raidtools

raidtools is the traditional package used to manage software arrays. Although the newer mdadm is more feature-rich, raidtools is in wider use throughout the software RAID community. While it’s a bit more complex to manage arrays using raidtools, the package has proved reliable for many years. raidtools has remained at version 0.90 for several years, but the prerelease for version 1.0 of raidtools became available during the course of this writing, although it has not been officially released yet. The new version has some new utilities, including a tool that allows users to generate /etc/raidtab files by querying an active array, which is very useful if you’ve accidentally deleted your /etc/raidtab file. The additions to version 1.0 are covered in this section, but keep in mind that I used a narrowly released beta version during my testing, and that some functionality might have changed since then.

Version 1.0 fixes several known bugs in the 0.90 release of raidtools. raidtools-20010914 (version 0.90.0), in addition to having some minor bugs, was released without a vital utility, raidsetfaulty.This utility is used to manually induce a disk failure and had been included with previous releases. Instead, raidtools-20010914 shipped with a new program named raidhotgenerateerror, whose name makes it look like a replacement for raidsetfaulty. Unfortunately, raidhotgenerateerror does not perform the same function as raidsetfaulty and should not be used as a replacement. raidhotgenerateerror is merely a utility for testing error handling in the md driver. This has caused some confusion among Linux RAID users. Because of these inconsistencies, I advise against using raidtools-20010914. Instead, download and use the previous release raidtools-19990824 from ftp.kernel.org/pub/daemons/raid/alpha. If you are working with a version of raidtools that came installed with your distribution, check to see if you have /sbin/raidsetfaulty on your system. If it doesn’t exist, then it’s likely that you are working with a repackaged version of raidtools-20010914. In that case, I recommend installing the previous version from source, or using a newer version if one is available and tested. The beta version of raidtools-1.0 corrects many of the problems with the raidtools-20010914 release and also contains raidsetfaulty. It likely that raidtools-1.0 will be in wide release by the time this book is in print.

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