Joe Landman wrote:
Hi Richard:
This I cannot tell you, as I don't have a comprehensive list of what
uses what driver. I'd suggest looking at what drivers it loads for
disks when it comes up. If dmraid comes up *and* enumerates devices,
you have a strong probability that it is a fake-raid. This is not to
say dmraid is bad. Again, its the underlying driver or chipset that
we often run into problems with.
Thanks Joe,
This is a much better picture. I am sure there is no such thing as
"dmraid" coming up when the system I maintain, starts.
Rarely. Fake raid will generally not have any RAM cache or battery
backup capability.
I am also sure, all the storage controllers that I have mentioned have a
Battery and RAM Cache.
In some instances, fake raid is *ok* for OS drives (RAID1 only), if
the bios is smart enough to use it correctly, the underlying fake raid
driver is relatively stable, and you have reasonable disks.
Otherwise, mdadm works great, though you have to patch Redhat/Centos,
as they, by default, use dmraid for the moment. Later model Fedora
appear to have switched to MD raid (after 9 from what I saw, last time
I played with it).
I really appreciate your effort and the time taken to reply back.
Thanks,
Richard
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