JLime Linux - WiFi Scanning, New Userland, etc...

Almost all of the problems I was initially having with jlime were due to the fact that when I downloaded it, they were in the middle of a big update with an experimental kernel and an old base userland image. After pulling down the new userland and going to a known-stable kernel, everything seems to be rockin' and rollin' with jLime on my Hewlett Packard Jornada 720.

Case and point, X now has a decent interface, desktop icons, and Torsmo status monitor works great (finally!)


I was also having problems with package management. Those were also resolved by installing fresh from the current userland image. The packages are also pretty up-to-date with a quite extensive list of things to choose from. Want nmap? MySQL? OpenSSH? No problem! Kismet for War-driving? Just say the word! Here's my J720 running Kismet with a Senao Engenius 200mW Long-range 802.11b card attached to a pair of 19dBi omni-directional magnet mount antennae.



And a close-up of the screen:


All this, and my battery lasts for hours upon hours, even with the wireless card installed. I actually have nothing left to complain about at all aside from the fact that 32MB of RAM and 206 MHz is still a somewhat anemic machine for web browsing. For light-weight stuff like checking e-mail, managing servers via SSH and the like, this seems to be just about the most handy thing I've seen in a very long time.

I'm working on getting a data cable for my new GPS so that I can really put this thing to the test when it comes to war-driving. I haven't ever used kismet for serious network location. I'm more of a Mac OS X and BSD guy at heart, so KisMAC and BSD-Airtools are my typical weapons of choice.

It's simply amazing to me, though, to see this kind of development happening for a family of portable computers that's been more or less dead for the better part of a decade. Where I was once drooling over the OLPC and EEePC, I'm now finding that I have all of the ultra-mobile goodness I really need right here in a package that's admittedly slower but also lighter, smaller and longer lasting.

ApacheFriends XAMPP makes Apache setup easy

I've been using XAMPP on Windows (which I'm forced to use at work) for a few years. I write a lot of custom PHP stuff to help me with my day job, and I also like to test functions or classes I write before I push it out to production. ApacheFriends XAMPP is an easy way to get a basic Apache installation up and running with some of the most popular add-ons including PHP and MySQL. It installs in OS X and many Linux distributions as well.

While nothing can replace a streamlined, custom-compiled AMP Stack set up just the way you need it, XAMPP affords busy sysadmins (and web developers that don't want to be sysadmins!) the ability to get a functional web dev environment up and running with ease.

Go ahead, give XAMPP a shot!

Trying this... Posting from jlime

Thanks to a tip from a jlime forum denizen, I found out that an older kernel would work better on my Jornada 720. Suspend works, WiFi works, even the Torsmo status app works better. Minimo didn't like Blogger, but the Dillo browser seems to be working albeit in a really minimalistic way like you'd expect in a phone's browser.

In short, this is actually a completely functional networked Linux PDA right now. I'll keep this around and do some periodic reviews as I further use this platform.

UNIX variants on HP Jornada Palmtops

We covered this a bit at the 2600 meeting last night. I don't have a lot of time to go into detail, but here's a quick breakdown.

Asmodian X got me hooked on Windows CE Palmtops back in late 1997. I picked up a floor model HP 300LX for cheap, and actually used it as my main computer (including Dialup BBS, Telnet, Mail, and web browsing) for quite a while. It was more than sufficient for typing my papers for class and interfacing with the UNIX servers. Asmo also had a Casio Cassiopeia running CE, so we tinkered with this stuff a LOT back in the day.

Later, at DefCon 6, we'd run into a guy with an HP 620LX. That thing had a full color screen and a significant boost in memory, not to mention sound recording ability. This all sounds cheesy now, but it blew away the devices we had with their four or 16-color greyscale screens.

As time has progressed, I've also acquired an HP 320LX (same as 300LX but with a backlit screen and more RAM), a Jornada 680e (Refurbished Dutch Railways model) and a Jornada 720.

The HP300's are currently packed away somewhere, but the Jornadas are alive and well.

I was considering NetBSD and Linux for this project, but I found out that the NetBSD project for these pretty much died once they could say "it boots!" You have to use a serial cable for the console. In other words, it's useless until someone ports wscons and some device drivers. So, I chose JLime Linux, which is still in active development -- the kernel build on my 720 (Mongo branch) is less than two weeks old!

