Taking a break from the humdrum LZMA stuff, I thought I would share with you what I use in my backpack to keep my systems in line. You may or may not of thought about this, and I hope you find it useful.
First, on the list is CDs. Seeing as though we are faced with hardware all the time as system administrators, specifically with installing and repairing systems, we should be keeping bootable CDs on hand. However, I have found the standard 700 MB disks a bit too bulky. I don't have room, nor the patience, to keep those with me. Instead, I have found that the 50 MB business card CDs are great. They are large enough to create a bootable disk, yet small enough to carry with you without getting in the way. In fact, I carry a Damn Small Linux disk in my wallet all the time, in case I ever need to rescue a system, and it fits nicely. Also, in my wallet, is the latest Debian stable net install ISO, should I ever need to install a Debian GNU/Linux system.
Of course, there are more than just Damn Small Linux and Debian that I carry with me. Ubuntu ships a net install ISO as well, that I have burned to these small disks. A RHEL 5.1 boot ISO, a Fedora 10 ISO, an OpenSUSE 11.0 net install ISO, a CentOS 5.2 ISO, a SLES 10.2 net install ISO, and others. The only problem with these small disks, however, is that if the computer has a slot-loading drive, or the drive is on its side, then they're useless. However, I have a backup for that:
Most modern computers these days support booting from USB. Also, any bootable media, other than optical, tends to read faster. As such, I've made 6 bootable USB sticks, each to boot the same distributions mentioned above. Namely, Damn Small Linux, Debian, Ubuntu, CentOS, RHEL and OpenSUSE. I'll be adding two more that do SLES and Fedora soon. Each stick is 2 GB, and some can do persistence, which gives me the flexibility to save files between sessions. Seeing as though USB thumb drives are getting cheaper and cheaper, 6-2 GB sticks is no big deal for me.
I have 3 external drives that I keep with me always- an 80 GB, 60 GB and 40 GB, each formatted as ext3. On the 80 GB, I've labeled this my "sagedisk", seeing as though I'm a Linux sage by day, and hacker by night. On this disk, there are only the enterprise distributions mentioned above- Ubuntu 8.04 LTS, RHEL 5.1 and SLES 10.2. I've added CentOS 5.2, as Red Hat doesn't allow free downloads of their media like Novell does. I have both 32-bit and 64-bit x86 CPU architectures covered for each distribution. What you'll find on the 80 GB sagedisk, is all the ISOs, should I ever need to burn a physical copy, and that ISO spooled out to a "netinst" directory for rescue media, PXE booting and immediate repository setup. There is a separate "isos" directory, which hold additional ISOs for the community distributions- Fedora, OpenSUSE, Debian, and the intermediate Ubuntu releases.
On the 60 GB external drive, I have a Debian mirror for just the x86 and amd64 architectures for the stable release. I have some extra disk space, which will allow me to do the testing release, as well as add the Sparc architecture, I think. I've debated removing this mirror, though, and instead using it for a more likely mirror that I'll take advantage of, as Debian really doesn't see all that much action, other than my own personal server, in my own life. On the 40 GB external drive, I have the complete Ubuntu binary mirror for x86 and amd64 for the latest release- 8.10.
Lastly, if this isn't enough to cover everything, I have NFS, FTP, rsync, DHCP, Apache, BIND, PXE and TFTP setup, should I need to use it in case of an emergency. I keep a crossover cable with me for times when I need to network boot a computer, and receive an IP address from my laptop. I should mention, that I haven't yet needed to go this route, but the time has been spent to setup the necessary services, should that ever be the case. All ISOs are backed up on the laptop, should the 80 GB disk fail. The mirrors are not backed up, but that might just be forth-coming.
Of course, no tool belt, in my opinion, is complete without cables. I carry with me USB 2.0 cables, of a few different terminal connection varieties, FireWire 400 and FireWire 800. I keep a 3-foot crossover cable with me, and a 6-foot CAT5e cable. I have two female to female CAT5e extenders, should I need that extra length in the room. On top of that, I carry with me a 4-port 802.11g router. It's ultra-compact and lightweight, which makes it suitable for travel. Very useful, should the need arise that I need more distance on networking than I have cable, or for an instant network to test stuff, before making it go live. It's also been great for LAN parties and LUG install fests. 3 blank CDs are carried with me at all times, should I need to burn an ISO. A friend of mine, and former coworker, suggested carrying every USB adapter known to man, but I personally haven't found this useful.
So, there you have it- my list of essential system administrator hardware that you should keep with you in your tool belt. I keep all this in my backpack, with my laptop. It's out of the way, and hardly adds any weight to the load. I am curious what other system administrators out there do with their tool belts. What hardware do you carry with you, and why?