Joril's questions

I have a newly installed CentOS 6.6 two-node cluster using Pacemaker. Every 10 seconds /var/log/pacemaker.log shows this "Changed active directory to /var/lib/pacemaker/cores/root" message (and nothing else):

May 28 11:04:15 [2671] cluster1 crmd:     info: crm_log_init:   Changed active directory to /var/lib/pacemaker/cores/root
May 28 11:04:25 [3087] cluster1 crmd:     info: crm_log_init:   Changed active directory to /var/lib/pacemaker/cores/root
May 28 11:04:35 [3504] cluster1 crmd:     info: crm_log_init:   Changed active directory to /var/lib/pacemaker/cores/root

Is this normal? Is there a way to stop it?

I've just installed a Mailman server to send newsletters, but I (foolishly) didn't wait long enough for the new dedicated subdomain to propagate through the DNS network before sending the first one, so now I have a lot of bounced emails :( (due to Sender address rejected: Domain not found (in reply to RCPT TO command))

Since about half of the emails went through anyway, is it possible to tell Mailman to re-send the bounced ones, now that the DNS issue is settled?

Here's the Postfix log for one of those bounced emails:

Oct 30 10:07:02 localhost postfix/smtpd[28548]: 47C5EC4134: client=localhost[127.0.0.1]
Oct 30 10:07:02 localhost postfix/cleanup[28580]: 47C5EC4134: message-id=<[email protected]>
Oct 30 10:07:02 localhost postfix/qmgr[14515]: 47C5EC4134: from=<[email protected]>, size=431670, nrcpt=1 (queue active)
Oct 30 10:07:02 localhost postfix/smtp[28562]: 47C5EC4134: to=<[email protected]>, relay=smtp.XXX.com[XX.XXX.X.XXX]:25, delay=0.42, delays=0.05/0/0.21/0.16, dsn=4.1.8, status=deferred (host smtp.XXX.com[XX.XXX.X.XXX] said: 450 4.1.8 <[email protected]>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Oct 30 10:16:20 localhost postfix/qmgr[14515]: 47C5EC4134: from=<[email protected]>, size=431670, nrcpt=1 (queue active)
Oct 30 10:16:20 localhost postfix/smtp[29719]: 47C5EC4134: to=<[email protected]>, relay=smtp.XXX.com[XX.XXX.X.XXX]:25, delay=558, delays=558/0.06/0.1/0.04, dsn=4.1.8, status=deferred (host smtp.XXX.com[XX.XXX.X.XXX] said: 450 4.1.8 <[email protected]>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Oct 30 10:26:20 localhost postfix/qmgr[14515]: 47C5EC4134: from=<[email protected]>, size=431670, nrcpt=1 (queue active)
Oct 30 10:26:20 localhost postfix/smtp[30860]: 47C5EC4134: to=<[email protected]>, relay=smtp.XXX.com[XX.XXX.X.XXX]:25, delay=1159, delays=1158/0.03/0.34/0.05, dsn=4.1.8, status=deferred (host smtp.XXX.com[XX.XXX.X.XXX] said: 450 4.1.8 <[email protected]>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Oct 30 10:46:20 localhost postfix/qmgr[14515]: 47C5EC4134: from=<[email protected]>, size=431670, nrcpt=1 (queue active)
Oct 30 10:46:21 localhost postfix/smtp[320]: 47C5EC4134: to=<[email protected]>, relay=smtp.XXX.com[XX.XXX.X.XXX]:25, delay=2359, delays=2359/0.03/0.1/0.04, dsn=4.1.8, status=deferred (host smtp.XXX.com[XX.XXX.X.XXX] said: 450 4.1.8 <[email protected]>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Oct 30 11:16:20 localhost postfix/qmgr[14515]: 47C5EC4134: from=<[email protected]>, size=431670, nrcpt=1 (queue active)
Oct 30 11:16:20 localhost postfix/smtp[3133]: 47C5EC4134: to=<[email protected]>, relay=smtp.XXX.com[XX.XXX.X.XXX]:25, delay=4158, delays=4158/0.03/0.1/0.06, dsn=4.1.8, status=deferred (host smtp.XXX.com[XX.XXX.X.XXX] said: 450 4.1.8 <[email protected]>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Oct 30 11:16:20 localhost postfix/qmgr[14515]: 47C5EC4134: from=<[email protected]>, status=expired, returned to sender
Oct 30 11:16:20 localhost postfix/bounce[3136]: 47C5EC4134: sender non-delivery notification: 9CFC2C0560
Oct 30 11:16:20 localhost postfix/qmgr[14515]: 47C5EC4134: removed

We have an Hylafax 5.2.5 CentOS 5 installation hosted inside a Xen virtual machine. It works quite well, but now I'm in the process of upgrading/migrating it to a KVM virtual machine running Ubuntu 10.04 and Hylafax 5.5.1 (compiled from source using http://sourceforge.net/projects/hylafax/files/hylafax%20debian%20build%20files/ )

The problem I'm having is that - while receiving works fine - sending faxes is extremely unreliable, I get lots of "No response to MPS repeated 3 tries", or "Failure to transmit clean ECM image data."