To install JLime, you need a CF card that's at least 128MB. You create 3 partitions:

1. FAT partition usable from within Windows CE
2. ext2 partition for Linux to run from
3. Swap partition for virtual memory

You copy the bootloader, boot configuration file and zImage (kernel, etc) to the FAT partition, and then uncompress the jLime userland onto the ext2 partition. Since the files were compressed with bzip2 and BSD's tar utility doesn't know what to do with that, I had to uncompress it before using tar. Make sure you run tar as root (or with sudo) and with "xpf" or "xvpf" to retain the file permissions and ownership of the userland image.

Once you insert the card into the PDA and run the boot loader, all of the PDA's memory will be completely wiped, so all files and data on it will be lost. Windows CE stays in ROM so when you reboot, Windows CE will be back in initial setup mode.

I actually put the boot loaders and zimages for both the J680e and the J720 on the FAT partition, created two different ext2 partitions, and left one shared swap partition on my 2GB CF card. Had I been thinking, I would have made a third ext2 for a shared home directory between the two PDAs.

Right now, here's the status of them:
Jornada 680 running jLime (Donkey):

• Boots Linux, loads fine.
• The keymap is completely trashed (dutch keyboard layout) so I can't login.
  
• Apparently, the J680 can "suspend" while running jLime.
  

Jornada 720 running jLime (Mongo)

• Boots Linux
• Runs X with IceWM
• Various X Apps work fine (MiniMO Browser, aterm, etc)
• Recognizes PCMCIA Ethernet and 802.11b/g wireless cards
• Can't seem to use the network, even when configured properly (dhcp doesn't get an address, wireless cards can't associate to open, unencrypted networks, etc)
• Cannot go into suspend mode properly. The backlight stays on, limiting battery life.
• After halting, the PDA can't reboot without a hard reset (removal of main and backup battery at the same time)

So, it looks like jLime has a little ways to go yet, but it's a functional UNIX environment, at least on my Jornada 720. I just wish I could get the networking piece to work properly. I could almost live without a suspend mode, since many of my other laptops don't particularly like to suspend, either.

April Kansas City 2600 Meeting Sneak Preview

jlime Linux on the HP Jornada 720 Handheld/PC

This and a bunch of other stuff at the KC 2600 meeting.

Tonight (Friday, April 4 2008)
Oak Park Mall Food Court (Northeast entrance)
SE Corner of 95th and Quivira in Overland Park, KS
Starts at 5:00PM. Look for geeks with laptops.

Upgrade your mobo BIOS without Windows or DOS.

Sometimes you find a nifty piece of hardware that you just can't let go into disuse. This time around it was a Tualatin Pentium 3-S 1266MHz CPU new-old stock, new-in-box. I got it some time ago to upgrade a PC for family that it turns out just upgraded the whole system instead. Thus it sat around in the box until I ran across a mobo to drop it in. Recently I found a system at my favorite shopping destination (Surplus Exchange) that had a Tualatin capable mobo; the DFI CM33-TL just so happens to max out a the 1.26Ghz P3-S I already had. Even nicer is that it is the Rev C board which with the newer BIOS updates can boot from USB and can do 48-bit ATA addressing. Alas, no AGP slot. So why all the love for an old P3 server chip? The later P3-S could outperform the early P4 chips and use half the wattage! So what do we do when all that we have to boot the system with is a non-Microsoft OS and most BIOS update utilities run in Windows, or use disk creation software the runs in Windows/DOS? Luckily it seems that is is possible to update some mobos without having to resort to using an unwanted OS. DFI has made the CM33-TL able to boot from a floppy or run a program under Windows to flash the BIOS - or enter an update mode that simply reads the flash utility and BIOS file from a floppy. It turns out that it is a good thing they enabled all three. Under a fairly standard Ubuntu Linux install I was able create a floppy the the DFI board could update from by combining the BIOS update features in a way DFI didn't document.

