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a cloud VM under CentOS
by Boris Epstein 05 Feb '12

05 Feb '12

Hello everyone, Does anyone know if it is possible to construct a cloud of sorts out of several CentOS machines so as to enable a VM (or several VM's) that would run on top of that cloud and have failover capability? Boris.

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CentOS 6.2 New Kernel Issues
by Jonathan Vomacka 05 Feb '12

05 Feb '12

CentOS 6.2 Community / Developers, Are there any known issues with the latest Kernel on CentOS 6.2? I performed a yum update and the kernel downloaded. When the system rebooted I started having intermittent latency issues when trying to perform certain commands on the system such as top or ls -ltr, etc. I was having extreme latency getting to root. I am unsure if there is a hardware compat issue but I found my server in kernel PANIC mode the next day and was unable to login entirely. Has this been reported before?

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Double Copies Double Copies
by Mark LaPierre 04 Feb '12

04 Feb '12

Hey Y'all, why am I getting double copies of every email on this list today when it wasn't happening yesterday? Isn't happening on any of my other email. -- _ °v° /(_)\ ^ ^ Mark LaPierre Registerd Linux user No #267004

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install detecting disk as sdb not sda
by Jerry Geis 04 Feb '12

04 Feb '12

I am trying to install 6.2 on a machine. I am using PXE as I have done so a number of times. My hard disk is being detected as sdb and not sda. My kickstart config is wanting it at sda. There are no other disks in the unit. It has and SD slot and an esata although BIOS does not appear to have a disable for either of those devices. Is there anyway to "force" the disk to sda ? or find out what its detecting at sda and disable that from the PXE boot line? Doing " dmesg | grep sda" does say SCSI removable disk. So how can I tell linux to NOT include that when installing? Thanks, jerry

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Re: [CentOS] network intermitent, not sure if virtualization issue
by Digimer 04 Feb '12

04 Feb '12

On 02/03/2012 03:55 PM, Bob Hoffman wrote: > On the virtual machine, which is having the issue, this is my eth0 > (I have been commenting out things to see if anything changes the issue.) Looks fine. > on the main machine which experiences no problems. > > eth0 and 1 onboard, eth 2 add on card, all are the same except > hwaddress, uuid, etc. Looks fine, assuming of course that the DEVICE and HWADDR are different. :) > (tried playing with bonding mode, but got nowhere there, again, the host > machine never has an issue) Are you bonding for performance or reliability? Bridge config looks fine, too. > not sure why vnet0 shows up in ifconfig, it is there and sometimes it is > not depending on boot.... Are you using KVM? I assume so. Regardless, the 'vnetX' interface is the link between the VM and the bridge. Think of it as your virtual network cable. As such, it exists when the VM exists, and is deleted when the VM migrates or is shut down. What does 'cat /proc/net/bonding/bond0' show on either node? -- Digimer E-Mail: digimer(a)alteeve.com Papers and Projects: https://alteeve.com

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upgrade centos 5 to 6
by fakessh ＠ 04 Feb '12

04 Feb '12

upgrade question is it possible to imagine during an upgrade from centos 5 to 6 to keep the named directory /etc and /var unchanged if an update as simple as possible. can this be -- http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xC2626742 gpg --keyserver pgp.mit.edu --recv-key C2626742 http://urlshort.eu fakessh @ http://gplus.to/sshfake http://gplus.to/sshswilting http://gplus.to/john.swilting

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Re: [CentOS] postfix - reject of incoming mail due to helo check??
by Stephen Harris 03 Feb '12

03 Feb '12

On Fri, Feb 03, 2012 at 11:47:06PM +0100, Reindl Harald wrote: > Am 03.02.2012 23:32, schrieb Stephen Harris: > > If you're telling me that my internal mail servers must talk to each > > other via the name pool-173-71-187-61.pitbpa.fios.verizon.net then... > > well, never mind. > > i am telling you that your network design is poor and yes if THIS is > your rDNS it has to be your HELO Fortunately, you're wrong. The real world doesn't work the way you think it should. Which is a relief to everyone else! -- rgds Stephen

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Re: [CentOS] postfix - reject of incoming mail due to helo check??
by Stephen Harris 03 Feb '12

03 Feb '12

On Fri, Feb 03, 2012 at 11:17:29PM +0100, Reindl Harald wrote: > Am 03.02.2012 22:58, schrieb Stephen Harris: > > If your mail server talks to machine with IP address 1.2.3.4 then should > > it say HELO with the 10 address name or the 91 address name? > > if you are not too stupid your internl view and external view of > dns-names is identical and there is no difference *boggle* What? Wow. No. Just no. That won't even work on a toy home network where your ISP sets the rDNS, it definitely won't work on a large corporate network. It only works in a trivial environment. If you're telling me that my internal mail servers must talk to each other via the name pool-173-71-187-61.pitbpa.fios.verizon.net then... well, never mind. -- rgds Stephen

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Re: [CentOS] postfix - reject of incoming mail due to helo check??
by Stephen Harris 03 Feb '12

03 Feb '12

On Fri, Feb 03, 2012 at 10:34:20PM +0100, Reindl Harald wrote: > > > Am 03.02.2012 20:58, schrieb Stephen Harris: > > On Fri, Feb 03, 2012 at 08:04:31PM +0100, Reindl Harald wrote: > >> does not change that it is a dmaned good idea this days > >> to make matching A/PTR/HELO and it is EASY to do this > > > > A & PTR, yes. HELO, no. It's not even possible to do HELO matching PTR > > when NAT gets in the way. > > WHAT has NAT to do with this? > > my mailserver has intern 10.0.0.x, external 91.118.73.x > my internal DNS has the PTR/A for the NAt address > external DNS have the PTR/A for the public idea > > what in the world let you think that NAT does change anything? If your mail server talks to machine with IP address 1.2.3.4 then should it say HELO with the 10 address name or the 91 address name? The mail server doesn't know what IP address will be presented to the remote machine, so it can't pick the correct name for the HELO. This is why I agree that A/PTR values should match, but there's no way for the HELO value to match. -- rgds Stephen

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Re: [CentOS] postfix - reject of incoming mail due to helo check??
by Stephen Harris 03 Feb '12

03 Feb '12

On Fri, Feb 03, 2012 at 08:04:31PM +0100, Reindl Harald wrote: > Am 03.02.2012 20:01, schrieb Stephen Harris: > > In this, Les is correct. The RFCs merely say the HELO needs to _a_ valid > > identifier for the host. Indeed this discussion was on this list back in > > July ("SPAM on the List") where I pointed out that RFC 5321 says > > i know the RFCs > > does not change that it is a dmaned good idea this days > to make matching A/PTR/HELO and it is EASY to do this A & PTR, yes. HELO, no. It's not even possible to do HELO matching PTR when NAT gets in the way. -- rgds Stephen

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