Re: RAID 16?

[Konstantin Olchanski <olchansk@triumf.ca>]

On Thu, Feb 02, 2006 at 03:18:14PM -0600, J. Ryan Earl wrote:
> >
> > Anyone tried [to how-swap] SATA drives yet?
>
> Yes, and it does NOT work yet.  libata does not support hotplugging of 
> harddrives yet: http://linux.yyz.us/sata/features.html

Despite the claims for the opposite, hot-swap SATA does work,
albeit with caveats and depending on chipsets and drivers.

Hot-unplug and hot-plug works for me with 3ware (8506) and LSI
Megaraid (8-port SATA) controllers. Take a drive out, put it back in,
type in a magic controller dependant command to enable it, then
run mdadm --add.

With the SATA Rocketraid 1820 (hptmv.ko) hot-unplug works,
but hot plug does not (hptmv.ko reports "drive plugged in and enabled,
but Linux I/O fails with errors).

With Promise PDC20319 (4-port SATA), I hot swap by "rmmod sata_promise;
remove old disk; connect new disk; modprobe sata_promise". I am sure
this "rmmod" trick works for hot-swapping disks on any SATA controller.

-- 
Konstantin Olchanski
Data Acquisition Systems: The Bytes Must Flow!
Email: olchansk-at-triumf-dot-ca
Snail mail: 4004 Wesbrook Mall, TRIUMF, Vancouver, B.C., V6T 2A3, Canada