On Nov 27, 2009, at 6:19 PM, John R Pierce <pierce at hogranch.com> wrote: > Steve Thompson wrote: >> I have a bunch of machines with the LSI 1068E chip, and they _do_ >> work >> fine with the default drivers, for both 5.3 and 5.4 > > > I'm curious... that chip [1] claims RAID 0/1/10/10e support and > implies its hardware raid. Is the integrated RAID support in fact > true raid, such that they present a single SCSI unit per logical > volume, > or is it some form of fake raid which requires driver intervention to > make it play? If it is hardware raid, does the chip/hardware > transparently handle rebuilds? hot sparing? or does it rely on > BIOS > and drivers to implement these features? Most LSI cards are true RAID. > I'd certainly be concerned about the lack of raid cache memory with a > battery back option, and would tend to want to use them as JBOD and > use > the operating system native mdraid instead ... If there is no write-back cache then there is no problem and RAID10 is the best when there is no write-back cache. It may be that the array wasn't defined properly or was offlined. -Rosa