Nov 03, 2004

Variable Block Support for Linux's dvhtool...

Unlike the IRIX dvhtool, the Linux dvhtool does not support block sizes other than 512. There are cases where a block size larger than 512 is more optimal for performance reasons, and using the dvhtool from Debian can corrupt data in your volume header. I have submitted a patch to Debian to support variable block factors. This implementation is intended for the 1.0.1-5 release according to the package maintainer, but until it is formally released, the patch is available here, which is based on the 1.0.1-4 unstable release.

The patch uses two mechanisms to communicate the block factor to the tool. By not specifying any option, dvhtool will default by using a mechanism similar to blockdev --getss device, and will default to a 512-block size. If you desire to force another block size, such as when you have a device that does not have a detectable block size, the --blocksize (or -b) can be used to specify the block size. The remaining work in the patch is to essentially pass the block size around the library, allowing for maximum flexibility.

Should you have any questions or problems regarding the patch, please let me know.

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