The line, modem and configuration files I'm using are the same as before, so I thought that it could be a KVM scheduling issue, but even setting cpu_shares to 10240 instead of 1024 doesn't change a thing... What else could I try?

Here's an example log file http://pastebin.com/cN01cpEs

I have a Bacula setup with 9 clients, and it's working happily. Today I had to add another client, so I went and copied+adapted the existing configuration files from another client, but when I schedule a job for the new client, I get these errors:

20-Mar 17:50 tools-dir JobId 39: Start Backup JobId 39, Job=BackupPresenze2.2012-03-20_17.50.49_04
20-Mar 17:50 tools-dir JobId 39: Using Device "FileStorage"
20-Mar 17:50 presenze2-fd JobId 39: Fatal error: Failed to connect to Storage daemon: bacula.mylan.local:9103
20-Mar 17:50 tools-dir JobId 39: Fatal error: Bad response to Storage command: wanted 2000 OK storage
, got 2902 Bad storage

From the client I can telnet to bacula.mylan.local:9103 just fine, and jobs for other clients work successfully... What could I check?
(Server and client run Ubuntu 10.04, if it's relevant)

I'm building a simple 2-node cluster with Ganeti+DRBD... What is the recommended way to setup automatic failover?
I'm used to Heartbeat, but they say it should be avoided with my setup.

I have an home web server that I use to serve a few pages for personal purposes. The server runs Ubuntu and is behind an ADSL connection, and it's working nicely.
Recently I subscribed to a Hiperlan connection and added a router for it to my LAN. So the situation is this:

• Web server (Ubuntu Hardy)
• My workstation
• ADSL router (still connected, used by the server)
• Hiperlan router (Linksys WRT54G v2.2 running Gargoyle/OpenWRT, used by the workstation)

Right now I'm trying to configure the new router to handle port forwarding so that I can remove the old router, but I'm hitting a problem. Basically, if I try to telnet my Hiperlan-IP address from outside (via an OpenVPN connection to my office), telnet hangs there... I did a tcpdump on the server, here it is (.254 is the web server):

20:07:53.795370 IP my.externalhost.38195 > 192.168.7.254.www: S 2766630416:2766630416(0) win 5840 <mss 1460,sackOK,timestamp 924929110 0,nop,wscale 7>
20:07:53.795426 IP 192.168.7.254.www > my.externalhost.38195: S 1526241928:1526241928(0) ack 2766630417 win 5792 <mss 1460,sackOK,timestamp 888004836 924929110,nop,wscale 6>
20:07:53.837928 IP my.host.38195 > 192.168.7.254.www: R 2766630417:2766630417(0) win 0

I think this means that after the server responds to the first "question" of the client, something goes awry and the client asks to reset the connection... How could I find what's going on? I tried disabling the firewall on the server (ufw disable) but nothing changes... Anyway, if I try to telnet the same IP from inside the LAN, it works.

I'd like to block malformed requests like these:

79.26.188.208 - - [05/Apr/2011:13:47:38 +0200] "\xae\xe1\x0fi\xca\xeba\xdfm\x9d\xb5\xc0yr-n\x05Z\x9f\xa7\x05\xa1g" 200 4855 "-" "-"
82.51.130.83 - - [05/Apr/2011:18:25:38 +0200] "T\xd0\xc55\xc3A\xcd\xd0" 200 4855 "-" "-"

What is the preferred method?

Our company site just went live and the very first entry in access.log looks like a tentative exploit :) Any idea on which one it could be?
Here's the relevant line:

79.168.7.121 - - [28/Jan/2011:13:19:25 +0100] "Z\xc0\xf5\x95\xb8Un\xff\x9ecA\xd1\xc2/\xfc\x94n\x8epeM\xdc\x18#\xb3\xc8\xa5\xbe)\xbci\xe2\xf5\x02,\x97\xc0\x96\x9e\xa9\xf8;i\x1a\x86\x01" 200 4855 "-" "-"

I've just installed an Ubuntu Lucid 64bit image (from Stacklet) as a Xen DomU, running under Xen 3.2.1 on Centos 5.2 64bit.
Everything is working fine, except my logs are flooded with:

/dev/hvc0: No such file or directory

I tried creating the device with mknod /dev/hvc0 c 229 0 but the message just changes to:

/dev/hvc0: cannot open as standard input: No such device or address

Any hint on what I could try? :(

I have an old PC that I'd like to use as an LTSP client, but its BIOS cannot boot from the network... I tried booting from a CDROM containing a gxpe (Etherboot) image downloaded from ROM-o-matic and it works, so my question is: how do I install the image directly to the local hard disk?

