I am wondering what situations will result in degraded pool/vdev state when a device is removed (and not replaced)? These are the three devices I’m wondering about:
1) SLOG
2) L2ARC
3) A mirrored drive (assuming no RAIDZ at all, just multiple (3 or more) mirrored drives in a vdev, but assume it may have 2 or more “striped” vdevs in the pool)
Answer YES (for each) if removing the device would result in downgraded state until either a) the device is restored/replaced or b) the pool+vdev is destroyed and start all over.
Answer NO (for each) if removing the device would NOT result in a downgraded state, meaning that it is safe to remove the device (without replacement) and the pool/vdev will be fine as-is.
I did search through the TrueNAS docs and the forum, but didn’t find an obvious answer for 2 of the devices. I believe the answer for the SLOG is NO (based on one other posting a few years ago), but just wanted to check on all 3 devices in one posting to have concise answers for each.
Thanks.
1) SLOG
2) L2ARC
3) A mirrored drive (assuming no RAIDZ at all, just multiple (3 or more) mirrored drives in a vdev, but assume it may have 2 or more “striped” vdevs in the pool)
Answer YES (for each) if removing the device would result in downgraded state until either a) the device is restored/replaced or b) the pool+vdev is destroyed and start all over.
Answer NO (for each) if removing the device would NOT result in a downgraded state, meaning that it is safe to remove the device (without replacement) and the pool/vdev will be fine as-is.
I did search through the TrueNAS docs and the forum, but didn’t find an obvious answer for 2 of the devices. I believe the answer for the SLOG is NO (based on one other posting a few years ago), but just wanted to check on all 3 devices in one posting to have concise answers for each.
Thanks.
