I am replacing a 4TB disk with a 24 TB one. I always do a pre-clear and read before adding new disk to the array.

But even when the new disk has already been fully precleared/verified as zero, the rebuild still writes the entire 24TB end-to-end, including the portion beyond the original disk size that will reconstruct as zeros.

Can we please add a “skip confirmed-zero regions” / “fast rebuild for larger replacement disks” mode so we get faster rebuilds when upgrading capacity (less wear, less time at degraded protection, less array load).

I assume this would require the rebuild to be done in maintenance mode for safety, but I think its a fair compromise.

Thanks

Edited February 14Feb 14 by tTIKA
typo

In the more general case, Unraid can't make any assumptions about the rest of the array. Safer to rebuild the entire disk than risk the array being out-of-sync.