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Because not enough information exists in easy-to-find searches: as a simple reminder – SCSI device IDs can and will change.

A few months ago I hot-added a new disk to an ssh bastion host (a VM on ESX). As these things tend to go, I eventually took a maintenance window and updated firmware/BIOS/OS on the ESX host. When the bastion VM came back online, however, I was presented with an odd error:

[root@bastion ~]: fsck /dev/sdc1
e2fsck 1.39 (29-May-2006)
fsck.ext3: Device or resource busy while trying to open /dev/sdc1
Filesystem mounted or opened exclusively by another program?
[root@oracle1 ~]# cat /proc/mounts
rootfs / rootfs rw 0 0
/dev/root / ext3 rw,data=ordered 0 0
/dev /dev tmpfs rw 0 0
/proc /proc proc rw 0 0
none /selinux selinuxfs rw 0 0
devpts /dev/pts devpts rw 0 0
tmpfs /dev/shm tmpfs rw 0 0
none /proc/sys/fs/binfmt_misc binfmt_misc rw 0 0
sunrpc /var/lib/nfs/rpc_pipefs rpc_pipefs rw 0 0
[root@oracle1 ~]# cat /etc/fstab
/dev/main/root / ext3 defaults 1 1
/dev/sdc1 /home ext3 defaults 1 2
/dev/main/var /var ext3 defaults 1 2
/dev/main/tmp /tmp ext3 defaults 1 2
LABEL=/boot /boot ext3 defaults 1 2
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
/dev/main/swap swap swap defaults 0 0
# Beginning of the block added by the VMware software
.host:/ /mnt/hgfs vmhgfs defaults,ttl=5 0 0
# End of the block added by the VMware software

So everything in the fstab is how I left it – /dev/sdc1 is the new disk I added that is giving errors mounting. So I thought to check for corruption on the disk, and found the problem:

[root@oracle1 ~]# fdisk -l
Disk /dev/sda: 42.9 GB, 42949672960 bytes
255 heads, 63 sectors/track, 5221 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 5221 41833260 8e Linux LVM
Disk /dev/sdb: 42.9 GB, 42949672960 bytes
255 heads, 63 sectors/track, 5221 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 5221 41937651 83 Linux
Disk /dev/sdc: 32.2 GB, 32212254720 bytes
255 heads, 63 sectors/track, 3916 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 * 1 3917 31457279+ 8e Linux LVM


So, a simple fix – change “/dev/sdc1″ to “/dev/sdb1″ in /etc/fstab (or to VOLUME=home), and boot back up.

It’s not something that’ll probably happen on this server again, but it is something to be aware of, on both VM guests and on physical servers. This is why so many newer Linux OSes are using UUID= or VOLUME= instead of device path for SCSI disks.

It used to be that you could edit /etc/modprobe.d/blacklist and add “blacklist pcspkr” to turn off the console beeps entirely on Ubuntu / Kubuntu.  As of 9.04, the module is now called “snd_pcsp”.

So, to turn off console (not X terminal, but tty) beeps, you can do one of the following:
1) (This is my preference)

echo blacklist snd_pcsp >> /etc/modprobe.d/blacklist.conf


2) (I’ve done this, but it doesn’t affect all software)

for i in 1 2 3 4 5 6
do
setterm -blength 0 > /dev/tty$i
done

3) (Only works per shell if ~/.inputrc is included)

echo set bell-style visible >> ~/.inputrc


Enjoy more-sane editing from ttyX in the future!

I just finished my upgrade from Kubuntu 8.04 to 8.10 this past week (since I had downtime from work, I could afford to break things for a few days).  The upgrade went great, and I’ll write about it shortly, once I get used to the newness.

Anyways; Workstation 6.5 has been giving me problems.  Because of the newness of KDE4, I initially thought it was a KDE problem, but it turns out it’s something between Workstation 6.5 and Ubuntu 8.10.  I just ran the “adapt –dist-upgrade-devel” command from the Ubuntu wiki to upgrade, and upon reboot, I couldn’t “ctrl-alt-ins” or “ctrl-alt-del” to log into my Windows VM, my “Windows/Start” key on the keyboard wouldn’t respond, and my arrow keys wouldn’t work.  Incredibly, when I’d hit the “down” arrow, I’d get the Windows Start menu pop up!!

Fix is easy, edit /etc/vmware/config and add the line below like:

sudo vim /etc/vmware/config
:$
A (that's vi-command for "go to the end of the file, and start writing a new line")
xkeymap.nokeycodeMap = true


Have to restart your VMs for this change to take effect. Thanks to Duncan Epping for this fix (he posted it in the forums, where I found it).

In the Windows world, tools like Group Policy, System Center Configuration Manager, and DesktopAuthority, among others, have been around for 8 or more years to allow fast simple deployment of software and updates to remote computers, or force tasks to be run on remote computers.

For the Unix/Linux world, there doesn’t seem to be as much available.

If you have a pure HP-UX shop, there is HP Systems Insight Manager (SIM) with plug-ins available for software deployment, and I believe IBM Tivoli has a function or sub-product which does the same thing if you have all AIX systems. Red Hat Network has a feature to allow commands to be run on your servers, but only whenever they check in with the RHN or your internal Satellite Server (much like Group Policy, except GPO doesn’t allow “in the middle of the day” script creation without GP-Preferences). So what’s available that’s like SCCM or DesktopAuthority – a “click now and do this thing” tool?