we have a two-node cluster using DRBD 8.2 on CentOS 5.2 64bit. The cluster runs a few VMs on top of Xen 3.2.1, here's the configuration for an Ubuntu Jaunty VM:

name = 'dev'
bootloader = '/usr/bin/pygrub'
memory = '512'
vif = [ 'ip=192.168.1.217,mac=00:16:3E:CD:60:80' ]
disk = [ 'phy:/dev/drbd24,xvda1,w',
              'phy:/dev/drbd25,xvda2,w' ]

As you can see, the disks are specified like "phy:", and as such pygrub doesn't know a thing about the underlying drbd device...
So my problem is that even though the VM boots just fine, it doesn't handle the state of the drbd device. As a result, when for some reason the device gets to a secondary/secondary state, the VM won't boot, and I have to manually specify which node is primary.

I read that starting with Xen 3.3 pygrub understands the "drbd:" specification, and I think that it would fix my problem, but I can't upgrade Xen at the moment... Is there a workaround? For example, could I use the 3.3 version of pygrub?

Thanks!

I'm thinking of setting up LDAP+NFS to handle centralized /home directories for our LAN users, but I was wondering, what would happen upon login from multiple machines with the same user? Are there risks of data corruption? If so, is there a way to prevent it?

(Clients and server would use Ubuntu)

I am the admin of a small LAN of 10+ computers. I've set up a dnsmasq server for DHCP and DNS resolution, and it's working almost fine..
My problem is that when I try to use Google images, sometimes it takes ages to show the actual images. I get just the textual part of the page (menus and so on) while the images themselves are shown as the still-loading-white boxes..

When I use the DSL router directly as DNS, the site works fine all the time.

The problem sometimes presents itself with Google maps too.. The map takes ages to load.

Any idea on what I could try to troubleshoot this?

(dnsmasq 2.47 on CentOS 5.2 64bit, our outside connection is an asymmetrical 4Mbps DSL)

I'm trying to boot an Ubuntu Jaunty VM using Xen 3.2.1 on CentOS 5.2.

I followed this guide to setup the VM, the debootstrap call I used was:

debootstrap --arch amd64 --include=linux-image-server,grub --components=main,universe,multiverse jaunty /mnt/xenfs http://it.archive.ubuntu.com/ubuntu/

My problem is that when I try to boot the VM, I can see Grub showing the kernel list, but when I choose one, the boot stops with this error:

Error: (2, 'Invalid kernel', 'xc_dom_find_loader: no loader found\n')

Here's the Xen configuration for the VM:

name = 'testvm'
bootloader = '/usr/bin/pygrub'
memory = '256'
vif = [ 'ip=192.168.1.216,mac=00:16:3E:21:C2:A1' ]
disk = [ 'phy:/dev/drbd22,xvda1,w',
              'phy:/dev/drbd23,xvda2,w' ]

...and the relevant part from /boot/grub/menu.lst:

title           Ubuntu 9.04, kernel 2.6.28-11-server                            
root           (hd0,0)                                                         
kernel        /boot/vmlinuz-2.6.28-11-server root=/dev/xvda1 ro console=xvc0  
initrd         /boot/initrd.img-2.6.28-11-server                               

Inspecting the kernel shows:

[root@server2 boot]# file vmlinuz-2.6.28-11-server 
vmlinuz-2.6.28-11-server: Linux kernel x86 boot executable RO-rootFS, root_dev 0x801, swap_dev 0x3, Normal VGA

So the kernel is not a gzipped file.. Maybe that's a format that Xen 3.2.1 doesn't understand? I can't upgrade to Xen 3.3... Is there a way to "transform" that kernel into a gzipped image? Should I try another kernel altogether?

Many thanks!

I'm looking for a free solution that runs on Ubuntu and allows to remotely manage an Ubuntu desktop (local display :0), even at the login/gdm phase.. What would you recommend?
Many thanks!

(For the record, right now I'm using x11vnc but it doesn't look very stable when started from gdm)

I have an extension for Thunderbird that I'd like to install automatically from a script - since I have to do it on all our workstations - is there a way to do that?
Thanks!

(Ubuntu 9.04)

I have a VNC server (x11vnc) configured to allow me to log into the machine at the local display (:0) via SSH tunnel, following the instructions here.
My question: is there a way to create the tunnel AND launch vncviewer with a single command/script?

Here's how I'm launching x11vnc from /etc/gdm/Init/Default:

x11vnc -localhost -nopw -ncache 0 -o /var/log/x11vnc.log -forever -bg

Edit: please note that in this way x11vnc starts from gdm, so that I can log into the local session myself.

(Server and client: Xubuntu 9.04)