I am new to both TrueNAS as well as NAS’s in general, so please be gentle. I very recently built my first NAS and have had it up and running with TrueNAS Scale for less than a week now. Last night I heard the NAS going nuts in terms of HDD activity but didn’t think too much of it an went to sleep. As of this morning I receive an error saying that windows cannot access the NAS shared folders in file explorer. So I logged into the TrueNAS UI and it shows that my storage is not 100%, and I see a low capacity warning.
Is there any easy way to recover from this? Or do I have to delete my storage pool and create a new one. I still have the files that were on the NAS saved elsewhere so that wouldn’t be the end of the world, but I would prefer to not have to do all that work again. That and I wouldn’t feel too confident going forward in TrueNAS keeping my data safe accessible.
Thanks for any and all help.
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I’d recommend disabling any SMB services, or anything else that might access the pool in question (apps, vms, whatever) temporarily. Creating some free space by manually deleting files using CLI, and then go from there.
It is also really strange that you randomly have a pool that is 100% full - you should really investigate why that happened.
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So I went back in to disable SMB services as you advised and I found that it was already turned off, despite being set to start automatically.
When I tried to turn it back on I received the following error:
# CallError
[EFAULT] [Errno 28] No space left on device: ‘/var/db/system/samba4’
As for the storage page, when I go there I see that other than available capacity being 0 B everything seems to be happy, as far as I can tell at least. All of my drives show up in the topology box, and in the ZFS health box the Pool Status shows as Online and total ZFS error are 0.
And to you last point about investigating how this happened I really don’t know where to begin. According to the Alerts that I see at the top right of the UI the disks filled up in the middle of the night last night when everyone in my home was asleep and every computer that has access to the NAS was turned off. As far as I can tell the NAS did this to itself.
I’ll start digging into how to delete files from CLI, hopefully that’s the ticket.
SMB services won’t start of course when you’re 100% full. It requires being able to write some state to the pool. You should track down why it filled like this. If I were to hazard a guess it’s probably related to snapshots. What is the output of zfs list -o space?
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Here’s what I get when I type that in:
[truenas]> zfs list -o space
Namespace zfs not found
I don’t know if need to enter a directory before inputting that command, I really am green as a NAS user. And my Linux command line is really rusty, it’s been at least 10 years since the last time.
I just wanted to quickly add that in the Data Protection box in the Datasets section of the GUI it shows Total Snapshots: 0, so I don’t think that snapshots are the cause here.
try sudo zfs list -o space
Paste the results back here using Preformatted text </> on tool bar or Ctrl+e
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I get that “Namespace sudo not found”. I am typing this in to the root, immediately after typing in ‘cli’ at the initial prompt. Should I be in a specific directory before entering this?
Open the Linux shell, not TrueNAS CLI. I just tested in on Fangtooth 25.04.1
I didn’t need ‘sudo’ before it.
If you need to get out of TrueNAS CLI, type ‘exit’ and hit enter. Wait a bit and you should be back to the usual console screen
Are you using the console of the computer, aka keyboard, mouse and monitor or are your in the GUI and in the Shell? System menu then Shell?
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That worked! Thanks for the advice SmallBarky. Here is the result when I enter the command into the right place:
NAME AVAIL USED USEDSNAP USEDDS USEDREFRESERV USEDCHILD
CameroNAS 0B 49.3T 0B 140K 0B 49.3T
CameroNAS/.system 0B 133M 0B 174K 0B 133M
CameroNAS/.system/configs-ae32c386e13840b2bf9c0083275e7941 0B 1.09M 0B 1.09M 0B 0B
CameroNAS/.system/cores 0B 140K 0B 140K 0B 0B
CameroNAS/.system/netdata-ae32c386e13840b2bf9c0083275e7941 0B 131M 0B 131M 0B 0B
CameroNAS/.system/nfs 0B 163K 0B 163K 0B 0B
CameroNAS/.system/samba4 0B 291K 0B 291K 0B 0B
CameroNAS/NAS_Main 0B 49.2T 0B 49.2T 0B 169K
CameroNAS/NAS_Main/slaptop 0B 169K 0B 169K 0B 0B
boot-pool 212G 2.84G 0B 96K 0B 2.84G
boot-pool/ROOT 212G 2.81G 0B 96K 0B 2.81G
boot-pool/ROOT/25.04.1 212G 2.81G 0B 174M 0B 2.64G
boot-pool/ROOT/25.04.1/audit 212G 1.40M 0B 1.40M 0B 0B
boot-pool/ROOT/25.04.1/conf 212G 7.05M 0B 7.05M 0B 0B
boot-pool/ROOT/25.04.1/data 212G 268K 0B 268K 0B 0B
boot-pool/ROOT/25.04.1/etc 212G 7.15M 1012K 6.16M 0B 0B
boot-pool/ROOT/25.04.1/home 212G 116K 0B 116K 0B 0B
boot-pool/ROOT/25.04.1/mnt 212G 96K 0B 96K 0B 0B
boot-pool/ROOT/25.04.1/opt 212G 96K 0B 96K 0B 0B
boot-pool/ROOT/25.04.1/root 212G 144K 0B 144K 0B 0B
boot-pool/ROOT/25.04.1/usr 212G 2.53G 0B 2.53G 0B 0B
boot-pool/ROOT/25.04.1/var 212G 95.8M 808K 5.07M 0B 89.9M
boot-pool/ROOT/25.04.1/var/ca-certificates 212G 96K 0B 96K 0B 0B
boot-pool/ROOT/25.04.1/var/lib 212G 27.1M 200K 26.8M 0B 96K
boot-pool/ROOT/25.04.1/var/lib/incus 212G 96K 0B 96K 0B 0B
boot-pool/ROOT/25.04.1/var/log 212G 62.8M 0B 12.2M 0B 50.6M
boot-pool/ROOT/25.04.1/var/log/journal 212G 50.6M 0B 50.6M 0B 0B
boot-pool/grub 212G 8.42M 0B 8.42M 0B 0B
That is showing everything is in NAS_Main with 49.2TB in that pool.
