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question on tcl.tk
by Jerry Geis 06 Jan '06

06 Jan '06

I am playing with tcl/tk on centso 4.2. I am trying to trap a signal and I get an error that invalid command name signal. My line is: signal trap SIGCONT ReadMessage where ReadMessage is a proc Is centos 4.2 missing a package or some thing for tcl? The example I found did not mention any restrictions. Any ideas, thank you. Jerry

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x86_64 and memory reservation
by Maciej Żenczykowski 06 Jan '06

06 Jan '06

Hi, I have an Athlon 64 2800+ with an ASUS K8V-MX mATX motherboard. 2x512 MB DDR400 Ram. Now the problem: 8MB of RAM is used by the shared memory of the video card, so I would expect 1016MB RAM to be available for Linux (that's how much the BIOS shows). Indeed if I go into memtest86+ v1.50 then I see: in e820-Std mode: 1015MB ram, with 432K reserved in e820-All mode: 1016MB ram, with 0K reserved This seems OK and everything works as expected. However when I boot CentOS 4.2 x86_64 (latest kernel) I end up with _way_ less available RAM - 21.5 MB is listed as reserved by the kernel - why??? To quote from dmesg: Memory: 1017796k/1040000k available (2398k kernel code, 21460k reserved, 1303k data, 164k init) This seems to make little sense... is this reserved area actually used by the kernel for something? or is it just sitting idly waiting for a better tomorrow? Cheers, MaZe.

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CentOS-announce Digest, Vol 11, Issue 1
by centos-announce-request＠centos.org 06 Jan '06

06 Jan '06

Send CentOS-announce mailing list submissions to centos-announce(a)centos.org To subscribe or unsubscribe via the World Wide Web, visit http://lists.centos.org/mailman/listinfo/centos-announce or, via email, send a message with subject or body 'help' to centos-announce-request(a)centos.org You can reach the person managing the list at centos-announce-owner(a)centos.org When replying, please edit your Subject line so it is more specific than "Re: Contents of CentOS-announce digest..." Today's Topics: 1. CESA-2006:0159 Moderate CentOS 4 ia64 httpd - security update (Pasi Pirhonen) 2. CESA-2006:0159 Moderate CentOS 3 ia64 httpd - security update (Pasi Pirhonen) 3. CESA-2006:0159 Moderate CentOS 4 axp httpd - security update (Pasi Pirhonen) 4. CESA-2006:0159 Moderate CentOS 3 i386 httpd - security update (Tru Huynh) 5. CESA-2006:0159 Moderate CentOS 3 x86_64 httpd - security update (Tru Huynh) 6. CESA-2006:0159 Moderate CentOS 4 x86_64 httpd - security update (Johnny Hughes) 7. CESA-2006:0159 Moderate CentOS 4 i386 httpd - security update (Johnny Hughes) 8. CESA-2006:0159 Moderate CentOS 4 s390(x) httpd - security update (Pasi Pirhonen) 9. CESA-2006:0159 Moderate CentOS 3 s390(x) httpd - security update (Pasi Pirhonen) 10. CESA-2006:0164 Critical CentOS 3 s390(x) mod_auth_pgsql - security update (Pasi Pirhonen) 11. CESA-2006:0164 Critical CentOS 3 ia64 mod_auth_pgsql - security update (Pasi Pirhonen) 12. CESA-2006:0164 Critical CentOS 4 ia64 mod_auth_pgsql - security update (Pasi Pirhonen) 13. CESA-2006:0164 Critical CentOS 4 s390(x) mod_auth_pgsql - security update (Pasi Pirhonen) 14. CESA-2006:0164 Critical CentOS 4 axp mod_auth_pgsql - security update (Pasi Pirhonen) ---------------------------------------------------------------------- Message: 1 Date: Thu, 5 Jan 2006 23:38:50 +0200 From: Pasi Pirhonen <upi(a)papat.org> Subject: [CentOS-announce] CESA-2006:0159 Moderate CentOS 4 ia64 httpd - security update To: centos-announce(a)centos.org Message-ID: <20060105213850.GA7374(a)core.upi.iki.fi> Content-Type: text/plain; charset="us-ascii" CentOS Errata and Security Advisory 2006:0159 https://rhn.redhat.com/errata/RHSA-2006-0159.html The following updated files have been uploaded and are currently syncing to the mirrors: files: updates/ia64/RPMS/httpd-2.0.52-22.ent.centos4.ia64.rpm updates/ia64/RPMS/httpd-devel-2.0.52-22.ent.centos4.ia64.rpm updates/ia64/RPMS/httpd-manual-2.0.52-22.ent.centos4.ia64.rpm updates/ia64/RPMS/httpd-suexec-2.0.52-22.ent.centos4.ia64.rpm updates/ia64/RPMS/mod_ssl-2.0.52-22.ent.centos4.ia64.rpm -- Pasi Pirhonen - upi(a)iki.fi - http://iki.fi/upi/