Several steps that worked for me:
1. Nab the BIOS update of choice for your mobo & revision. Be sure your file is correct - close doesn't cut it with a BIOS. It's either an exact match or something won't work right. In my case I could nab the smaller download intended for a Windows-based update utility.
2. Extract the .zip file containing the utility and BIOS image. Many of the .exe files manufacturers supply are programs meant to run under DOS or a DOS shell to create a disk image. By having the .zip we can get around that.
3. Copy the extracted files to a freshly formatted and tested floppy (basic FAT12/MS-DOS format is fine). Having a good floppy is very key to a successful flash. GIGO is an important point to consider when doing something that can brick a system.
4. Reboot the system and be ready to press the BIOS flash key(s) when prompted. On the CM33-TL you press Alt-F2 just after the RAM test and floppy seek.
5. The BIOS will then enter the flash update mode and read the floppy. If it determines the BIOS image is compatible it will begin to flash it to the BIOS chip.
6. Once it's done enter the BIOS setup and "Load Safe Defaults". This will let the BIOS set any settings that might cause the system to fail to boot. Go though the menus and set things as you need.
7. Test boot to be sure it works as before. Test boot again using the new features and marvel at the sudden uses that have opened up.

I had been concerned about having to make a bootable floppy for the update but the BIOS option to enter the update mode does not need a fully bootable floppy to operate.

With a system like this it is possible to operate a NAS system with large drives on a chip that boots from a USB thumb drive, operate on older, cheap RAM and uses little power. Having a system that boots from USB allows you to configure the server to spin down drives that are idle and save more power; an OS on a USB device will not need to spin up the main/RAID drives to write logs, etc. Smart choices of hardware can make a cobbled together server operate more efficiently.

Sysadmin Sunday: A slightly more advanced intro to SUDO

Sudo is a neat utility which allows a computer to be administrated with out passing around the root password.

This article is meant for folks who are a step beyond the "Linux flavor of the week syndrome" and are needing to delegate responsibilities to other people with out letting the cat out of the bag. This document does not cover user and group restrictions only the run as super user aspect is covered.

1. Introduction
2. Basic demonstration
3. Configuration
4. Administrator Sluggo says ...
5. Informative resources
===========================================================
1 - Introduction
So here we are, we got a pile of people to take care of stuff for you but we need to limit each persons access to only what they need to do.

2 - Basic Demonstration
Most installations restrict sudo so it is un-useble. An admin needs to run the "visudo" command to add users or groups into sudo in order for it to allow some one to run an application as another user like root or some other powerful system user.

Sudo is similar in function to the switch user or "su" command. The difference is that where su is a dumb animal and asks for the target users password, sudo is configurable to authenticate to different account privileges in different ways and provides detailed logging and control to what applications can be executed with that users permissions.

One of the default setups which people choose is to allow all users in the wheel account to run as root privileges on all applications on all hosts. This is not an ideal setup obviously because any one in the wheel group becomes like root.

But lets say I am a backup administrator who for some reason needs root access to the whole machine.

somehost$ sudo tar -cvf /dev/tapedevice0 /

Then it will prompt me for my password (not roots) then execute tar with root privileges. With the same setup we could just as easily do this:

somehost$ sudo /bin/sh

It will then prompt me for my password, then give me a shell with root privileges.
This behavior can be changed of course which is the next topic.

3 - Configuration
The configuration file for sudo is typically in /etc/sudoers. But typically we would use the "visudo" command to configure the file.

USER or USER_ALIAS HOST or HOST_ALIAS = (TARGET USER OR USER_ALIAS) COMMAND OR COMMAND_LIST

Example:

Defaults!PAGERS        noexec //prevents shell escapes in pager programs
User_Alias     ADMLIST = asmodianx
User_Alias     USERLIST = will, wendy, wim
Runas_Alias    TARGETLIST = root, operator
Host_Alias     HOSTLIST = HOST1,HOST2
Cmnd_Alias     PROGRAMLIST = /usr/bin/sh, /usr/bin/csh, \
                    /usr/local/bin/tcsh, /usr/bin/rsh, \
                    /usr/bin/ksh, /usr/local/bin/zsh
Cmnd_Alias     PAGERS = /usr/bin/more, /usr/bin/pg, /usr/bin/less
#-------------------
USERLIST     HOSTLIST=(TARGETLIST)PAGERS
ADMLIST      HOSTLIST=(TARGETLIST)PROGRAMLSIT

In this example we prevent shell escapes in the pager programs (less, more ...etc).
We then allow access to the shells for the admin user. Sudo is also network aware
PAM modules should work seamlessly but LDAP groups look like local groups I believe.
NIS+ networks or using rsh is where the network aware settings come into play.

4 - Administrator Sluggo says ...
Some Linux distributions have some silly concepts when it comes to default sudo configurations. SUSE for some reason thinks that sudo is some kind of replacement for su, so it enables sudo commands for all members of the "users" group only if they know the target users password. Assigning root shells is generally a bad thing too but this depends heavily on your management style.