You should be able to browse and check to see what is taking up the space in there.
The command ‘du’ will help you see the size of folders, subfolders, etc. Run ‘man du’ to get a description of options for using it. You may have to use ‘sudo’ before the command, depending on what console or Shell you are in.
du -h /mnt/NAS_Main should get you started. You can also look to see what files and folders are in there.
I’d suggest actually starting with du -h -d1 /mnt/NAS_Main
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So thanks to the help from everyone above and a little of my own searching I was able to delete enough files to be able to turn the SMB service back on, which allowed my to get in with windows file explorer. I have new questions now that I have though.
If I add all of the space that the various folders are reporting as taking up, it only adds up to ~26 TB of space used. Despite that, my storage on the GUI is showing as ~48 TB used and just over 1 TB available.
How can I find where/how this missing space is being taken up?
We need to know more details on your system. Is this just used for storage or do you have apps and/or VMs running on TrueNAS? If you do, what apps and/or VMs?
Browse some other threads and do the Tutorial by the Bot to get your forum trust level up so you can post images, etc.
TrueNAS-Bot
Type this in a new reply and send to bring up the tutorial, if you haven’t done it already.
@TrueNAS-Bot start tutorial
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No apps or VMs currently. I have a few that I would like to get into but so far all I’ve done is get the system set up to be a file server and nothing else. I’ll do the tutorial in the meantime.
I’ve completed the tutorial and now am able to post images. I’ve added a screenshot of what I see in the Storage page of the TrueNAS GUI, which still shows the availlable storage as being almost full. When I look at the folder in the NAS in windows file explorer their sum total comes to 14 TB.
How can I figure out where the extra space has gone?
What have you done on cleaning up files?
run sudo zfs list -o space and paste the results back using preformatted text as you did before.
You can try the following also. This should show the pool and drive info
sudo ZPOOL_SCRIPTS_AS_ROOT=1 zpool status -vLtsc lsblk,serial,smartx,smart
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The Windows data is a share, which shows you using almost all 14 TB of the share. If it’s really the whole pool as the zfs list shows, then, the Windows numbers are for sure wrong as you don’t have 14TB storage. Maybe you set a quota? Not sure how Windows would show that. I don’t use quotas so maybe one is set?
How big are the drives in the Raidz1?
Well, curious for me is the topology section shows 10.91TiB. Mine shows the same in topology and usage as far as total capacity.
Still want to see the results of:
du -h -d1 /mnt/NAS_Main
And did you ever add another drive to your existing raidz1 pool?
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I use command line in the console of the computer to delete a few files in the Movies folder, enough to re-enable the SMB service, which let me use File Explorer to access the remaining files from my Windows PC again.
