I'm finally adding another drive to my home server. # Links - [Disks | TrueNAS Documentation Hub](https://www.truenas.com/docs/scale/scaletutorials/storage/disks/) - VDEV, zpool, ZIL, and L2ARC - [Slideshow explaining VDev, zpool, ZIL and L2ARC for noobs! | TrueNAS Community](https://www.truenas.com/community/threads/slideshow-explaining-vdev-zpool-zil-and-l2arc-for-noobs.7775/) - - Upgrading RAID in TrueNAS Scale - [How to upgrade the raid | TrueNAS Community](https://www.truenas.com/community/threads/how-to-upgrade-the-raid.115473/) - [Built system with 1 drive, now want to add second drive and set to raid 1 | TrueNAS Community](https://www.truenas.com/community/threads/built-system-with-1-drive-now-want-to-add-second-drive-and-set-to-raid-1.6832/) - - [(1) TrueNAS: How To Expand A ZFS Pool - YouTube](https://www.youtube.com/watch?v=11bWnvCwTOU) - [(1) The EASIEST way to Expand Your ZFS Pool in TrueNAS (But is it the Best?) - YouTube](https://www.youtube.com/watch?v=Uzk6Janio0g) - SMR vs CMR - [(5) CMR vs SMR | LinkedIn](https://www.linkedin.com/pulse/cmr-vssmr-ben-moore/) - Going from "Stripe" (no redundancy) to "Mirror" (RAID / redundancy) - [Going from Stripe to Mirror, True NAS Scale | TrueNAS Community](https://www.truenas.com/community/threads/going-from-stripe-to-mirror-true-nas-scale.101765/) - [SOLVED - Change stripe vdev layout to mirror | TrueNAS Community](https://www.truenas.com/community/threads/change-stripe-vdev-layout-to-mirror.112548/) - [Changing a from stripe to mirror in the System Dataset Pool | TrueNAS Community](https://www.truenas.com/community/threads/changing-a-from-stripe-to-mirror-in-the-system-dataset-pool.117444/) - [Change storage configuration from striped to mirrored | TrueNAS Community](https://www.truenas.com/community/threads/change-storage-configuration-from-striped-to-mirrored.111544/) - [Convert 1 drive stripe to 2 drive mirrored : r/truenas](https://www.reddit.com/r/truenas/comments/pn7vhs/convert_1_drive_stripe_to_2_drive_mirrored/) # VDEVs & Disks Explained - VDEVs have drives in them - They are the logical components to a pool - You apply RAID to a VDEV # Adding a Drive to Current Pool, Upgrading to RAID 1 (Two Drives) - Just to be clear, I'm not rich and therefore I had to slowly buy drives. I started with 1 drive - hence RAID 0. Now I have 2 drives which is why I'm moving to a mirrored setup for basic redundancy. -  - Some people seem to think it's simple to upgrade from RAID 0 (1 drive without redundancy) to RAID 1 (mirrored mode) - [Just delete the pool and recrate a new pool with RAID level you want. Export disconnect/delete....](https://www.truenas.com/community/threads/how-to-upgrade-the-raid.115473/) - Can it be easier though? ## Testing "Stripe" to "Mirror" with USB Drives - Going from "Stripe" (no redundancy) to "Mirror" (RAID / redundancy) - [Going from Stripe to Mirror, True NAS Scale | TrueNAS Community](https://www.truenas.com/community/threads/going-from-stripe-to-mirror-true-nas-scale.101765/) - [SOLVED - Change stripe vdev layout to mirror | TrueNAS Community](https://www.truenas.com/community/threads/change-stripe-vdev-layout-to-mirror.112548/) - [Changing a from stripe to mirror in the System Dataset Pool | TrueNAS Community](https://www.truenas.com/community/threads/changing-a-from-stripe-to-mirror-in-the-system-dataset-pool.117444/) - [Change storage configuration from striped to mirrored | TrueNAS Community](https://www.truenas.com/community/threads/change-storage-configuration-from-striped-to-mirrored.111544/) - [Convert 1 drive stripe to 2 drive mirrored : r/truenas](https://www.reddit.com/r/truenas/comments/pn7vhs/convert_1_drive_stripe_to_2_drive_mirrored/) - It looks like the solution to this is called "extending" the pool - Go to "Manage Devices." Notice I have 1 x DISK - 1 wide -  - Drop into the VDEV -  - "Extend" -  - Pick the disk that you want to add on? -  - You may run into "mixed disk capacities" errors - Links - [Mixing drive sizes in a pool | TrueNAS Community](https://www.truenas.com/community/threads/mixing-drive-sizes-in-a-pool.111999/) - [Mixed Disk capacities and strange display of Disks / Status after resilver | TrueNAS Community](https://www.truenas.com/community/threads/mixed-disk-capacities-and-strange-display-of-disks-status-after-resilver.109815/) - [Do all the drives have to be the same size in TrueNAS? : r/freenas](https://www.reddit.com/r/freenas/comments/jor672/do_all_the_drives_have_to_be_the_same_size_in/) - [TrueNAS Scale incorrectly reporting Mixed Capacity VDEVS | TrueNAS Community](https://www.truenas.com/community/threads/truenas-scale-incorrectly-reporting-mixed-capacity-vdevs.114077/) - [Storage Drives of Multiple Sizes? | TrueNAS Community](https://www.truenas.com/community/threads/storage-drives-of-multiple-sizes.85493/) - Some conclusions - [If you mix drives in the same vdev, the capacity of the vdev will be determined by the smallest drive.](https://www.truenas.com/community/threads/storage-drives-of-multiple-sizes.85493/) - ## Extending 12 TB Hard Drive to "Mirror" (RAID 1) - Extending the almost 11 TB VDEV -  -  - It was a success - It takes awhile to fully "resilver" -  # Expanding an Existing Pool - TL;DR - you can't just add one drive to the pool...well actually you kind of can? - ZFS uses Data VDEVs -  - VDEVs don't need same size -  - VDEV does not need to be symmetrical size or drive count -  - Mirrors - You can use this but it's expensive for storage -  - You can have many pools - Datasets are not shared between pools -  - Losing a VDEV loses the -