5 - Informative resources:
http://www.wlug.org.nz/SudoHowto
http://www.linuxhelp.net/guides/sudo/
http://www.gratisoft.us/sudo/man/sudo.html

Sysadmin Sunday: Logical Volume Management on Linux

I'm starting a series of articles that are handy for system administrators -- mostly Linux, BSD, AIX, and Solaris. I'll be releasing the series over the next few weeks, and I've aptly named the series "Sysadmin Sunday." The first topic is on setting up and using the built-in logical volume manager in Linux. This is going to be a long article, so I apologize in advance. Let's dive in!

Introduction
LVM2 is the new Logical Volume Manager for the Linux 2.6 kernel. Logical volume management has been a key part of enterprise UNIX installations (such as AIX) for quite a while, but is a relatively new feature to Linux. LVM1 had some severe limitations. Many of them have been overcome with LVM2, but a few key features found in other operating systems are still missing. That said, Linux is really coming into its own these days, and this is a major step in the right direction. Once you've mastered the concepts of logical volume management, you will be able to understand it on other platforms as well, and learn it quickly.


Benefits of LVM
Logical volume management gives you a lot more flexibility in how you utilize storage on a system. For instance, If you're unsure how much space to allocate for various partitions on a new server, LVM provides a way to simply change the sizes of partitions, even if it means that a single logical partition is spread out across multiple hard disks. This is useful for casual LAMP server systems as well as large enterprise hosting installations.

There are two basic ways to set up a new system with LVM. The first philosophy is to simply partition the system the way that you would without an LVM. If the storage needs change later, a partition with excessive free space can be shrunken so that space can be added to the partition that needs it. The other philosophy is to partition the space to meet the immediate needs of the system. Only allocate what you know you will need, and leave room to grow. It's no problem if you need more room for software, databases, file server storage, or website content.

Hardware/Software Configuration
My staging environment for this project is an old Dell Optiplex GX150 Desktop which I've named "silence." It's got a 20GB EIDE drive and a plain old CD-ROM drive. I added a pair of 80GB EIDE drives to demonstrate how LVM handles physical volumes.

I'm using Ubuntu 7.10 Gutsy Gibbon Server Edition. During installation, I chose to manually partition the 20GB drive. You could simply choose the "Use full disk and configure LVM (guided)" installation option.

The reason I did a manual partition was to make an LVM setup that has room to grow. This is clearly the second philosophy. Partitioning is set up as follows, if you're interested:

• 128MB was allocated as /boot (ext3)
• 256MB was allocated as swap
• The remaining 19GB or so was set up as one big LVM Physical volume
• Within the LVM, I allocated 4GB as the root partition.
• Within the LVM, I allocated 7GB as the home partition.

LVM structure
Each system can have one or more volume groups. The volume groups hold physical volumes and logical volumes. Physical volumes are simply disk space which has been allocated for LVM use. Logical volumes are actual formatted space that the system can use. One could say that physical volumes provide space to the volume group, and logical volumes are partitions of the whole volume group.


LVM Command-line tools
There are four sets of commands for using the LVM system. First, there are general LVM (lvm*) commands. Next, there are commands for manipulating the volume groups (vg*). Another set for managing the physical volumes (pv*). Then, a final set for logical volumes (lv*, minus the lvm commands, of course).


The lvm command is an interactive command environment which can be used instead of calling all of the other programs from within your shell. I usually launch lvm from sudo, then I don't need to use sudo prior to each LVM command, nor do I need to login as root. Also, typing "help" within lvm lists all of the LVM commands and a short description, which can come in handy if you're just getting started. Preceding each command with help gives you access to a quick help description for each command.


Let's see what the LVM configuration looks like:

axon@silence:~$ sudo lvm

lvm> vgs
VG         #PV #LV #SN Attr   VSize  VFree
silence_vg   1   2   0 wz--n- 18.29G 7.23G

lvm> pvs
PV         VG         Fmt  Attr PSize  PFree
/dev/sda3  silence_vg lvm2 a-   18.29G 7.23G

lvm> lvs
LV           VG         Attr   LSize Origin Snap%  Move Log Copy%
silence-home silence_vg -wi-ao 7.05G                            
silence-root silence_vg -wi-ao 4.00G                  

As you can see, I have about 7GB free on my 18GB volume group The other drives in my system haven't been partitioned for use as LVM physical volumes yet, so they don't show up with the "pvs" commands.


