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You may have occasion to edit the contents of an initrd.img file. If so, here is how:

Extract the contents of the image

gunzip < your-initrd.img | cpio -i --make-directories

Now make your edits and then repackage the initrd

find . | cpio -o -H newc | gzip -9 > your-new-initrd.img

Well isnt this a happy day for owners of the Supermicro 8-Port SATA Card AOC-SAT2-MV8. It appears a long standing issue with port timeouts has been fixed.

See the lkml.org mailing list post here

… and the townspeople rejoiced :)

For a long time now I’ve wanted to set up all my mythfrontends to be diskless nodes that boot via PXE using an NFS share as their root filesystem. I finally got around to doing this. I was even able to just migrate my existing installations directly into the PXE boot environment. Here is how I accomplished it…

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Mounting unpartitioned disk image files in Linux is easy. You just execute ‘mount -o loop disk.img /mnt’ right?

Well, if your disk image file happens to contain partitions its a little bit trickier. Here is what you need to do:

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With the forthcoming release of Debian Lenny it happened to be a good time for me to re-evaluate my decision to use one monster RAID6 device to back all my iSCSI targets. I ran a semi-formal test on different disk configurations for software raid and came up with these results…

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The final installment of our coraid adventure and not really much to say other than this: it works! Hotplug support is working as of kernel 2.6.25-git11 and appears to function as it should.

Thanks go to Mark Lord, Marvell Corporation, EMC Corporation and Red Hat, Inc. for the coding magic.

The next phase of this project is choosing AoE or iSCSI. The debate on the relative merits of each protocol continues to rage on the Internet but in my particular case the criteria are pretty simple; which one performs better without causing excessive system load? Just from reading about the two protocols I am already leaning toward iSCSI for the simple fact that I can use all my TCP/IP management tools (routing, NAT, firewalling, etc.) on every iSCSI device. The only (potential) drawback is CPU load on the involved systems since it has to calculate TCP checksums for all those packets. Yes, there are many, many other advantages of one protocol over the other. No, they don’t matter to me in this scenario :-) So here we go!

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You may on occasion have a need to convert .bin firmware images such as those used to flash linksys based devices into .trx formatted images that can be accepted by OpenWRT. Its actually quite easy to do:

dd if=image.bin of=image.trx bs=32 skip=1

That will strip the first 32 bytes off the image, thus making it a valid .trx formatted firmware image file. Neat, huh?

This will be pretty obvious to seasoned *nix admins but it’s possible to tar/gz/bzip files over an ssh connection onto a remote file system. Read on to find out how…

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I have added powerpc to my backports repository in addition to the already included i386 and amd64 archictectures. See this post for more information.

Enjoy!