[dm-devel] RAID status, CSMI, and dmRAID

[Juerg Haefliger]

Hi Sandra,

> I’ve recently been researching the issue of obtaining RAID status on Linux
> (using a library or API, not through scripts). I’ve read that CSMI codes can
> be issued (using ioctl() calls) to get RAID status, and from my
> understanding (please correct me if I’m wrong), dmraid doesn’t use CSMI at
> all, and the status is obtained using the metadata on the member drives.
> Does this mean that using CSMI and ioctl is not possible on Linux, or does
> this mean that using CSMI and ioctl is a bad idea on Linux?

CSMI is an interface introduced by Compaq which never gained traction
nor was accepted as an industry standard. It's only supported by the
low-level drivers that manage controllers sold by Compaq/HP. That is
mptlinux, mpt2sas and probably the cciss driver as well which btw has
been replaced by hpsa by now. Stay away from CSMI. It's proprietary
and obsolete.

...Juerg