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RE: Linux HA may not be the best choice in your situation. [CentOS]High Availability using 2 sites
by Todd Reed 06 Jan '06

06 Jan '06

Ok...I see some of your points, but if SITE_A talked to SITE_B via the internet and they use a 1:1NAT, if the internet goes down at SITE_A, it breaks the 1:1 NAT. Servers down are different than the Internet connection being down. I never said RRD should be used for failover. I said it could be in combination with my idea. I guess it would help to know if the web services are serving only the company, or are they serving the public/Internet? --Todd -----Original Message----- From: centos-bounces(a)centos.org [mailto:centos-bounces@centos.org] On Behalf Of Bryan J. Smith Sent: Thursday, January 05, 2006 2:55 PM To: CentOS mailing list Subject: RE: Linux HA may not be the best choice in your situation. [CentOS]High Availability using 2 sites Todd Reed <treed(a)astate.edu> wrote: > As for Brian's Message: > 1) You are right, to a point. To what point? Round-robin DNS is not, and never will be, failover. And even some logic we've discussed here is rather subjective and arbitrary, even for one, specific app -- working on a corporate network (before considering across the Internet). > I'm not saying that my idea was a replacement for BGP. I even > state that by saying "This is no substitution for BGP". Again, I wish I would have _never_ said BGP. I mean an AS. > 2) You are correct in saying that you need to change in how > the world sees you (whether that be in the application or > layer3 routing). That can be done at the application layer or > at layer 3. But, if you are a small company that has only 1 > internet link at your primary site and 1 internet connection at > your remote site and you rely on the internet for > communications between the sites, then you technically do > not qualify for an AS number. That makes BGP useless. > That makes your solution be somewhere in the upper layer of > the OSI model. That's why I gave a _second_ recommendation. If you can guarantee your borders will _at_least_ be up, even if the servers behind it are down, you can implement 1-to-1 NAT at the border. I.e., if site A's servers are down, site A's border can use 1-to-1 NAT to target site B's servers. Please recognize I'm giving not just the "high end" solution, but I'm also giving a "feasible" solution for SMBs too. ;-> [ SIDE NOTE: I was _not_ the person who brough up Google either. But when someone did, I (as well as at least 1 other) showed that I wasn't off-the-mark on how Google does it either. ;-] > 3) My idea was more on the lines of internet failure at the > primary site and using RRDNS on top of that. If the secondary > DNS server kicked in and pulled it's configs from the hidden > master, then the hidden record wouldn't be configured for RRDNS > because it is only used when the primary site fails. The problem is _still_ propogation. That's why, in the absence of your own AS, you need the failed site to redirect all traffic under the guise of 1-to-1 NAT to the site that is up. It's very simple to do, and they even have affordable devices to do so with Linux+ASICs (i.e., faster than a host-based Linux solution). > 4) My idea was also an application layer solution. > Last time I checked, BGP was in Layer 3. Forget I even mentioned ASNs for a moment. I _also_ mentioned using 1-to-1 NAT between sites, and it works _well_ too. It not only _avoids_ the propogation issue, but better yet, it work work _while_ propogation is still occuring. > 5) Yes, there are some delays when using DNS. Likewise > there are delays with BGP. Certainly BGP delays are a lot > quicker. No argument there. Sigh, you're not getting my point at all on layer-3. You've totally missed it. It's not comparable to application-level. It's absolute. > But again, my idea is looking at it from an application layer > POV. _Eventually_ you'd have to change the application-layer as well, _if_ the site was down awhile. But in the meantime, you _need_ to do layer-3 redirection for the immediate failover. 1-to-1 NAT does this. It's very simple. It just works. -- Bryan J. Smith Professional, Technical Annoyance b.j.smith(a)ieee.org http://thebs413.blogspot.com ---------------------------------------------------- *** Speed doesn't kill, difference in speed does *** _______________________________________________ CentOS mailing list CentOS(a)centos.org http://lists.centos.org/mailman/listinfo/centos