Here is the result from the first command you requested:
NAME AVAIL USED USEDSNAP USEDDS USEDREFRESERV USEDCHILD
CameroNAS 1.07T 48.1T 0B 140K 0B 48.1T
CameroNAS/.system 1.07T 133M 0B 465K 0B 133M
CameroNAS/.system/configs-ae32c386e13840b2bf9c0083275e7941 1.07T 1.09M 0B 1.09M 0B 0B
CameroNAS/.system/cores 1024M 140K 0B 140K 0B 0B
CameroNAS/.system/netdata-ae32c386e13840b2bf9c0083275e7941 1.07T 131M 0B 131M 0B 0B
CameroNAS/.system/nfs 1.07T 163K 0B 163K 0B 0B
CameroNAS/.system/samba4 1.07T 291K 0B 291K 0B 0B
CameroNAS/NAS_Main 1.07T 48.0T 0B 48.0T 0B 169K
CameroNAS/NAS_Main/slaptop 1.07T 169K 0B 169K 0B 0B
boot-pool 212G 2.90G 0B 96K 0B 2.90G
boot-pool/ROOT 212G 2.86G 0B 96K 0B 2.86G
boot-pool/ROOT/25.04.1 212G 2.86G 0B 174M 0B 2.69G
boot-pool/ROOT/25.04.1/audit 212G 2.01M 0B 2.01M 0B 0B
boot-pool/ROOT/25.04.1/conf 212G 7.05M 0B 7.05M 0B 0B
boot-pool/ROOT/25.04.1/data 212G 268K 0B 268K 0B 0B
boot-pool/ROOT/25.04.1/etc 212G 7.15M 1012K 6.16M 0B 0B
boot-pool/ROOT/25.04.1/home 212G 120K 0B 120K 0B 0B
boot-pool/ROOT/25.04.1/mnt 212G 96K 0B 96K 0B 0B
boot-pool/ROOT/25.04.1/opt 212G 96K 0B 96K 0B 0B
boot-pool/ROOT/25.04.1/root 212G 144K 0B 144K 0B 0B
boot-pool/ROOT/25.04.1/usr 212G 2.53G 0B 2.53G 0B 0B
boot-pool/ROOT/25.04.1/var 212G 148M 808K 5.07M 0B 142M
boot-pool/ROOT/25.04.1/var/ca-certificates 212G 96K 0B 96K 0B 0B
boot-pool/ROOT/25.04.1/var/lib 212G 27.1M 200K 26.8M 0B 96K
boot-pool/ROOT/25.04.1/var/lib/incus 212G 96K 0B 96K 0B 0B
boot-pool/ROOT/25.04.1/var/log 212G 115M 0B 65.2M 0B 49.7M
boot-pool/ROOT/25.04.1/var/log/journal 212G 49.7M 0B 49.7M 0B 0B
boot-pool/grub 212G 8.42M 0B 8.42M 0B 0B
truenas_admin@truenas[~]$
And here is the result from the second command:
pool: CameroNAS
state: ONLINE
config:
NAME STATE READ WRITE CKSUM SLOW size vendor model serial pwr_cyc hours_on health temp nvme_err realloc pend_sec off_ucor ata_err rep_ucor cmd_to
CameroNAS ONLINE 0 0 0 -
raidz1-0 ONLINE 0 0 0 -
sda1 ONLINE 0 0 0 0 10.9T ATA WDC WD120EFBX-68B0EN0 D7JUBUPN 3 317 PASSED 36 - 0 0 0 - - - (trim unsupported)
sde1 ONLINE 0 0 0 0 10.9T ATA WDC WD120EFBX-68B0EN0 5QKBHN3B 2274 19754 PASSED 39 - 0 0 0 - - - (trim unsupported)
sdd1 ONLINE 0 0 0 0 10.9T ATA WDC WD120EFBX-68B0EN0 5QJ6K16B 2303 21499 PASSED 37 - 0 0 0 - - - (trim unsupported)
sdb1 ONLINE 0 0 0 0 10.9T ATA WDC WD120EFBX-68B0EN0 D7JVW4HN 3 317 PASSED 32 - 0 0 0 - - - (trim unsupported)
cache
nvme0n1p1 ONLINE 0 0 0 0 931.5G - WD Blue SN5000 1TB 252114804244 6 317 PASSED 35 0 - - - - - - (untrimmed)
errors: No known data errors
pool: boot-pool
state: ONLINE
scan: scrub repaired 0B in 00:00:06 with 0 errors on Sat Jul 19 03:45:08 2025
config:
NAME STATE READ WRITE CKSUM SLOW size vendor model serial pwr_cyc hours_on health temp nvme_err realloc pend_sec off_ucor ata_err rep_ucor cmd_to
boot-pool ONLINE 0 0 0 -
sdc3 ONLINE 0 0 0 0 223.6G ATA KINGSTON SA400S37240G 50026B72830CF619 6 317 PASSED 26 - - - - - 0 - (untrimmed)
errors: No known data errors
@sfatula I haven’t set any quotas, so as far as I am aware Windows should see the whole pool. It did initally at least, I was able to see the correct amount of available space when I first set everything up.
The drives in the Raidz1 are 4 x 12 TB.
And here are the results of the command you requested:
du: cannot read directory '/mnt/CameroNAS/NAS_Main/basement': Permission denied
512 /mnt/CameroNAS/NAS_Main/basement
du: cannot read directory '/mnt/CameroNAS/NAS_Main/slaptop': Permission denied
512 /mnt/CameroNAS/NAS_Main/slaptop
2.5T /mnt/CameroNAS/NAS_Main/Movies
4.5T /mnt/CameroNAS/NAS_Main/TV
4.5T /mnt/CameroNAS/NAS_Main/Incognito
du: cannot read directory '/mnt/CameroNAS/NAS_Main/playroom': Permission denied
12K /mnt/CameroNAS/NAS_Main/playroom
1.9T /mnt/CameroNAS/NAS_Main/Kids Stuff
217G /mnt/CameroNAS/NAS_Main/Documentaries
802G /mnt/CameroNAS/NAS_Main/Pictures
du: cannot read directory '/mnt/CameroNAS/NAS_Main/mainuser': Permission denied
12K /mnt/CameroNAS/NAS_Main/mainuser
15T /mnt/CameroNAS/NAS_Main
