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Alberto Varesio is out of the office.
by A.Varesio＠spaziosystem.com 28 May '08

28 May '08

I will be out of the office starting 05/28/2008 and will not return until 05/29/2008. prova

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simple load balancing/failover for OWA
by Ruslan Sivak 28 May '08

28 May '08

We are building an exchange cluster with two front end Outlook Web Access servers. We would like to at least have some sort of failover, and prefereably load balancing for them. The MS recommended way is to use NLB, but for various reasons that's not working with our set up. We are looking to set up a single linux server and use something like LVS to load balance/fail over the connections. Looking at LVS, it looks like it hasn't been updated in a while. Is it stable? Is it still the preferred solution? Since OWA has sessions, but no session replication, we would need something that can keep directing the same client to the same server (either by IP, or preferably by cookie). Can LVS handle this? I also saw that the latest version of Apache has some sort of load balancing support. Can it be used to set something like this up? We are looking for the simplest solution that won't require a lot of maintanence. We understand that having a single LVS box creates a single point of failure, and are willing to accept the risk for now to keep things simpler. Russ

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memorial day kernel panic
by sbeam 28 May '08

28 May '08

I have a simple Tyan server with RAID1 on a 3ware 7002 that has been running updated Centos 5.1 for almost 3 weeks with no problem, it runs low-traffic Apache/PHP/mySQL and vsftpd sites exclusively - last night it crashed. The console showed something about a process named 'php' and gave a process id with the panic message, but that's all I can remember. Hard-rebooted and all was well... Then about 55 minutes later I was logged in with ssh and it froze. Another fun holiday trip back to the datacenter. This time I brought a camera, but found a message totally different - this seems more like a ext3/disk problem? http://www.flickr.com/photos/sbeam/2525251590/sizes/l/ the logs contain nothing unusual. I have set up a script to do a vmstat/ps dump every 10 minutes. Anything else advised by this kernel dump or places to look? Thanks much- Sam

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USB modem on centos
by Jerry Geis 28 May '08

28 May '08

I am playing with a USR (us robotics) USB modem model 5637. in the past I used internal modems and had no issues. One this unit I plugged it in, dmesg says its recogized. I did "ln -s /dev/ttyACM0 /dev/ttyS4" this works. I then did "cu -l /dev/ttyS4" type "AT" and I get OK... looking good. When I "ATDT my number" I get a connection at 1200 baud (which I should) and funny characters... I thought looks like a parity thing. I then did "cu -e -l /dev/ttyS4" type "AT" and I get OK... Now when I do "ATDT my number" I get a connection at 1200 baud and I get readable characters. In the past internal PCI modems I never had to do anything special, just the cu -l /dev/ttyS4. I thought modem to modem handled all that speed/parity stuff and computer to modem just always worked given the correct baud rate. Does anyone know what the issue might be here. The reason I am asking is my program that talks to the modems (computer to modem) has always been setup for 8 data no parity and has always worked. When I use my program on the USB modem it is not working and I assumed from the parity issue above using "cu" to demonstrate. When I change my program to be 7 data bits and even parity it still did not work. Was wondering if anyone had any USB modem experience on centos and might know what is going on? Thanks, Jerry

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why there is no liblua5.1.so in /usr/lib?
by bqj123 28 May '08

28 May '08

hello all: I want to install ModSecurity v2.5.4 in my system. I do the following setup to install the lua tar -xzvf lua-5.1.3.tar.gz cd lua-5.1.3/src make linux cd .. make install The ModSecurity ask me to add "LoadFile /usr/lib/liblua5.1.so" to the http.conf,but there is no liblua5.1.so in /usr/lib. I have search it and i didn't find the solution. Can any one tell me why there is no liblua5.1.so in /usr/lib Thanks for any reply.

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clustered mail server?
by Rudi Ahlers 28 May '08

28 May '08

Hi all I'm looking for a working HOWTO / Tutorial / sample setup of setting up a clustered email server. I know I can setup a CentOS cluster with Heartbeat & drbd, but I'm not 100% convinced it will work for the email as well. Ideally, I'd like to use an open source groupware server, like say open exchange, php groupware, Scalix (free / community version), etc. So, if anyone can please point me in the right direction? I've already setup a heartbeat cluster, and use rsync to sync files for Samba, Apache & NFS, and also setup a Master-Master MySQL replication, but don't yet know how to setup the email server, -- Kind Regards Rudi Ahlers CEO, SoftDux Web: http://www.SoftDux.com Check out my technical blog, http://blog.softdux.com for Linux or other technical stuff, or visit http://www.WebHostingTalk.co.za for Web Hosting stuff

19 57

Fault tolerance with webservers
by gopinath 28 May '08

28 May '08

dear all i have a web server on centos 4.6. i have configured one more back up Webserver with the same configuration as the same on the primary web server Now how to configure this servers for fault tolerance. that is. if one server gets down the other should automatically become up. Please any one help me out how to configure the above. i am new to Linux ... Regards, Gopinath M Signal Networks Pvt. Ltd. Smile... it increases your face value!

