Re: [Dovecot] Update on Issues
I reimaged my server, and it now has this kernel version: Linux server.paracastworld.net 2.6.27.15 So does this one behave itself? Peace, Gene
Re: [Dovecot] unkillable imap process(es) with high CPU-usage
It was likely compiled by the host/DC then, so it would not be a good idea to change it. Peace, Gene On Feb 15, 2009, at 2:19 PM, Timo Sirainen wrote: On Sun, 2009-02-15 at 13:42 -0700, Gene Steinberg wrote: On Feb 15, 2009, at 1:16 PM, Timo Sirainen wrote: 2.6.27.9 is buggy. I'm pretty sure upgrading the kernel will fix your problem. The yum upgrade function doesn't produce any updates. Your kernel version looks like it's self-compiled instead of from CentOS, so yum won't help you.
Re: [Dovecot] unkillable imap process(es) with high CPU-usage
On Feb 15, 2009, at 1:16 PM, Timo Sirainen wrote: 2.6.27.9 is buggy. I'm pretty sure upgrading the kernel will fix your problem. The yum upgrade function doesn't produce any updates. Peace, Gene
Re: [Dovecot] unkillable imap process(es) with high CPU-usage
On Feb 15, 2009, at 1:16 PM, Timo Sirainen wrote: 2.6.27.9 is buggy. I'm pretty sure upgrading the kernel will fix your problem. Would this be a simple yum upgrade to deliver? I don't want to cause worse difficulties. Peace, Gene
Re: [Dovecot] unkillable imap process(es) with high CPU-usage
On Feb 15, 2009, at 12:53 PM, Seth Mattinen wrote: Or it's I/O locked on the filesystem i.e. NFS server went away or something else. What state ate the un-killable processes in? (Z, D, S, etc.) ~Seth I'd have to switch back to Dovecot in order to test for this, and arrange to have someone with far more expertise than I possess to continue monitoring the server to catch this when it happens. cPanel support can't be expected to devote that much attention to preventive medicine. My admin could do it, I suppose, though I'm only one of his smaller clients, so I wouldn't expect it either. As I said, I'm inclined to want to try this again for testing, if someone would work with me on the initial setup, switching to a later version of Dovecot than the one that cPanel operates with (if it'll still integrate with cPanel -- is that possible?). Peace, GEne
Re: [Dovecot] unkillable imap process(es) with high CPU-usage
On Feb 15, 2009, at 12:43 PM, Timo Sirainen wrote: On Sun, 2009-02-15 at 12:10 -0700, Gene Steinberg wrote: This is sounding similar to the problem I have with my setup: 1. High CPU usage. 2. Can't kill IMAP. kill -9 doesn't work for imap processes? You didn't mention this before. I'm using CentOS 5.2 64-bit version with the latest cPanel. So what am I missing, other than the problem nobody else is having is clearly something they ARE having? If you can't kill -9 a process, it means the kernel is buggy. At least 2.6.27 was buggy and it was fixed in 2.6.27.10. Some of this is above my pay grade (so forgive the imprecision), but I did try to restart IMAP in cPanel with no success, assuming I catch it before the load makes it impossible to do anything. Yes, I have been able to kill processes by the standard ID number. I did that with rsync the other day when changing the backup parameters. Here's the kernel info on my box: Linux server.paracastworld.net 2.6.27.9rootserver-20081216a #1 SMP Tue Dec 16 02:29:13 EST 2008 x86_64 So that's a buggy kernel? Or is the 2.6.27.9 version better than 2.6.27 in this regard? Peace, Gene
Re: [Dovecot] unkillable imap process(es) with high CPU-usage
On Feb 14, 2009, at 9:57 AM, agent59624285 wrote: I have this EXACT same problem after upgrading to SuSE 11.1, which uses this exact kernel version!! After reading this, I was excited to think that if I killed the nfsserver daemon (which I had running for no good reason), that it would sort my problem Sure enough, my computer - which up to now had been going unresponsive every 24 hours - was running fine for 72 hours and then BOOM... it happened again. Just wanted to let people know that it seems that at the minute, the dovecot that ships with SuSE and the kernel they are using in 11.1 exhibit this problem. Gino This is sounding similar to the problem I have with my setup: 1. High CPU usage. 2. Can't kill IMAP. 3. Server becomes unresponsive. I'm using CentOS 5.2 64-bit version with the latest cPanel. So what am I missing, other than the problem nobody else is having is clearly something they ARE having? Peace, Gene
Re: [Dovecot] Strange Dovecot Issue with 64-bit AMD Processor
I'm at a disadvantage here. I'm more of the end user than admin, but I cope. But if someone wanted to assist me in maybe trying this again -- perhaps with the latest stable version -- I'd be interested in another test. Peace, Gene On Feb 14, 2009, at 11:30 AM, Jose Celestino wrote: Words by Gene Steinberg [Sat, Feb 14, 2009 at 02:58:06AM -0700]: On Feb 14, 2009, at 12:24 AM, Frank Bonnet wrote: Hello Does the debug mode give something understandable ? I've been reluctant to try this again, because this is a production server. But my admin and cPanel support say they can't find any reason for this. Is kind of dificult to get to a conclusion of what the problem may be without any further testing or any logs or traces. Do you have any lab where you can test a more recent version on the same hardware ? -- Jose Celestino | http://japc.uncovering.org/files/japc-pgpkey.asc "One man’s theology is another man’s belly laugh." -- Robert A. Heinlein
Re: [Dovecot] Strange Dovecot Issue with 64-bit AMD Processor
On Feb 14, 2009, at 12:24 AM, Frank Bonnet wrote: Hello Does the debug mode give something understandable ? I've been reluctant to try this again, because this is a production server. But my admin and cPanel support say they can't find any reason for this. Peace, Gene
[Dovecot] Strange Dovecot Issue with 64-bit AMD Processor
Folks, I welcome your insights into a strange issue that may involve a memory leak, but certainly involves a repeatable server crash. I have Dovecot installed as part of a cPanel installation. I think they're using 1.1.6 rather than the latest version, because they claim to need to test compatibility with their server software before deploying these components. In any case, I set up the latest cPanel on a 64-bit server running two quad-core AMD Opteron 2352 processors and CentOS 5.2 (64-bit). When I switch from the default Courier IMAP server to Dovecot, within 3 to 8 hours, IMAP resource usage will spike and ultimately the server will freeze. Restarting and returning to Courier solves the problem. The symptom is see in Top is that IMAP consumes 100% of memory, and the normal load (ranging from .05 to 1.50) soars to unheard of heights, such as 25, 50. Nothing will work on the server, which forces me to restart. Our email load is reasonably light, and all the sites on the server are mine. I have done fresh installs of cPanel and fresh updates without a solution. My server admin and cPanel support both appear stumped over this issue. While I am hesitant to install a newer version of Dovecot independently, I wanted to know if you're aware of any such difficulties. Since I'm back with Courier now, I presume logs aren't available (if they are let me know). But I never have problems with Courier, ever. I had Dovecot running fine with cPanel on a 32-bit Core2Duo server I use strictly for backup. I appreciate the lightweight footprint of Dovecot and its performance advantages, but if I can't get it to work on my server, I can't use it. Now maybe your newer versions solve this. Regardless, please provide whatever insights you can that might assist in tracking down this issue. Peace, Gene Steinberg
