Wow, it’s been a long time since I blogged anything. I’ve been busy with professional studies and a job change, so those things, along with the holidays and back-to-back colds. And wifey has been chugging along with her book and asked if I was still blogging, so I guess that spurred me to jump back in. But I have nothing technical prepared, so just this little post so my hordes 
of readers don’t think I’ve joined the legionnaires.
I’m still here!
Logical Volume Expansion With Linux LVM
Sometimes we just run out of space in filesystems. Whether due to lack of understanding of application storage needs, poor planning or we just need extra space for a development effort, we find it necessary to add disk. Virtualization gives us the ability to quickly provision new virtual disks that behave identically to physical ones. This, in conjunction with the flexibility of Linux Logical Volume Management (LVM), we can easily grow volume groups, logical volumes and filesystems. It also makes it easy to practice the techniques before provisioning additional storage in customer production environments. So let’s add a disk and grow the root filesystem in a Sun VirtualBox / Fedora 10 environment.
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Propagate SSH keys across a Linux Cluster
If you build and manage Linux clusters, you need to easily SSH and SCP among all the nodes without entering a password each time. Some cluster software requires that ability, so it can move files and software and run commands among all the members. Oracle RAC is an example. The Clusterware Verification Utility will fail the user equivalence test without a proper SSH setup.
The usual method for accomplishing this SSH setup is to (simplified for illustration):
On node 1
On node 2
On node n
.
.
.
This is silly. Since I try to eliminate as much repetition as possible in order to decrease build time, I scripted something up that you still run on each node, but it automates the rest.
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It’s System Administrator Appreciation Day
And I’m a tad bit late posting about it. My wife does not agree that she should buy me a shiny new sports car as a present. I may get a beer greeting at the door when I get home. Good enough, since she’s cute.
Mini-ITX Appliance Update 2
So late last week I received the fan replacement I ordered. This one is a little more than half the noise volume of the original: 25 dBA vs. 42 dBA. I can’t hear this fan over my desktop computer, which has loud fans all over the place. I built that one for gaming about six years ago, and it was a bit unsettling to have this slick little new device be twice as loud.
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Mini-ITX Appliance Update
I have finally gotten around to writing about progress on the Mini-ITX appliance. It’s built, has Fedora 11 on it, and I have a couple hardware related changes to make. One, is that the Mainboard shipped with a rather loud CPU fan. So I looked for a 40mm 4-pin fan with no luck, so I settled for the quietest 3-pin I could find. The other is that I neglected to get an antenna and pigtail for the wireless. It’s an Intel 4965 AGN Mini-PCI express adapter, and I had a b**** of a time getting it to associate with the wireless AP. Once I managed to get it to reliably associate using WPA_supplicant, I discovered that it would not transfer faster than 350Kbps. I should be getting 54Mbps, since the AP is a 2.4GHz G Linksys. AP web GUI (Tomato firmware) showed link quality of ~7 to ~12. It didn’t occur to me that I needed to have the antenna. I’m dense sometimes. So I’m waiting on shipment of those to items.
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Write a UDEV rule to automatically back up your USB thumb drive when its plugged in
Have you ever wanted to run an external program when your USB thumb drive is plugged in? For example, it could be handy to automatically back up its contents to the local hard drive. This will save your butt in case you do something foolish and delete everything on it. (I’ve done this). So here’s a simple example to get you started.
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Mini-ITX Storage Appliance
So I haven’t posted in a while. But I am working on something that I hope takes off. It’s a NAS device that I’m building using a Mini-ITX board, a notebook computer CPU, notebook drives and memory and a very small Mini-ITX enclosure. This actually has a couple use cases – the NAS appliance, but also a very small virtualization platform too. Perhaps by booting ESXi from a USB drive that I can have mounted on the board and closed up in the enclosure. I was really searching for higher capacity drives, but the best I could do with 2.5″ SATA is 500GB. So I’m left debating RAID 1 with only 500GB available but with needed redundancy, or a stripe set with a very fast 1TB capacity and no redundancy. It’s all about trade-offs I suppose.
Some components were delivered today! So I have sitting here in front of me, the main board, CPU, Memory and the two 500GB SATA drives. 
I will most likely be able to start the build by the weekend. I’m waiting on the enclosure, the Pico PSU and the PCIe mini wireless adapter. I want a wireless option for this, but I also chose a main board that has 2 GbE interfaces for bonding options. I chose a robust board with RAID and dual Gb NICS plus a dual core CPU, which is probably overkill for a home NAS device. But it will rock. I would like to get this built, see how it all goes together, get a small footprint Linux on it and test and eventually use it for our home data. But the next step after this project is to see if I can build one with less expensive components but have comparable performance and robustness. More is to come…
Going to EMC World in Orlando, FL
I’m excited! My employer is flying me to Orlando to attend EMC World. The event, which begins Monday the 18th and runs through Thursday the 21st, is where folks like me can catch up on storage and virtualization trends and get some hands on sessions. My focus will be in the Clariion and Symmetrix product lines, Enterprise Flash Drives and Virtualization/Cloud Computing trends. I’m flying wifey-poo in on my own dime, so she can chill at the resort with a pink drink and umbrella while I slave away in sessions and gather convention swag. It’s a tough life, I know!
I’m a Janitor
A good friend once told me that System Administrators are a lot like Janitors. As long as we’re doing our jobs, no one knows we exist. We lurk in the shadows of the data center like trolls. Though I prefer the term “Custodian”, since it conveys the sentiment of being a care taker. Which is really what we are.
