time when I was playing with Moin for a wiki site but that fell by the wayside. I really need to rebuild the system that the web server is running on, so I could deploy something new/better if there was someone who would commit to helping maintain it. I just don't have the time to do anything fancy, learn new web frameworks, etc. Alternatively, people could submit some designs, code, and content that uses plain HTML/CSS and I could maintain that manually.

April 1, 2010

How to manipulate audio (ALSA) a lot with a HD audio card?

by Tatsh

Stupid Intel decided to build-in DRM into the spec of these things. I have a Conexant which has Nvidia codec to provide audio for the HDMI output (this works fine except that in alsa settings I have to force a default output device, 3). What I'd like to do is be able to record from the stereo mixer, which I have none in alsamixer. So how do I go about creating one? I've tried a few different configs I found on-line but nothing seemed to work for me. WIth this capability of course I could record audio from my computer in say, Audacity, or I could even broadcast audio through Skype. And the best part would be if I could broadcast audio through Skype AND use my headset at the same time (mixing the 2 into one channel input). I have 3 mic inputs apparently (one of them is webcam, another is the jack, and I don't know what the 3rd one is). Image of KMix: http://bitpic.net/image/kmix-nvidia-hd-audio-codec So far I know it's something I can do with ALSA settings where I can tell ALSA to redirect audio and 'copy' whatever is going on on any input channel (overriding the jack of course). No luck there yet. Any help appreciated Thanks -- Tatsh www.bitpic.net www.tatsh.net ddrtist(a)gmail.com

April 1, 2010

Re: [Wlug] the website is in need of some love

by Tatsh

Would be cool to do it over in Drupal. NOT JOOMLA (should be called 'piece of crap please give up already!')! All you need is a blog post system (built-in) to write about events, and add custom fields like time if you want, etc etc. From a design stand point, there is no reason to use images for the textual links, especially obviously compressed JPEGs. Late Jeff Moyer wrote: > I'm not sure who maintains it, but it's in a very sad state at the > moment. > > Cheers, > Jeff > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug > -- Tatsh www.tatsh.net ddrtist(a)gmail.com

April 1, 2010

the website is in need of some love

by Jeff Moyer

I'm not sure who maintains it, but it's in a very sad state at the moment. Cheers, Jeff

April 1, 2010

Re: [Wlug] interesting article on RAID

by John Stoffel

Theo> Yeah, it's complicated by the fact that a lot of RAID systems Theo> will consider any I/O error to mean the entire device is bad. This is why Netapp has moved to their double-parity raid sets. It's a help, but not perfect. I'm going to read the article in a few and then comment in particular. Theo> ZFS does a particularly good job here, I've seen single raidz2 Theo> sets able to recover from having 4 simultaneously failing disks. Now that's interesting. How was performance during this issue? Theo> I've had other vendor's arrays start failing disks while Theo> reconstructing from a single failure. Thankfully it was only 1 Theo> additional failure on a 2 parity set. Still PITA. I once had a double disk failure in a Netapp. Ouch! This was before their double parity stuff was widely deployed. One disk died due to head problems, the other died due to the controller board on the disk dying. I managed to swap the good board from the bad hardware disk onto the good hardware, bad board disk, re-insert it and have the system come back up and rebuild. Big sigh of relief there for sure! Another thing I like about alot of newer raid implementations (including Linux RAID, assuming you use it) is the consistency checks or scrubbing that you can run, to hopefully catch errors before they become problems. Reading the disk(s) and checking blocks for consistency, and even re-writing them to make sure the data is good. John

March 12, 2010

Re: [Wlug] interesting article on RAID

by Theo Van Dinter

Yeah, it's complicated by the fact that a lot of RAID systems will consider any I/O error to mean the entire device is bad. ZFS does a particularly good job here, I've seen single raidz2 sets able to recover from having 4 simultaneously failing disks. I've had other vendor's arrays start failing disks while reconstructing from a single failure. Thankfully it was only 1 additional failure on a 2 parity set. Still PITA. On Thu, Mar 11, 2010 at 8:09 PM, Chuck Anderson <cra(a)wpi.edu> wrote: > Triple-Parity RAID and Beyond > by Adam Leventhal | December 17, 2009 > > http://queue.acm.org/detail.cfm?id=1670144 > > As hard-drive capacities continue to outpace their throughput, the > time has come for a new level of RAID.

