On Nov 27, 2009, at 6:19 PM, John R Pierce pierce@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