Building a new True NAS sys, starting with 4 drives, but want to build out to 8

TrueNAS General
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…and presumably would start with a Z1 config. How difficult would it be to add 4 additional drives to the storage pool, at a Z2 configuration?

Thanks!
-Rodney

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I think you need to explain what you mean.

Starting with a Raid-Z1 VDEV(1) of four drives and then adding a Raid-Z2 VDEV(2) of four drives to a single pool? Do you mean some other layout?

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You may now expand the width of a raidz vdev, but you can not change the level.
If the endgame is a 8-wide raidz2 you should start from a (4-wide) raidz2.

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Thanks for the response. I want to end up with Z2, and 8 drives.

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Thanks for the response. So, yes the end game is 8 drives, raidz2. Based on your info, I should start with 4 drives, raidz2, then add drives as I can afford to add them, with the goal being 8 drives total? The issue is I cannot afford to add all 8 drives at once – don’t have the initial budget. But if I can over time as money becomes available, that would be great.

And the final 8 drive raidz2 config, building out from 4, will be just as if I started with 8 to begin with?

Thanks!
-Rodney

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Starting with 4 drives Raid-Z2 is okay. You can add additional drives using Raid-Z expansion but the space reporting in the GUI will be off. The CLI should be closer to the truth. The more drives you start with, the better.

Plenty of posts with RAID-Zx-expansion tag, if you want to view others thoughts

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No.

There are some caveats.

  1. data already stored will have the same storage efficiency as when originally stored, until rewritten

  2. RaidZ Expansion space accounting is incorrect.

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For the love of the world, while we still have your attention and before you purchase anything: Please make sure that the drives you plan to purchase are not SMR. Especially if you plan to manage a pool of an 8-wide vdev.

You can post the model numbers in here if you are unsure.

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Thanks for the help…

HGST Ultrastar DC HC570 0F48052 22 TB Hard Drive - 3.5 Internal - SAS [12Gb/s SAS]

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-Rodney

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I think you are fine with that drive but only buy from know, good suppliers. Check the drives as soon as you get them to see if they are ‘used and abused’. Good suppliers will take care of problems and returns.

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The Amazon specs don’t specify SMR, but further digging reveals the drive is CMR, Conventional Magnetic Recording. Thoughts if this is a capable TrueNAS drive for running an 8-wide vdev, raidz2?

Thanks!

-Rodney

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Thanks! Good to know.

-Rodney

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No problems running those 8 wide. Only issue is buying through a good supplier. I don’t know if Amazon counts. The inventory may get mixed between online stores.

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Thanks!

Wondering if there is benefit to creating two vdevs, 4-wide, at raidz1, VS 1 vdev, 8-wide, at raidz2.

Thanks again!

-Rodney

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I would do a single vdev, RaidZ2.

If you were looking at say 15/16 drives then I would have said 2 vDev’s of RaidZ2 each.

doing more Vdev’s with only 8 drives will cost you allot of “useable/backup blocks” copies.

G

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More IOPS but any drive failure would put the whole pool at risk, and resilver is going to be long… :fearful:

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Good know. Think I’ll start with 8 drives.

Thanks for the insight!

-Rodney

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Point taken. Thanks!

Is it possible for the TrueNAS OS to be installed on an NVMe drive and boot from it, so long as the drive is mapped into the system VIA a spare PCIe slot?

Thanks!

-Rodney

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Of course you can boot from a small NVMe drive; that’s the preferred way to boot without dedicating a precious SATA port.

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Nice! Thanks!

-Rodney