March 12, 2010

interesting article on RAID

by Chuck Anderson

Triple-Parity RAID and Beyond by Adam Leventhal | December 17, 2009 http://queue.acm.org/detail.cfm?id=1670144 As hard-drive capacities continue to outpace their throughput, the time has come for a new level of RAID. -- - Chuck (372 Days until IPv4 depletion: http://ipv4depletion.com/)

March 12, 2010

Meeting: BtrFS: Now (Thurs March 11 7pm)

by Chuck Anderson

Frank is giving a talk on BtrFS right now. It seems the website wasn't updated (but is now). -- - Chuck (372 Days until IPv4 depletion: http://ipv4depletion.com/) On Mon, Feb 22, 2010 at 06:18:44AM -0500, Frank Sweetser wrote: > I've noticed that not too many people have putting in meeting topic requests, > so I thought that if anyone's interested I'd volunteer to throw together some > slides on BtrFS. > > For those of you who haven't heard of it, BtrFS is the next generation linux > filesystem. Though still in heavy development, it was included in the > mainstream kernel last year. It promises to scale to filesystems well beyond > what any of the current offerings can handle (including ext4), as well as > offering far greater flexibility and better data security for data admins. > > If you have anything else that you'd like to hear about, either instead of or > in addition to BtrFS, chime in, and hopefully someone else on the list will be > able to make it happen! > > -- > Frank Sweetser fs at wpi.edu | For every problem, there is a solution that > WPI Senior Network Engineer | is simple, elegant, and wrong. - HL Mencken > GPG fingerprint = 6174 1257 129E 0D21 D8D4 E8A3 8E39 29E3 E2E8 8CEC

March 12, 2010

Re: [Wlug] Meeting topics

by Jeff Moyer

"John Stoffel" <john(a)stoffel.org> writes: >>>>>> "Jeff" == Jeff Moyer <jmoyer(a)redhat.com> writes: > Jeff> I've seen many claims that SSDs are more reliable than > Jeff> traditional HDDs, but I haven't seen data to back up those > Jeff> claims. > > Some of the arguements I've read on SSD reliability are quite > interesting. If you do the math on how much data you need to write to > destroy an SSD with proper (note!) wear levelling, it's really quite > high. But I think the real key is to write data to them in blocks of > 512 bytes as much as possible, and to not write smaller amounts if at > all possible. Did you mean to say 512KB? You can't write smaller than the exported block size (which will be either 512 bytes or 4k). Perhaps what you meant to say was that you should try to issue writes that are aligned on and multiples of the erase block size. > Jeff> My main concern is that SSDs are still young, so they haven't > Jeff> had much soak time. Whether or not the flash is reliable is > Jeff> only a small part of the battle. Buggy firmware is a much more > Jeff> likely problem at this stage in the game. No single point of > Jeff> failure is a good design point when dealing with your data. ;-) > > I think this is a key issue, the firmware and controllers, not the > flash chips themselves. > > Jeff> I remain cautiously optimistic (though I've already bricked one > Jeff> drive). > > Details? During TRIM testing, we managed to get an OCZ Vertex to spew I/O errors, and then finally fail to be recognized by the BIOS upon reboot. Note that this isn't a normal workload (the drive is being pounded on) and TRIM is still very new. So, I am not saying that the drives are not reliable in general. I simply don't know. Cheers, Jeff

March 2, 2010

Re: [Wlug] Meeting topics

by John Stoffel

>>>>> "Jeff" == Jeff Moyer <jmoyer(a)redhat.com> writes: Jeff> Chuck Anderson <cra(a)WPI.EDU> writes: >> On Mon, Mar 01, 2010 at 04:46:44PM -0500, Jim Dibb wrote: >>> On Mon, Mar 1, 2010 at 4:21 PM, Chuck Anderson <cra(a)wpi.edu> wrote: >>>> I'm interested. I was considering using SSDs for my boot drive. Is >>>> RAID protection necessary/advisable using SSDs? >>> >>> SSDs have much higher reliability than HDD. >>> Mirroring is the only RAID level that does not impose a write penalty. >>> Mirroring SSDs is expensive >>> >>> Based on these 3 points, I'd say a backup is a much better solution than >>> RAID, unless you want to (R)AID-0 them into a stripe for even more insane >>> performance. >>> >>> But then again, you didn't state how important your uptime of your system >>> is. Sorry for leaving that bit out.... >> >> Uptime/availability isn't that important, but backups are since RAID >> *is* my backup (plus rsync to other RAIDed systems for the most >> important data). With traditional disk drives, it hasn't been too >> expensive to slap a 2nd system drive in for RAID 1/mirroring. SSDs >> are much more expensive, so if as you say they are more reliable, >> perhaps I can forgo the expense of doing RAID on them. Jeff> I've seen many claims that SSDs are more reliable than Jeff> traditional HDDs, but I haven't seen data to back up those Jeff> claims. Some of the arguements I've read on SSD reliability are quite interesting. If you do the math on how much data you need to write to destroy an SSD with proper (note!) wear levelling, it's really quite high. But I think the real key is to write data to them in blocks of 512 bytes as much as possible, and to not write smaller amounts if at all possible. Jeff> My main concern is that SSDs are still young, so they haven't Jeff> had much soak time. Whether or not the flash is reliable is Jeff> only a small part of the battle. Buggy firmware is a much more Jeff> likely problem at this stage in the game. No single point of Jeff> failure is a good design point when dealing with your data. ;-) I think this is a key issue, the firmware and controllers, not the flash chips themselves. Jeff> I remain cautiously optimistic (though I've already bricked one Jeff> drive). Details? John