Preparing new drives for LVM
After installing new hard drives, you should first partition them with type 8E (Linux LVM)

I'm going to use cfdisk to create lvm partitions on the two drives (/dev/sdb and /dev/sdc). There's an animation below to help you with partitioning if you need it.

axon@silence:~$ sudo cfdisk /dev/sdb
axon@silence:~$ sudo cfdisk /dev/sdc

Once the drives have been partitioned as LVM, you can initialize them with pvcreate.

axon@silence:~$ sudo lvm
lvm> pvcreate /dev/sdb1
 Physical volume "/dev/sdb1" successfully created

lvm> pvcreate /dev/sdc1
 Physical volume "/dev/sdc1" successfully created

lvm> pvs
 PV         VG         Fmt  Attr PSize  PFree
 /dev/sda3  silence_vg lvm2 a-   18.29G  7.23G
 /dev/sdb1             lvm2 --   74.53G 74.53G
 /dev/sdc1             lvm2 --   74.50G 74.50G

Now there are now three physical volumes present. The 80GB drives show up as only having 74GB free because a certain percentage of blocks are set aside to use in the place of any bad sectors that might be found. I haven't added the new drives to a volume group yet.

Creating a new volume group and logical volume
I'm going to create a new volume group for my web root files, and add sdb1 to it. This way, I can easily export the web data, take snapshots for backups, and all the other great things that LVM affords a sysadmin. Once I add the webroot_vg, I'll create a 20GB logical volume and format it with ext3. This should leave about 60GB free on the new volume group.

lvm> vgcreate webroot_vg /dev/sdb1
 Volume group "webroot_vg" successfully created

lvm> lvcreate --size 20GB -n webroot webroot_vg
 Logical volume "webroot" created

axon@silence:~$ sudo mkfs.ext3 /dev/webroot_vg/webroot
mke2fs 1.40.2 (12-Jul-2007)
... output truncated ...

Once that's complete, I have to create a place to mount it, and tell the system to mount it on boot up.

axon@silence:~$ sudo mkdir /webroot
axon@silence:~$ sudo vi /etc/fstab

I added the following line to fstab with vi:

/dev/webroot_vg/webroot   /webroot  ext3  defaults,errors=remount-ro  0  1

I mounted it.

axon@silence:~$ sudo mount /webroot
axon@silence:~$ df -h

Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/silence_vg-silence--root
                     4.0G  504M  3.3G  14% /
varrun                 61M   40K   61M   1% /var/run
varlock                61M     0   61M   0% /var/lock
udev                   61M   80K   61M   1% /dev
devshm                 61M     0   61M   0% /dev/shm
/dev/sda1             122M   24M   93M  21% /boot
/dev/mapper/silence_vg-silence--home
                     7.0G  138M  6.6G   3% /home
/dev/mapper/webroot_vg-webroot
                      20G  173M   19G   1% /webroot

Resizing logical volumes
So, what happens when the space starts to get a little cramped? Add more space and resize it!

Unfortunately, this isn't something that can be done while the filesystem is mounted. You'd have to stop the web server, umount the directory, and do the resizing stuff. Here we go.

axon@silence:~$ df -h /webroot/
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/webroot_vg-webroot
                       20G   19G  390M  98% /webroot

Ooops! 98% full! I'll umount it and use lvresize to add another 10GB from the webroot_vg to it.

axon@silence:~$ sudo umount /webroot/

axon@silence:~$ sudo lvresize -L +10G /dev/webroot_vg/webroot
  Extending logical volume webroot to 30.00 GB
  Logical volume webroot successfully resized

After that, we need to tell the filesystem about it with resize2fs. It's a good idea to run fsck first, though, to make sure that the filesystem is in a good, clean state before we go messing with stuff.

axon@silence:~$ sudo fsck -f /dev/webroot_vg/webroot
fsck 1.40.2 (12-Jul-2007)
e2fsck 1.40.2 (12-Jul-2007)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/webroot_vg/webroot: 14/2621440 files (7.1% non-contiguous), 4880972/5242880 blocks

axon@silence:~$ sudo resize2fs /dev/webroot_vg/webroot
resize2fs 1.40.2 (12-Jul-2007)
Resizing the filesystem on /dev/webroot_vg/webroot to 7864320 (4k) blocks.
The filesystem on /dev/webroot_vg/webroot is now 7864320 blocks long.

