Used/available storage problems

[elagil]

Hello!

I have issues of understanding, why I have a certain amount of allocated storage on my volume. I have a volume over two 3 TB disks in a mirror configuration.

My volume is called "v1" and contains a few datasets. I do not store data in the root of the volume directly. See "vol.PNG" for a picture of the configuration. I actually use 500 GB of that volume with data within the datasets. I have basically no snapshots at the moment. However, I fail to see, why significantly more than 500 GB are occupied on v1.

When I look for occupied space on my drive, I get this (extracted only data about v1):

Code:

root@freenas:/mnt/v1 # zfs get all | grep used
v1															 used						  984G										   -
v1															 usedbysnapshots			   104K										   -
v1															 usedbydataset				 472G										   -
v1															 usedbychildren				512G										   -
v1															 usedbyrefreservation		  0											  -
v1															 logicalused				   1011G										  -
v1@auto-20171126.1042-3m									   used						  104K										   -
v1@auto-20171126.1042-3m									   logicalused				   0											  -
v1/Bilder													  used						  459G										   -
v1/Bilder													  usedbysnapshots			   24.7M										  -
v1/Bilder													  usedbydataset				 459G										   -
v1/Bilder													  usedbychildren				0											  -
v1/Bilder													  usedbyrefreservation		  0											  -
v1/Bilder													  logicalused				   465G										   -
v1/Bilder@auto-20171126.1042-3m								used						  24.7M										  -
v1/Bilder@auto-20171126.1042-3m								logicalused				   0											  -
v1/Daten													   used						  160K										   -
v1/Daten													   usedbysnapshots			   56K											-
v1/Daten													   usedbydataset				 104K										   -
v1/Daten													   usedbychildren				0											  -
v1/Daten													   usedbyrefreservation		  0											  -
v1/Daten													   logicalused				   65K											-
v1/Daten@auto-20171126.1042-3m								 used						  56K											-
v1/Daten@auto-20171126.1042-3m								 logicalused				   0											  -
v1/Daten2													  used						  15.3G										  -
v1/Daten2													  usedbysnapshots			   34.1M										  -
v1/Daten2													  usedbydataset				 15.2G										  -
v1/Daten2													  usedbychildren				0											  -
v1/Daten2													  usedbyrefreservation		  0											  -
v1/Daten2													  logicalused				   26.8G										  -
v1/Daten2@auto-20171126.1042-3m								used						  34.1M										  -
v1/Daten2@auto-20171126.1042-3m								logicalused				   0											  -
v1/Musik													   used						  34.9G										  -
v1/Musik													   usedbysnapshots			   1.22M										  -
v1/Musik													   usedbydataset				 34.9G										  -
v1/Musik													   usedbychildren				0											  -
v1/Musik													   usedbyrefreservation		  0											  -
v1/Musik													   logicalused				   35.3G										  -
v1/Musik@auto-20171126.1042-3m								 used						  1.22M										  -
v1/Musik@auto-20171126.1042-3m								 logicalused				   0											  -
v1/backup-gmbh												 used						  2.79G										  -
v1/backup-gmbh												 usedbysnapshots			   12.1M										  -
v1/backup-gmbh												 usedbydataset				 2.78G										  -
v1/backup-gmbh												 usedbychildren				0											  -
v1/backup-gmbh												 usedbyrefreservation		  0											  -
v1/backup-gmbh												 logicalused				   6.32G										  -
v1/backup-gmbh@auto-20171126.1042-3m						   used						  12.1M										  -
v1/backup-gmbh@auto-20171126.1042-3m						   logicalused				   0	  

Do you have an idea, where this space is occupied? I am concerned about the "usedbydataset" property of v1, as there should be no data unique to this dataset. The data is all contained in the datasets within v1.

This is the output uf "zpool list": There is another volume v0 which is just a single disk.

Code:

root@freenas:/mnt/v1 # zpool list
NAME		   SIZE  ALLOC   FREE  EXPANDSZ   FRAG	CAP  DEDUP  HEALTH  ALTROOT
freenas-boot  29.8G  4.29G  25.5G		 -	  -	14%  1.00x  ONLINE  -
v0			 220G  15.6G   204G		 -	29%	 7%  1.00x  ONLINE  /mnt
v1			2.72T   984G  1.76T		 -	20%	35%  1.00x  ONLINE  /mnt

Thank you for any advice,
Adrian

 

[danb35]

I do not store data in the root of the volume directly.

The output of zfs get all that you posted tells a different story. What's the output of du -sh /mnt/v1 and du -sh /mnt/v1/*?

 

[elagil]

So, these are the outputs that you asked for

Code:

root@freenas:~ # du -sh /mnt/v1
512G	/mnt/v1

root@freenas:~ # du -sh /mnt/v1/*
2.9G	/mnt/v1/backup-gmbh
459G	/mnt/v1/Bilder
 19K	/mnt/v1/Daten
 15G	/mnt/v1/Daten2
 35G	/mnt/v1/Musik

Am I missing something or is "du" not showing the 472 GB that should be unique to /mnt/v1? I also do not see any hidden files or does the ZFS file system hide them in a special way?

Best regards!

 

[elagil]

It seems like the problem is solved.

I unmounted all datasets but still found non-empty folders within v1 with some older versions of files of the usually mounted datasets. Of course, the names of the datasets and these folders were equal, so that the folders contained in v1 were invisible once the datasets were mounted.

After deleting the folders and mounting all datasets, the discrepancy is gone. v1 shows the correct size of free space.

I still wonder why this happened. I never unmounted the datasets before.

Code:

root@freenas:~ # zpool list
NAME		   SIZE  ALLOC   FREE  EXPANDSZ   FRAG	CAP  DEDUP  HEALTH  ALTROOT
freenas-boot  29.8G  4.29G  25.5G		 -	  -	14%  1.00x  ONLINE  -
v0			 220G  15.4G   205G		 -	29%	 7%  1.00x  ONLINE  /mnt
v1			2.72T   513G  2.22T		 -	 9%	18%  1.00x  ONLINE  /mnt