March 2, 2010

Re: [Wlug] Meeting topics

by Jeff Moyer

Chuck Anderson <cra(a)WPI.EDU> writes: > On Mon, Mar 01, 2010 at 04:46:44PM -0500, Jim Dibb wrote: >> On Mon, Mar 1, 2010 at 4:21 PM, Chuck Anderson <cra(a)wpi.edu> wrote: >>> I'm interested. I was considering using SSDs for my boot drive. Is >>> RAID protection necessary/advisable using SSDs? >> >> SSDs have much higher reliability than HDD. >> Mirroring is the only RAID level that does not impose a write penalty. >> Mirroring SSDs is expensive >> >> Based on these 3 points, I'd say a backup is a much better solution than >> RAID, unless you want to (R)AID-0 them into a stripe for even more insane >> performance. >> >> But then again, you didn't state how important your uptime of your system >> is. Sorry for leaving that bit out.... > > Uptime/availability isn't that important, but backups are since RAID > *is* my backup (plus rsync to other RAIDed systems for the most > important data). With traditional disk drives, it hasn't been too > expensive to slap a 2nd system drive in for RAID 1/mirroring. SSDs > are much more expensive, so if as you say they are more reliable, > perhaps I can forgo the expense of doing RAID on them. I've seen many claims that SSDs are more reliable than traditional HDDs, but I haven't seen data to back up those claims. My main concern is that SSDs are still young, so they haven't had much soak time. Whether or not the flash is reliable is only a small part of the battle. Buggy firmware is a much more likely problem at this stage in the game. No single point of failure is a good design point when dealing with your data. ;-) I remain cautiously optimistic (though I've already bricked one drive). Cheers, Jeff

March 1, 2010

vmbuilder - Ubuntu Lucid?