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RE: Linux HA may not be the best choice in yoursituation. [CentOS]High Availability using 2 sites
by Todd Reed 06 Jan '06

06 Jan '06

In a nutshell and very first of all, you need at least 2 internet connections. Those ISP must be willing to setup BGP peering between your routers and theirs. Once that agreement has been made, you need to get their AS Numbers and submit the ASN request located on ARIN's website (http://www.arin.net) After some paperwork and money exchanges, ARIN assigns you an AS number. At that point, you can configure the BGP peering. There's more details to it, but that's what I went through in a nutshell. ARIN has a pretty good flowchart of their process located at http://www.arin.net/education/asn_process/index.html --Todd -----Original Message----- From: centos-bounces(a)centos.org [mailto:centos-bounces@centos.org] On Behalf Of Tim Edwards Sent: Thursday, January 05, 2006 6:33 PM To: CentOS mailing list Subject: Re: Linux HA may not be the best choice in yoursituation. [CentOS]High Availability using 2 sites Bryan J. Smith wrote: > Exactly! That's why I keep both agreeing _and_ dismissing > many suggestions, because most are only feasible _if_ they > are for a corporate intranet. Most are too arbitrary for the > Internet. > > I believe the original poster was talking about the Internet, > but I could be wrong. Yes I am talking about the Internet, not an Intranet. Thanks for all your replies, especially Brian, they've helped me see more clearly what the options are. I'd already given up on Round Robin or any other kind of DNS 'solution' before I posted, after reading this: http://homepages.tesco.net./~J.deBoynePollard/FGA/dns-round-robin-is-use less.html I don't think the difficulties and expense of getting an AS number and setting up BGP to work with our ISP will be worth it, but I'm not sure - what steps exactly are involved in doing that? -- Tim Edwards _______________________________________________ CentOS mailing list CentOS(a)centos.org http://lists.centos.org/mailman/listinfo/centos

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CentOS x64 crashed
by Fong Vang 06 Jan '06

06 Jan '06

I just installed CentOS 4.2 x64 bit version. After installaton, the system boots but kernel panics with this message: Badness in i8042_panic_blink at drivers/input/serio/i8042.c:992 The kernel seems to load completely. It gets passed the point where it prompts to press "I" for interactive mode. Something after that probably caused a module to load that crashed the kernel. Any idea what to do to get around this? Thanks for any help. FONGVANG

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High Availability using 2 sites
by Tim Edwards 06 Jan '06

06 Jan '06

We currently have a backup site at a different location to our main site. This backup site mirrors (as closely as possible) our main services, particularly web serving. Is there a way to have the backup site act as a failover for the main site using something like Linux-HA? They are on seperate internet connections with different IP ranges. Thanks -- Tim Edwards

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rc script not running on shutdown
by Mark Belanger 06 Jan '06

06 Jan '06

I've create a script and associated links(via chkconfig). The script runs in the expected runlevels at boot time, but does not run at all during shutdown(halt, reboot, etc). I swear I've done this a million times. What am I overlooking? # cat /etc/issue CentOS release 3.5 (Final) Kernel \r on an \m # chkconfig --list chnghst chnghst 0:off 1:on 2:off 3:off 4:off 5:off 6:off localhost:# find /etc/rc* |grep chngh /etc/rc.d/init.d/chnghst /etc/rc.d/rc0.d/K07chnghst /etc/rc.d/rc1.d/S10chnghst /etc/rc.d/rc2.d/K87chnghst /etc/rc.d/rc3.d/K07chnghst /etc/rc.d/rc4.d/K07chnghst /etc/rc.d/rc5.d/K07chnghst /etc/rc.d/rc6.d/K07chnghst # uname -a Linux localhost 2.4.21-32.ELsmp #1 SMP Wed May 18 17:49:28 EDT 2005 i686 i686 i386 GNU/Linux tia, -mark -- Mark Belanger LTX Corporation