6 5

Xen tools
by Ruslan Sivak 27 May '08

27 May '08

I have been playing around with Citrix XenServer Express. It seems pretty cool, and mostly meets my needs, except that the Express (Free) version only supports up to 4GB of RAM. I have 8GB on my machines. Since XenServer is based on Xen, I should be able to just install a base install of CentOS and use a third party management client to get all (most?) of the functionality of the XenServer without having to be limited to 4GB of RAM. Can someone recommend tools that I can use to manage the Xen hosts? I see there is Ganeti, but that seems to be linux only. I would prefer a windows or a web client, as I intend to have the actual Xen hosts be as stripped down installation as possible. As far as being able to utilize 8GB in CentOS do I need to install the x86_64 version, or is there some sort of AWE support? I remember reading that x86_64 version has some compatibility issues. Thanks in advance, Russ

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Re: [CentOS] Strange slapd behavior...
by Ramon Nieto 27 May '08

27 May '08

Hi Are you using nss_ldap on that server? have you modified /etc/nsswitch.conf? If that's the case try adding the following line to /etc/ldap.conf nss_initgroups_ignoreusers root,ldap Best. --- El mar 27-may-08, Stjepan Gros <stjepan.gros(a)gmail.com> escribió: De:: Stjepan Gros <stjepan.gros(a)gmail.com> Asunto: [CentOS] Strange slapd behavior... A: centos(a)centos.org Fecha: martes, 27 mayo, 2008, 10:56 am Hi all, I have problems on one CentOS 4.6 with slapd. Namely, after trying to start it (via /etc/init.d/ldap start) it waits for very long in configuration check. Interestingly, when I try to start it manually, but without "-u ldap" option it starts immediately. What puzzles me more is the use of NETLINK socket when started with -u option that doesn't appear in strace output without using the option. I did grep through the source of the openldap for NETLINK but nothing was found. Can someone shed some lite on what's happening? Thanks, Stjepan _______________________________________________ CentOS mailing list CentOS(a)centos.org http://lists.centos.org/mailman/listinfo/centos ____________________________________________________________________________________ Yahoo! Deportes Beta ¡No te pierdas lo último sobre el torneo clausura 2008! Entérate aquí http://deportes.yahoo.com

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Re: memorial day kernel panic {Scanned}
by Ross S. W. Walker 27 May '08

27 May '08

Scott Silva wrote: > on 5-27-2008 10:16 AM Ross S. W. Walker spake the following: > > sbeam wrote: > > > On Tuesday 27 May 2008 11:39, Scott Silva wrote: > > > > > > > > Running memtest for 24 hours should be enough to test the ram. > > > > A 3ware 7006 is a fairly old card. Does it have the latest bios available > > > > from 3ware? > > > > > > > > You could always eliminate the 3ware controller by installing a drive on > > > > whatever built in controller it has. > > > > > > this is a production server, so running an extended memtest not going to > > > happen. But I can swap it out and put it in a backup system to do the test. > > > It's beginning to look a lot like a RAM issue as I have now seen a couple > > > segfaults from programs that have always run fine. Every kernel panic message > > > is different (crashed again 1 hour ago). Fans and case temp are nominal. > > > > > > the 3ware card was just purchased last month, it has the latest firmware and > > > bios installed. > > > > > > the memory is from PQI - supposed to be an OK brand right? it has a lifetime > > > warranty... heh > > > > > > next steps... HA and fault-tolerant clustering, per the adjacent thread... > > > this is the cautionary tale come to life. > > > > It would be great if there were a simple machine that you could plug > > a bunch of dimms of varying types into and it will perform high-speed > > tests on them continuously and flag ones that show an error. > > > > Then you could test all memory modules thoroughly before putting them > > into production servers (or any server for that matter). > > That is why a good long burn in test is a worthwhile thing to > plan for. That is unless you need to rush a replacement > server out quickly. Yes, but even then, with say 16GB or 32GB of memory it happens that some errors just fall through the cracks. > I usually run memtest86 for 48 hours, and then run a burn in > test with some load. > > There are simple machines for testing memory, but they tend > to be very expensive and time consuming. Manufacturers can't > take the time to do thorough memory tests before they ship, > so they usually do some quick go-nogo tests and depend on > their warranty dept. to do the hard tests. > > I don't think it would pay for anyone to buy one of these > testers, unless you are a very large var like Dell or HP. It > is easier (and probably cheaper) to just send new ram out and > send the returns back to your supplier for them to check. I actually found a memory testing system for around $4K, yes it's about the cost of a well equiped server, but if it works well it should earn it's keep pretty quick. It's called RAMCHECK, I priced out the DDR/DDR2 unit, but there is add-ons for SODIMM, SDRAM, EDO, if you got it fully loaded I suspect it would be around $5K. Company's called Innovations http://www.memorytesters.com/ They're Government registered and CDW seems to resell it, so it isn't completely suspect. -Ross ______________________________________________________________________ This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution or copying of this e-mail, and any attachments thereto, is strictly prohibited. If you have received this e-mail in error, please immediately notify the sender and permanently delete the original and any copy or printout thereof.

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