by John Stoffel

Hi, Anyone else using vmbuilder with Ubuntu's 10.x Lucid Lynx (Alpha3, I know) and cursing the change in options that just happened recently? I've been playing around building VMs (based on Karmic) and tossing them away since it was so quick. Now that I've upgrade to a newer version of Lucid, it's all busted. Sigh... This would be a good talk too, about building and using VMs. Here's the script I whipped up to help automate things, which is now busted. Sigh... I realize I need to just look in the docs, but they a) suck and b) aren't easily found. Nor is any list of changes in the options listed nicely either. Grrr!!!! THanks, John #!/bin/sh # My own script for building and starting VMs more easily, based on # the instructions given at: # # http://www.howtoforge.com/virtualization-with-kvm-on-ubuntu-9.10 # # Version 0.1 - 12/29/2009 # if [ $# -ne 3 ]; then echo "Usage: $0 hostname ip username" echo " IP is last octet of the 192.168.1/24 subnet" echo exit fi euid=`id -u` if [ $euid -ne 0 ]; then echo "Error! Script must run with root privs. Try sudo $0 ...." echo exit fi hostname=$1 ip=$2 username=$3 vmbase="/var/vm" subnet="192.168.1" suite="karmic" bridge="br0" mem=256 mirror="http://192.168.1.3:9999/ubuntu" # LVM stuff volgroup="virtmachs" #--------------------------------------------------------------------- # Make the directory where we store the VM config #--------------------------------------------------------------------- if [ -d ${vmbase}/${hostname} ]; then /bin/rm -rf ${vmbase}/${hostname} fi mkdir -p ${vmbase}/${hostname} cd ${vmbase}/${hostname} #--------------------------------------------------------------------- # Copy over the template, but use the fixed one instead in vm0 #--------------------------------------------------------------------- mkdir -p ${vmbase}/${hostname}/mytemplates/libvirt cp ${vmbase}/vm0/mytemplates/libvirt/* ${vmbase}/${hostname}/mytemplates/libvirt/ #--------------------------------------------------------------------- # Setup partitions file #--------------------------------------------------------------------- cat >vmbuilder.partition <<EOF root 8000 swap 2000 /var 10000 EOF #--------------------------------------------------------------------- # Setup the boot.sh file #--------------------------------------------------------------------- cat >boot.sh <<EOF # This script will run the first time the virtual machine boots # It is run as root. # Expire the user account /usr/bin/passwd -e ${username} # Set the root password /usr/sbin/usermod -p '$1$MbDcN3NU$ndC6TvQ1.a1VG0jbeW3hD.' root # Install openssh-server apt-get update apt-get install -qqy --force-yes openssh-server nfs-client nfs-common mkdir /local /staging /home echo "jfsnew:/home /home nfs soft,sec=sys,vers=3,tcp,rsize=32768,wsize=32768,nolock 0 0" >> /etc/fstab echo "jfsnew:/local /local nfs soft,sec=sys,vers=3,tcp,rsize=32768,wsize=32768,nolock 0 0" >> /etc/fstab echo "jfsnew:/staging /staging nfs soft,sec=sys,vers=3,tcp,rsize=32768,wsize=32768,nolock 0 0" >> /etc/fstab mount /home mount /local mount /staging echo "America/New_York" > /etc/timezone cp /usr/share/zoneinfo/America/New_York /etc/localtime EOF #--------------------------------------------------------------------- # Create LVM volume for VM #--------------------------------------------------------------------- if [ ! -e /dev/${volgroup}/${hostname} ] then lvcreate -L20G -n ${hostname} ${volgroup} else echo echo "Skipping lvcreate, Logical Volume ${hostname} already exists." echo fi #--------------------------------------------------------------------- # Run vmbuilder #--------------------------------------------------------------------- echo vmbuilder kvm ubuntu --suite=${suite} --flavour=virtual --arch=amd64 --mirror=${mirror} -o --libvirt=qemu:///system --tmpfs=- --ip="${subnet}.${ip}" --part=vmbuilder.partition --templates=mytemplates --user=${username} --name=${username} --pass=${username} --addpkg=vim-nox --addpkg=unattended-upgrades --addpkg=acpid --raw=/dev/virtmachs/${hostname} --firstboot=boot.sh --mem=${mem} --hostname=${hostname} --bridge=${bridge} vmbuilder kvm ubuntu --suite=${suite} --flavour=virtual --arch=amd64 --mirror=${mirror} -o --libvirt=qemu:///system --tmpfs=- --ip="${subnet}.${ip}" --gateway="${subnet}.254" --part=vmbuilder.partition --templates=mytemplates --user=${username} --name=${username} --pass=${username} --addpkg=vim-nox --addpkg=unattended-upgrades --addpkg=acpid --raw=/dev/virtmachs/${hostname} --firstboot=boot.sh --mem=${mem} --hostname=${hostname} --bridge=${bridge} #--------------------------------------------------------------------- # Startup the VM #--------------------------------------------------------------------- if [ -e /etc/libvirt/qemu/${hostname}.xml ] then virsh define /etc/libvirt/qemu/${hostname}.xml virsh start ${hostname} else echo "Error! VM ${hostname} not created properly." echo exit fi

March 1, 2010

Re: [Wlug] Meeting topics

by Chuck Anderson

On Mon, Mar 01, 2010 at 04:46:44PM -0500, Jim Dibb wrote: > On Mon, Mar 1, 2010 at 4:21 PM, Chuck Anderson <cra(a)wpi.edu> wrote: >> I'm interested. I was considering using SSDs for my boot drive. Is >> RAID protection necessary/advisable using SSDs? > > SSDs have much higher reliability than HDD. > Mirroring is the only RAID level that does not impose a write penalty. > Mirroring SSDs is expensive > > Based on these 3 points, I'd say a backup is a much better solution than > RAID, unless you want to (R)AID-0 them into a stripe for even more insane > performance. > > But then again, you didn't state how important your uptime of your system > is. Sorry for leaving that bit out.... Uptime/availability isn't that important, but backups are since RAID *is* my backup (plus rsync to other RAIDed systems for the most important data). With traditional disk drives, it hasn't been too expensive to slap a 2nd system drive in for RAID 1/mirroring. SSDs are much more expensive, so if as you say they are more reliable, perhaps I can forgo the expense of doing RAID on them.