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RE: Linux HA may not be the best choice inyoursituation. [CentOS]High Availability using 2 sites
by Todd Reed 06 Jan '06

06 Jan '06

One final consideration I forgot to mention, make sure you have a beefy router. Depending on your BGP configurations, if you want to receive all routes from the internet, that can seriously bog down a low end router. I'm not saying you can't get by with a low-end router, just make sure your router can handle the results of your BGP configs. --Todd -----Original Message----- From: centos-bounces(a)centos.org [mailto:centos-bounces@centos.org] On Behalf Of Todd Reed Sent: Thursday, January 05, 2006 7:01 PM To: CentOS mailing list Subject: RE: Linux HA may not be the best choice inyoursituation. [CentOS]High Availability using 2 sites In a nutshell and very first of all, you need at least 2 internet connections. Those ISP must be willing to setup BGP peering between your routers and theirs. Once that agreement has been made, you need to get their AS Numbers and submit the ASN request located on ARIN's website (http://www.arin.net) After some paperwork and money exchanges, ARIN assigns you an AS number. At that point, you can configure the BGP peering. There's more details to it, but that's what I went through in a nutshell. ARIN has a pretty good flowchart of their process located at http://www.arin.net/education/asn_process/index.html --Todd -----Original Message----- From: centos-bounces(a)centos.org [mailto:centos-bounces@centos.org] On Behalf Of Tim Edwards Sent: Thursday, January 05, 2006 6:33 PM To: CentOS mailing list Subject: Re: Linux HA may not be the best choice in yoursituation. [CentOS]High Availability using 2 sites Bryan J. Smith wrote: > Exactly! That's why I keep both agreeing _and_ dismissing > many suggestions, because most are only feasible _if_ they > are for a corporate intranet. Most are too arbitrary for the > Internet. > > I believe the original poster was talking about the Internet, > but I could be wrong. Yes I am talking about the Internet, not an Intranet. Thanks for all your replies, especially Brian, they've helped me see more clearly what the options are. I'd already given up on Round Robin or any other kind of DNS 'solution' before I posted, after reading this: http://homepages.tesco.net./~J.deBoynePollard/FGA/dns-round-robin-is-use less.html I don't think the difficulties and expense of getting an AS number and setting up BGP to work with our ISP will be worth it, but I'm not sure - what steps exactly are involved in doing that? -- Tim Edwards _______________________________________________ CentOS mailing list CentOS(a)centos.org http://lists.centos.org/mailman/listinfo/centos _______________________________________________ CentOS mailing list CentOS(a)centos.org http://lists.centos.org/mailman/listinfo/centos

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Re[4]: [CentOS] *tangent* High Availability using 2 sites -- yep, "propogation."
by Mickael Maddison 06 Jan '06

06 Jan '06

Hello Les, Thanks for that info. I'm playing with this now and although the 'failover' process seems rather slow, it does seem to be doing what I need. I setup a subdomain entry to point to 4 IP's, only one if which is actually working, and indeed, when IE get's a non-active IP, it eventually goes to the next one until it finally finds the actual live IP. Once it gets the live one, the site works as expected (of course). I'm glad I stumbled onto this thread... for my client's current need, this will do the trick nicely. -- Best regards, Mickael mailto:mikelists@silverservers.com Thursday, January 5, 2006, 12:05:19 PM, you wrote: > On Thu, 2006-01-05 at 13:33, Mickael Maddison wrote: >> Forgive me for this sidestep, but you are saying that Windows/IE >> actually ignores bad IP addresses if a site lists multiple IP's in a >> DNS lookup? I tried this approach for some redundancy a couple years >> ago and it didn't seem to work as you suggest. If it has indeed >> changed to work that way, this will help one of my clients immensely. > The versions of IE I've tried have been very good at this although > it doesn't work for other stock windows apps. You may need > to make sure that ICMP 'unreachable' packets are not firewalled > so down hosts are detected quickly. You can test it easily by > setting up a dummy DNS name with a bunch of A records where some > point to working servers and some don't.

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