A bunch of my customers just have various levels of logging and processing that come down to being a big for loop that ssh’s into a server and runs a command:
for i in `cat server-list.txt` ; do scp scriptname $i:/root/; ssh $i "/root/scriptname" | tee logfile-$i.log; done;
While it works great for smaller commands. if you have a mixed environment, the “scriptname” script has to be intelligent enough to know what it’s running against, or your “server-list.txt” has to be broken up by class of system. In either case, if you have 200 systems in the list, and the task takes 5 minutes per server, a single install will run for 16-17 hours.

Software like Likewise Enterprise which allow Group Policy management to remote computers is great, because you can have guaranteed delivery and execution of your script or command in (by default) 30 minutes, but my problem is how to get it there in the first place?

So, administrators out there in companies with 1000, 4000, 10000+ servers (or even Desktops), what mutli-threaded or multi-process tool are you using to tackle this timing/resouce problem? Please post below!

I ran into a problem today where I couldn’t remember the native packet capture tool for Solaris and couldn’t install tcpdump, so i thought I’d put down as many as many native packet capture commands as I knew, by OS, in a single place.  I’ll update this as I find more, since there’s hundreds of Operating systems out there.

• AIX: iptrace: /usr/sbin/iptrace [ -a ] [ -b ][ -e ] [ -u ] [ -PProtocol_list ] [ -iInterface ] [ -pPort_list ] [ -sHost [ -b ] ] [ -dHost ] [ -L Log_size ] [ -B ] [ -T ] [ -S snap_length] LogFile
• FreeBSD: tcpdump (I think): tcpdump [ -adeflnNOpqRStuvxX ] [ -c count ] [ -C file_size ] [ -F file ] [ -i interface ] [ -m module ] [ -r file ] [ -s snaplen ] [ -T type ] [ -w file ] [ -E algo:secret ] [ expression ]
• HP-UX: nettl: nettl requires a daemon start, and other setup: /usr/sbin/nettl -traceon kind… -entity subsystem… [-card dev_name...] [-file tracename] [-m bytes] [-size portsize] [-tracemax maxsize] [-n num_files] [-mem init_mem [max_mem]] [-bind cpu_id] [-timer timer_value]
• Linux 2.4 and higher:
  • tcpdump (some distros): tcpdump [ -AdDefKlLnNOpqRStuUvxX ] [ -c count ] [ -C file_size ] [ -G rotate_seconds ] [ -F file ] [ -i interface ] [ -m module ] [ -M secret ] [ -r file ] [ -s snaplen ] [ -T type ] [ -w file ] [ -W filecount ] [ -E spi@ipaddr algo:secret,... ] [ -y datalinktype ] [ -z postrotate-command ] [ -Z user ] [ expression ]
  • wireshark (some distros, used to be called “ethereal”): GUI-config, no command-line, use tethereal (now tshark) for that
  • tshark: tshark [ -a <capture autostop condition> ] … [ -b <capture ring buffer option>] … [ -B <capture buffer size (Win32 only)> ]  [ -c <capture packet count> ] [ -C <configuration profile> ] [ -d <layer type>==<selector>,<decode-as protocol> ] [ -D ] [ -e <field> ] [ -E <field print option> ] [ -f <capture filter> ] [ -F <file format> ] [ -h ] [ -i <capture interface>|- ] [ -l ] [ -L ] [ -n ] [ -N <name resolving flags> ] [ -o <preference setting> ] … [ -p ] [ -q ] [ -r <infile> ] [ -R <read (display) filter> ] [ -s <capture snaplen> ] [ -S ] [ -t ad|a|r|d|e ] [ -T pdml|psml|ps|text|fields ] [ -v ] [ -V ] [ -w <outfile>|- ] [ -x ] [ -X <eXtension option>] [ -y <capture link type> ] [ -z <statistics> ] [ <capture filter> ]
• Mac OSX: tcpdump (among others): tcpdump [ -adeflnNOpqRStuvxX ] [ -c count ] [ -C file_size ] [ -F file ] [ -i interface ] [ -m module ] [ -r file ] [ -s snaplen ] [ -T type ] [ -w file ] [ -E algo:secret ] [ expression ]
• Solaris: snoop: snoop [ -aPDSvVNC ] [ -d device ] [ -s snaplen ] [ -c maxcount ] [ -i filename ] [ -o filename ] [ -n filename ] [ -t [ r | a | d ] ] [ -p first [ , last ] ] [ -x offset [ , length ] ] [ expression ]
• Windows 2000, XP, 2003, Vista, 2008 and beyond:
  • netmon (not installed by default): GUI config, filter creation info here
  • wireshark (available by download): GUI-config, no command-line

Any others anyone wants added (or corrected), just comment or email and I’ll update this.
(Edit 7/29/08 – change tcpdump link)
(Edit 10/13/08 – add tshark info, thanks Jefferson!, and wireshark on Windows)
(Edit 12/27/09 – update IBM iptrace man page link)