March 1, 2010

Re: [Wlug] Meeting topics

by Jeff Moyer

Chuck Anderson <cra(a)WPI.EDU> writes: > On Sun, Feb 28, 2010 at 06:26:31PM -0500, Jeff Moyer wrote: >> If anyone is interested in a talk on SSDs, chime in. I can present my >> experiences with these devices. I've evaluated the performance of >> several vendors' products, ranging from the poor to the exemplary. I >> can talk about the modifications made in the block layer to accommodate >> for these devices, and the current implementation of the block discard >> support (which maps to ATA TRIM, which is important for device lognevity >> and performance) and how that is wired up to file systems such as ext4. > > I'm interested. I was considering using SSDs for my boot drive. Is > RAID protection necessary/advisable using SSDs? The answer is, as always, it depends. I'll cover this in more depth when I give the talk, but any RAID algorithm that needs to initialize every block of the device is going to hurt performance on SSDs. There is some question about the durability/reliability of the drives, and some of those concerns are valid, others aren't. If you are diligent about backups, or if the disk just holds the OS, I wouldn't worry too much about RAID. HTH, Jeff

March 1, 2010

Re: [Wlug] Meeting topics

by Jim Dibb

But then again, you didn't state how important your uptime of your system is. Sorry for leaving that bit out.... On Mon, Mar 1, 2010 at 4:45 PM, Jim Dibb <jimdibb(a)gmail.com> wrote: > > > On Mon, Mar 1, 2010 at 4:21 PM, Chuck Anderson <cra(a)wpi.edu> wrote: > >> >> >> I'm interested. I was considering using SSDs for my boot drive. Is >> RAID protection necessary/advisable using SSDs? >> _______________________________________________ >> Wlug mailing list >> Wlug(a)mail.wlug.org >> http://mail.wlug.org/mailman/listinfo/wlug >> > > SSDs have much higher reliability than HDD. > Mirroring is the only RAID level that does not impose a write penalty. > Mirroring SSDs is expensive > > Based on these 3 points, I'd say a backup is a much better solution than > RAID, unless you want to (R)AID-0 them into a stripe for even more insane > performance. > >

March 1, 2010

Re: [Wlug] Meeting topics

by Jim Dibb

On Mon, Mar 1, 2010 at 4:21 PM, Chuck Anderson <cra(a)wpi.edu> wrote: > > > I'm interested. I was considering using SSDs for my boot drive. Is > RAID protection necessary/advisable using SSDs? > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug > SSDs have much higher reliability than HDD. Mirroring is the only RAID level that does not impose a write penalty. Mirroring SSDs is expensive Based on these 3 points, I'd say a backup is a much better solution than RAID, unless you want to (R)AID-0 them into a stripe for even more insane performance.

March 1, 2010

Re: [Wlug] Meeting topics

by Patrick Dignan

On 03/01/2010 04:21 PM, Chuck Anderson wrote: > On Sun, Feb 28, 2010 at 06:26:31PM -0500, Jeff Moyer wrote: > >> If anyone is interested in a talk on SSDs, chime in. I can present my >> experiences with these devices. I've evaluated the performance of >> several vendors' products, ranging from the poor to the exemplary. I >> can talk about the modifications made in the block layer to accommodate >> for these devices, and the current implementation of the block discard >> support (which maps to ATA TRIM, which is important for device lognevity >> and performance) and how that is wired up to file systems such as ext4. >> > I'm interested. I was considering using SSDs for my boot drive. Is > RAID protection necessary/advisable using SSDs? > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug > I second Chuck here.

March 1, 2010

Re: [Wlug] Meeting topics

by Chuck Anderson

On Sun, Feb 28, 2010 at 06:26:31PM -0500, Jeff Moyer wrote: > If anyone is interested in a talk on SSDs, chime in. I can present my > experiences with these devices. I've evaluated the performance of > several vendors' products, ranging from the poor to the exemplary. I > can talk about the modifications made in the block layer to accommodate > for these devices, and the current implementation of the block discard > support (which maps to ATA TRIM, which is important for device lognevity > and performance) and how that is wired up to file systems such as ext4. I'm interested. I was considering using SSDs for my boot drive. Is RAID protection necessary/advisable using SSDs?

March 1, 2010