> Please do not mistake this for me claiming that running this pool with three disks is anything other than a situation to remediate immediately. About a decad

> Please do not mistake this for me claiming that running this pool with three disks is anything other than a situation to remediate immediately. About a decade and a half ago I setup a 48 drive Sun 4540 this way. The OS needed 2 dedicated drives on the first controller so I assigned two neighboring drives on that controller near the intake fans as hot spares. The remaining drives were organized into mirror pairs with each drive on a separate controller. The final root was a concatenation of the pairs. This setup proved to be very robust. Although I left the company when financial troubles pushed the founders into a messy divorce, one of the founders asked me to come back a few years later after they restructured. The 4540 had been moved to a new colo but otherwise ignored because none of the admins knew Solaris or bothered to check the monitoring systems. When I returned I discovered in the time I was away 4 drives had failed but ZFS/smf happily took two of the failed drives offline and replaced them with the spares. The two other failed drives left their respective pools degraded but functional. Replacing the failed drives was easy once they arrived. Although neglected for years, none of the applications or databases that relied on that server ever suffered any downtime from the drive failures.