You should consider temporarily disabling the mirroring capabilities
of the boot drive before you begin upgrading to version 2.1. This allows you
to keep version 1.1 of the SAN File System on one drive while you upgrade
to version 2.1 using the other drive. If you need to restore your version
1.1 boot drive configuration, you can reconfigure your boot drive mirror with
the secondary drive as the “primary mirror device,” and your recently installed
primary drive as the “secondary mirror device.” Otherwise, after you are
satisfied with your upgrade to version 2.1, you can recreate the mirror with
the newly installed primary drive as the “primary mirror device” and the secondary
drive as the “secondary mirror device.”
Note: Keep in mind that while the
mirrored drives are split, the high availability protection provided by the
RAID mirroring is disabled (each drive becomes a single point of failure during
this installation window).