Voila! 30 Gigs.

axon@silence:~$ sudo mount /webroot/
axon@silence:~$ df -h /webroot/
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/webroot_vg-webroot
                       30G   19G  9.8G  66% /webroot

Similarly, if you had a reason to need to borrow space from an existing logical volume, lvresize and resize2fs would work for shrinking a filesystem, too.

Spanning multiple physical volumes with one logical volume
Let's try something different. There's about 7GB of free space on the main volume group, and there's still one 74GB physical volume in this system that we haven't done anything with yet. I'm going to go ahead and add it to silence_vg with vgextend.

axon@silence:~$ sudo vgextend silence_vg /dev/sdc1
  Volume group "silence_vg" successfully extended

Taking a look at silence_vg, we can see that there is now 81GB of free space in the volume group.

axon@silence:~$ sudo vgs silence_vg
  VG         #PV #LV #SN Attr   VSize  VFree
  silence_vg   2   2   0 wz--n- 92.79G 81.73G

I'll create another logical volume and take up the entire remaining amount of free space in silence_vg. Then, I'll put a filesystem on it, of course.

axon@silence:~$ sudo lvcreate -l100%FREE -n test-lv /dev/silence_vg
  Logical volume "test-lv" created

axon@silence:~$ sudo lvs
  LV           VG         Attr   LSize  Origin Snap%  Move Log Copy%
  silence-home silence_vg -wi-ao  7.05G                             
  silence-root silence_vg -wi-ao  4.00G                             
  test-lv      silence_vg -wi-a- 81.73G                             
  webroot      webroot_vg -wi-ao 30.00G   

axon@silence:~$ sudo mkfs.ext3 /dev/silence_vg/test-lv
mke2fs 1.40.2 (12-Jul-2007)
... output truncated ...                    

A quick look shows that I've created a filesystem that is actually larger than any of the drives in the system!

axon@silence:~$ sudo mount /dev/silence_vg/test-lv /backup

axon@silence:~$ df -h /backup
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/silence_vg-test--lv
                       81G  184M   77G   1% /backup

Snapshots and backups
Snapshots are temporary time-frozen views of a logical volume. They appear as a copy of the logical volume, but don't change. Instead, you allocate space for any changes that will happen on the live volume, so that there's space to hold copies of the changed blocks as they were at the time of the snapshot. This is great for taking hot backups of data that is subject to frequent changes, without a service interruption. Passing the -s flag to lvcreate tells the LVM system that you're creating a snapshot. In this case, after the -n [name] option, you tell it which LV to create a copy of. Simple as that.

While a snapshot is active, the system needs to make two writes for every block it changes. This creates a slight performance impact. Also, if the space you allocate for tracking changes gets filled up, there's a good chance that your snapshot will fail, automatically un-mount itself, or have unreliable data within it. For this reason, I created a backup script that automatically creates and mounts the snapshot, gets a backup, then gets rid of the snapshot. I've pasted it below, although it's just a mock-up and I'd probably use something a little more resilient than a simple tar command in real life.

#!/bin/sh
lvcreate -L1G -s -n webroot-backup /dev/webroot_vg/webroot
mount /dev/webroot_vg/webroot-backup /snaps/webroot/
cd /snaps/
tar czf /backup/`date +%Y%m%d`-webroot-backup.tar.gz webroot
umount /snaps/webroot
lvremove -f /dev/webroot_vg/webroot-backup

Closing
Hopefully, this gives you enough to start with when it comes to configuring and managing LVMs on Linux.

ArsTechnica reviews Ubuntu Gutsy Gibbon

Finally, there's a really good technical overview of Gutsy, thanks to Ryan at Ars. Read on to get the skinny on the next iteration of the so-called perfect desktop Linux distribution. 

http://arstechnica.com/reviews/os/ubuntu-gutsy-gibbon-review.ars

Operating systems out the wazoo!

In a matter of two weeks, we've seen a plethora of new OS releases:

• Ubuntu Linux 7.10 (Gutsy Gibbon) (Oct 18th, 2007)
• MacOS X 10.5 (Leopard) (Oct 26th, 2007)
• OpenBSD 4.2 (Nov 1, 2007)

I know that I am currently playing with all three:

I'm currently working with a fresh, clean install of Gutsy Server, building an end-all, be-all shared host for a client of mine who wishes to give dozens of end-users their own web space and e-mail domains. I haven't messed with Gutsy on the desktop yet. In due time.

