[$] A journal for MD/RAID5

RAID5 support in the MD driver has been part of mainline Linux since2.4.0 was released in early 2001. During this time it has been usedwidely by hobbyists and small installations, but there hasbeen little evidence of any impact on the larger or "enterprise"sites. Anecdotal evidence suggests that such sites are usually happier with so-called "hardware RAID" configurations where a purpose-builtcomputer, whether attached by PCI or fibre channel or similar,is dedicated to managing the array.This situation could begin to change with the 4.4 kernel, which brings someenhancements to the MD driver that should make itmore competitive with hardware-RAID controllers.