Newbie here – I have a NAS running Truenas Scale EE.
Originally set up with 2 x 10tb HDD (Ironwolf) in mirror.
Storage s at 70% so I am trying to add a third drive (12tb Ironwolf – was a better deal than 10tb – yes I know the extra size is of little benefit)
I followed a video tutorial but it did not go as planned.
The drive is there but showing a Data VDEV “mixed capacity” error
I’m just a bit cautious as to what to do – don’t want to stuff it up.
Please – simple language support as I am still learning.
Thank you.
personally you need a fourth drive… 2 x 12tb mirror then add it to pool
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you can’t expand a mirror by one drive. It would only turn the 2-way mirror into a 3-way mirror. As already mentioned, to gain more space in a mirror, you have to add another mirrored vdev which turns your pool into a stripe of 2 mirrors.
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Thank you - I will order a second 12tb drive - should I uninstall the drive I just installed or wait till the second arrives? If I should remove it - how do I do that? Thank you.
what exactly did you do?
Did you already add the drive?
Pls connect to you box and use
sudo zpool status -v
and post the output in code tags.
pool: DataStore
state: ONLINE
status: One or more devices is currently being resilvered. The pool will
continue to function, possibly in a degraded state.
action: Wait for the resilver to complete.
scan: resilver in progress since Wed Feb 26 07:18:08 2025
1.06T / 6.60T scanned at 542M/s, 384G / 6.60T issued at 192M/s
384G resilvered, 5.68% done, 09:27:35 to go
config:
NAME STATE READ WRITE CKSUM
DataStore ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
00c8077d-c58f-48e7-b64b-66cd459380af ONLINE 0 0 0
bb43d45f-491e-4caa-8d6e-15e2c7d9a6c5 ONLINE 0 0 0
8515adb9-946e-426b-87c5-ac36fc289c60 ONLINE 0 0 0 (resilvering)
errors: No known data errors
pool: boot-pool
state: ONLINE
scan: scrub repaired 0B in 00:00:11 with 0 errors on Sun Feb 23 03:45:12 2025
config:
NAME STATE READ WRITE CKSUM
boot-pool ONLINE 0 0 0
sdb3 ONLINE 0 0 0
errors: No known data errors
truenas_admin@DownieServer[~]$
looks like it turning a 2-way mirror into a 3-way mirror
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So I get no extra HDD space? Just extra redundancy? I don’t know how to fix this - will have to do a lot more reading. Thanks
After the resilvering is done you should be able to remove the third drive and turn your 3-way mirror back into a 2-way, buy another drive and then add the second mirror vdev. Then you get the extra space.
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Thank you - when I remove the third drive will it resilver again or just work as 2 x mirror?
I believe it will resilver again, but i’ve never tried it myself since i’m using raidz and not mirrors.
Thank you
I originally set it us as mirror as I didn’t think I would need more space but ripping our movie collection has filled it up quicker than I calculated. I might have to look at setting up RaidZ - I think that is beyond me at the moment, I think it would mean setting up a new pool with new drives and possibly copy everything across. Thanks again for your help.
Correct - might be worth it if budget allows for 3 12tb drives, though arguably raidz2 with 4 12tb drives may be more risk appropriate due to drive size.
I’m still trying to get my head around Raid / mirror etc.
My drive is only for the storage of my own DVD collection - while backup is ideal, I still have the physical discs to rip again. Storage capacity is more important. With mirror, I get 50% of the space I pay for - 4 x 10tb drives in mirror gives me 20tb of useable space but my understanding is in Raidz1 4 x 10tb drives gives me 30tb of useable space. I think it will be a nightmare to re-configure. Thanks
So it has finished resilvering and as suggested I now have a 3 drive mirror pool. Can someone advise how to go back to a 2 drive mirror so I can start again - add 2 more drives (instead of one) in a new mirror. Thank you.
Detach. There should not be any resilver as you are just dropping a mirror. The data is the same on all three drives. It is not degraded.
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Thank you - will it then resilver or will it operate in a degraded state?