Starting with Triton platform image 2019-06-05, we introduced a new zpool feature named resilver_defer. This also introduced a new bug, OS-7982, that affects systems running this PI (or newer) and have resilver_defer disabled (which is the default). When a disk is replaced with another on a pool with the resilver_defer feature present, but not enabled, the resilver activity restarts during each spa_sync.
At this time, there are currently two workaround options for this bug.
1. Boot to an older platform image and allow resilvering to complete. This would include all platform images prior to 20190605T231205Z, however, the best option would be to revert to 20190514T174437Z.
2. Preferred method: Upgrade the zpool to enable the resilver_defer feature.
- To upgrade the zpool, run the following command:
zpool upgrade zones
Note: Once you upgrade the zpool, you cannot downgrade it (i.e. you cannot boot the CN to a PI older than 20190605T231205Z). This may prove problematic if a CN needs to be booted from a USB stick that is loaded to run on an older platform image version, therefore the USB stick would need to be updated as well/first.