I have a server that I am using RaidZ2 and have 8 hard drives and want to expand it to 9 now and maybe up to 12 in the next year. TrueNAS Scale 25.04.2.5 RAM: 64GB 8 x 16TB Hard drives (all CMR, Seagate,) (RaidZ2) 2 x 256GB NVME (boot) MSI Pro Z790-A MAX (i5-12600K) LSI SAS3008 9300-8I IT-Mode HBA…

[image] misterpele: Is that the option I want Yes. [image] misterpele: how do I manually rewrite the data [image] GitHub - markusressel/zfs-inplace-rebalancing: Simple bash script to rebalance pool data between... Simple bash script to rebalance pool data between al…

Note that you main RAID-Z2 is a vDev, (Virtual Device). It is just your only data vDev. [image] misterpele: Or do I use Extend VDEV option in Storage-Datasets? If I do that it says this if I chose that option “The expanded vdev uses the pre-expanded parity ratio, which reduces the total vdev c…

[image] Arwen: Adding just one disk might not make it worth it to re-write all your data, if you plan on adding more disks sooner rather than later. So if I planned to add 2 more 16TB (3 total), I should do it all at once. [image] Arwen: [image] misterpele: Or do I use Extend VDEV op…

[image] misterpele: [image] Arwen: Adding just one disk might not make it worth it to re-write all your data, if you plan on adding more disks sooner rather than later. So if I planned to add 2 more 16TB (3 total), I should do it all at once. You don’t have to do it all at once. But, d…

[image] Arwen: You don’t have to do it all at once. But, doing a re-write to reduce overhead of data to parity ratio, each time you add a disk might not be worth it. Waiting until after you add your last disk might be worth it. You have to choose. So you are saying if I add the drive, I don’t…

[image] misterpele: So you are saying if I add the drive, I don’t have to do the re-write? Correct. With the existing 6 Data to 2 Parity ratio, you get pretty good disk usage. [image] misterpele: If that is the case, what are the downfalls/consequences of not doing that right away? L…

[image] Arwen: With the existing 6 Data to 2 Parity ratio, you get pretty good disk usage. So if I add the 9th drive the “new data” being written, does that only go on the 9th drive until I do the re-write or does it get put with the other 6 Data and 2 Parity I have? And if it gets put in wi…

You are complicating this too much. New data for a 9 disk RAID-Zx vDev gets up to 7 data columns and 2 parity. It depends on if their are 9 column stripes free AND if the write needs that much storage.

[image] Arwen: You are complicating this too much. New data for a 9 disk RAID-Zx vDev gets up to 7 data columns and 2 parity. It depends on if their are 9 column stripes free AND if the write needs that much storage. I probably am. So whatever new stuff gets written will be written on all 7 …

Adding new disk to Pool

TrueNAS General

etorix November 3, 2025, 8:11pm 19

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Adding new disk to Pool

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