Adaptec did this for years. The better systems send you an alert and then you hot swap in the new drive and it's very automatic.
HOWEVER you see folk today try to do this with software and it's not that good.
Bob
I have a doubt regarding RAID5 reorganization. Suppose we have a RAID5 group consisting of 6 disks in a storage system. Suppose, one disk (call it d1) is unreachable i.e the disk component does not fail but some component (for example, some network cable) to reach that disk has failed. Although the data in d1 is valid, the data in d1 is inaccessible. In this scenario, will the reorganization will start or some field repairperson will try to repair/replace that component? Replacing a component seems to take less time than reorganization because reorganization is very costly with respect to time . Also, data in d1 is valid (so just repairing that component will make everything fine).

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