I did an in-place upgrade to Leopard on my MacBook, and it's everything I expected and then some. There are a few minor annoyances, but I'll chalk them up to Apple making an attempt to match and/or exceed Vista's user-interface flair. Unfortunately, I feel that the UI changes in Leopard traded friendliness and clarity for sex appeal. It looks slick, but the graphical changes are skin deep. Functionally, Leopard is still lean and mean. I don't feel like it took a performance hit, and there are boat-loads of new feaures - some of them long overdue (like Spaces, and QuickLook which I'm already a fan of). Things I'm looking forward to testing out: ZFS Support (which requires a developer download to fully implement on Desktop Leopard), Time Machine, and the new "Firewall."

I also did an in-place upgrade to OpenBSD on the virtual machine that I use most often. At first glance, it's the same deal as usual. More hardware support, more robust drivers for certain devices, and some new functionality. I haven't gotten to test it yet, but I'm eager to see the new features in pkg_add, which has never, ever worked the way I would like -- so much so that I actually wrote (and released) a set of scripts to make installing software a breeze in OpenBSD. Finally, I'm interested in seeing how sensorsd works in its new zero-configuration mode on my 1U servers, which have always given OpenBSD's sensorsd some trouble.

I'm sure that HiR will revisit some of these in more detail after really giving them a good shake down.

If you're in or around Kansas City, come join us at the 2600 meeting tonight, Friday October 2nd, 2007 in the Food Court at Oak Park Mall - half a mile east of I-35 on 95th street. The "Official" start time is 5:00PM, but people generally show up as their schedule allows. Look for laptops. That will be us.

Linux: Ready only for the geek desktop

I do almost everything within either OpenBSD, Solaris or Mac OS X. All of them required me to install quite a few extra pieces of software to work just the way I like, but at the end of the day, they're great for the things I do, with some exceptions noted in Solaris. I spend the majority of my time doing web stuff (surfing, forums, blogging), listening to music, writing e-mail, word processing, performing systems administration, and tinkering with encryption and information security. Occasionally, I may goof around with my own music or graphical art. Solaris lacks easily-installed free or bundled graphics, MIDI, and audio editing software.

Enter Linux. Linux is a pretty broad brush to be painting with these days. Linux is a kernel. It's also a highly generalized term for any operating environment with Linux at its core. The end result is quite confusing. As part of my job, I take care of a bunch of Red Hat Enterprise Linux servers. I've been familiar with Red Hat for quite some time. While I don't particularly like how Red Hat approaches certain things, I am quite good at installing, patching, managing, and tweaking Red Hat Linux servers simply because I've been doing it for so long. When I went to play with a totally different flavor of Linux on a spare server at home, however, my first instinct to use the command-line for everything was met with a few problems. Primarily, many of the tools and programs that Red Hat provides me with are nowhere to be found. Only because of my familiarity with Linux and UNIX flavors in general (okay, and my ability to read documentation) was I able to figure out how certain things were set up. For those who care, it was ArchLinux, but I had similar issues with SME Server as well, despite being loosely derived Red Hat Enterprise Linux.

Right now, the big push in the Linux world is getting Linux onto the desktop. Linux for everyone. Break free from your commercial operating system hell! Linux is here to save the day! Ubuntu is the big name that gets thrown around most often. Self-described as "Linux for human beings", Ubuntu aims to be the final answer to the Linux desktop quandary. After trying Ubuntu Desktop, Ubuntu Server, and Kubuntu Desktop, I can say that "Linux" has come quite a way in its quest for desktop domination.

Ubuntu Desktop is based on the Gnome desktop environment. Asmodian X pointed out to me that Gnome feels an awful lot like Mac OS 9, and I wouldn't have quoted him on that unless I agreed. Part of the clunky feel is the fact that Linux is still bound by the X Window System. Essentially, all graphics go through a network or local socket. Windows and MacOS X don't suffer the same fate, and their interfaces simply feel more responsive. I can deal with a sluggish display, though. There are bigger fish to fry. All flavors of Ubuntu install quickly and ask a very minimal set of questions during installation. As long as the hardware is supported, pretty much anyone can get any of the Ubuntu flavors installed in minutes.

