totalnetsolutions.net

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.

First written on Twitter:

@docsmooth: Signs of twitspam: bio is tinyurl; <100 updates, >200 following/ers;all updates “from twitfeed”, inc. link; no conversation. Check yourself!

I just went through my followers list on twitblock.org and thought I’d write a bit deeper on this subject.

Ways to determine a twitter spammer – higher scores are more likely spammers:

• Bio link is tinyurl or bit.ly or other URL shortener. There is *never* a reason to put this in your URL link on Twitter, unless you’re hiding the destination. +10 pts
• you have more than 200 “friends” and less than 100 updates. +2 pts
• you have a follower/following ratio below. .5 +2pts
• Every single tweet has a link. +5 pts
• Every single tweet is from TwitFeed. +5 pts
• More than 2 tweets are from an unregistered API app. +8 pts
• You have never @replied anyone. +1 pts

I generally block anyone above a “9″ score on this scale.

(cross-posted from my personal blog as well)

Upgrading software – always required to keep things secure.  Windows, Wordpress, Mac OSx, Linux, Office, Firefox, etc.  So I just finished upgrading TotalNetSolutions.net again.  Hopefully I’ll be able to be better about this, now that Wordpress does the automatic upgrades now.

I’ve been doing the automatic upgrades on one of my other sites since they came out.  They’re easy, fast, and even more painless than the 3-step upgrade that works so well. So now, I should be able to keep TNS much further away from the “cobbler’s kids” syndrome so many small company’s systems suffer with.

I’ve been using TweetDeck as a Twitter client for a while now, and love it. I recently updated my main laptop from Kubuntu 8.04 to Kubuntu 9.04, and even though the ATI x1300 3d driver is broken, I’m finally getting all the little annoyances fixed up.

The biggest issue I had, though, was after the upgrade, TweetDeck was just showing a blank window, with only the “Tweet/All Friends/Replies/Direct Messages/Groups/Favorites” etc. buttons on the top. There are a lot of posts about how to run Adobe Air and TweetDeck on x64 Ubuntu, but this is a 32-bit machine, so those fixes weren’t working.

The fix is surprisingly simple: make sure kwallet is running with an open wallet. Full details in a nice concise post from Peter Upfold, here. One of his commenters mentioned an issue, but I believe it turned out to be a “no wallets were open” problem. Thanks Peter!

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!