Ubuntu server is everything you'd expect in an open source LAMP server distribution that's released by a company that believes in ease-of-installation. Much like Ubuntu Desktop, only a small set of options are available during installation. The end result is a server distro that is neither lean and mean, nor bloated. It's pretty damned generic, and up to the user to install and configure what needs to be installed if anything more than a basic web application and database server is desired.

Kubuntu Desktop replaces Gnome with the K Desktop Environment (KDE) and a different set of bundled applications -- for the most part, the KDE-based apps are chosen over the competing software packages where available. Konqueror is the default web browser as opposed to Firefox. Kontact and Kopete handle mail/scheduling and Instant messaging respectively. The list goes on and on. If I had to compare Gnome to MacOS Classic, I'd have to say that on a user interface level, KDE feels a bit like Windows Vista with most of the snazzy features turned off, except a little more "Fisher Price." It kind of feels like a toy, but it gets the job done nicely.

Keep in mind that my impression of the two desktop environments is based only on Ubuntu. I haven't used KDE or Gnome prior to this in several years. Right now, I'd say I favor KDE over Gnome, at least in the configurations provided by Canonical (the company behind Ubuntu). There are other variants of Ubuntu which I have not yet tried, so they aren't being reviewed here.

After you get one of the desktop flavors of Ubuntu up and running, keeping the system secure and up-to-date is a breeze. The system checks for upgraded packages that are available for download, and alerts you to their presence. It's easier to keep Ubuntu up-to-date than it is to do the same on Windows. It really is that easy. Installing other software packages can be a breeze as well. Ubuntu provides a graphical application installer that lets you simply choose programs from a list or search through the list for what you want. You simply select the programs you want to install, then install them. The system handles all the downloading and installation procedures on its own, including any other packages that are required by the software you selected.

BSD has been doing package management like this for years without the graphical installation wizard. You still need to know what you want, and have to look through the list manually. Ubuntu is based on the Debian package system, and Debian has also had similar functionality for many years. This stuff isn't new, but combined with the other aspects of Ubuntu, it makes for a system that's pretty user-friendly.

• Installation is a breeze.
• Applications that you need to get going are already installed by default
• Patching and upgrading software is automated.
• Installing new software is as easy as picking it from a list.

Almost anyone can install and use Ubuntu without much of a fuss. What more could you ask for? Quite a bit, actually. Compared to Windows or Mac OS X (still the two heaviest hitters in the desktop operating system market), all Linux flavors are left wanting. Configuration of anything but the most rudimentary options requires the use of the command-line, which is not an environment that many people are comfortable in. For me? I live and die by the CLI and don't mind it one bit. If there's a software package that you read about for Linux and it's not on the list of stuff that Ubuntu provides, then there's no easy way to install it. Someone like me could download and unpack it, and compile it if needed. Most people are used to double-clicking on the installer or dragging the application (seemingly one file) to their hard drive. Don't get me started on the difficulty of installing certain drivers under Ubuntu.

The other advent that the Linux desktop has brought to the table is "Live" distributions. A Live distribution is an operating environment that boots from removable media such as a CD-ROM or Flash drive, providing an instantly functional system that doesn't rely on a hard drive to operate. Ubuntu and Kubuntu Desktop installation CDs initially launch in this mode. You truly get to try it before you install it. Things tend to load very slowly from CD, so the whole operating system seems very sluggish when run this way.

There are dozens of popular Live distributions that you could check out. Back|Track is my favorite so far: for hackers, geeks, auditors, and security professionals alike. Back|Track, is the end result of Whax and Auditor joining forces. Upon booting, you get a clean, functional desktop platform from which to launch any number of tests and exploits.

Truly, Ubuntu is only good for end users who are happy using it pretty much just as it comes from a default installation. The Live version is sluggish and not recommended as a replacement for Windows - a preview if you will. Other Live distos are great for tinkerers and nerds. For geeks and hackers, a full install of Debian or ArchLinux would be considerably more flexible than Ubuntu if you wish to stick with the Linux kernel.

In closing, I'll say that the biggest hurdle remaining for Linux to conquer on the way to end-user desktops is the fact that the command-line is still not optional despite the best efforts of the Linux community. A command-line should only be required as a last-ditch interface to the operating system in order to recover from some earth-shattering catastrophic failure. Windows has been to this point for years. OS X has as well. For some reason, Linux is lollygagging. It would also help if everyone could just agree on one package distribution model and stick with it. So far, I think Debian's system holds the most promise for the Desktop and enterprise workstations.