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[SOLVED] ZFS Scrub Data Size VS ZFS Pool Used Size

Posted: 16 Sep 2014 09:41
by navi
Question: ZFS Scrub Data Size VS ZFS Pool Used Size

Hi All,

I have a question about the size of data that my ZFS is Scrubbing. You can see in the details below the pool used data size is only 3.61T (49% of total 7.31T usable on RaidZ2 10.9T ). You will also see that ZFS Scrub is reporting that it is scrubbing 5.43T (4.00T scanned out of 5.43T at 289M/s, 1h26m to go, 0 repaired, 73.72% done). My question is what is ZFS Scrubbing as I only have data worth 3.61T?? is there something wrong with my NAS Setup?



Below details are from WebGui (DISK > ZFS > POOLS > COONFIGURATION)

Code: Select all

Pools (1)
====================
Name   = pool1
Size   = 10.9T  	 	 	 	 	 	
Used   = 3.61T (49%) 	 	 	
Free   = 3.52T
Dedup  = 1.00x
Health = ONLINE
Mount point = -
AltRoot = -


Virtual devices (1)
====================
Name = pool1_raidz2_0	 	 	 	 	
Type = raidz2
Pool = pool1
Devices = /dev/ada2, /dev/ada5, /dev/ada1, /dev/ada4, /dev/ada6, /dev/ada3


Datasets (1)
====================
Name = dataset1
Pool = pool1	
Compression = on	
Dedup = off	
Sync = standard
Canmount =	on 
Quota = none
Extended attributes = off
Readonly = off
Snapshot Visibility = hidden


Volumes (0)
====================
Name =
Pool =	
Size =  
Blocksize =  
Sparse = 
Compression =
Dedup =	
Sync = 
Below details are from WebGui (DISK > ZFS > POOLS > INFORMATION) or ZPOOL STATUS in terminal.

Code: Select all

  pool: pool1
 state: ONLINE
  scan: scrub in progress since Mon Sep 15 15:23:34 2014
        4.00T scanned out of 5.43T at 289M/s, 1h26m to go
        0 repaired, 73.72% done
config:

	NAME        STATE     READ WRITE CKSUM
	pool1       ONLINE       0     0     0
	  raidz2-0  ONLINE       0     0     0
	    ada2    ONLINE       0     0     0
	    ada5    ONLINE       0     0     0
	    ada1    ONLINE       0     0     0
	    ada4    ONLINE       0     0     0
	    ada6    ONLINE       0     0     0
	    ada3    ONLINE       0     0     0

errors: No known data errors
My System Config is: 6 x 2T Segat on ZFS RaidZ2 Setup on 2GB RAM and 2.66Ghz Core Duo CPU

Code: Select all

Hostname = nas4free.local
Version = 9.2.0.1 - Shigawire (revision 972)
Build date = Mon Apr 28 02:37:05 CEST 2014
Platform OS = FreeBSD 9.2-RELEASE-p4 (kern.osreldate: 902001)
Platform = x64-full on Intel(R) Core(TM)2 Duo CPU E6750 @ 2.66GHz
System = Gigabyte Technology Co., Ltd. P35-DS4
System bios =Award Software International, Inc. version: F14 06/19/2009
CPU frequency = 2667MHz
Memory = 2017MB
Disk space usage 	
pool1
49% of 10.9TB
Total: 10.9T | Used: 3.61T | Free: 3.52T | State: ONLINE
Thanks,
navi

Re: Question: ZFS Scrub Data Size VS ZFS Pool Used Size

Posted: 16 Sep 2014 19:18
by substr
The larger number is the total data, including parity.

3.61 / .66 = 5.47

.66 = (6 drives - 2 parity drives ) / 6 total drives in your raidz2

Nothing is wrong.

Re: Question: ZFS Scrub Data Size VS ZFS Pool Used Size

Posted: 16 Sep 2014 20:33
by raulfg3
same topic here: viewtopic.php?f=64&t=4757

Re: Question: ZFS Scrub Data Size VS ZFS Pool Used Size

Posted: 17 Sep 2014 18:58
by navi
substr wrote:The larger number is the total data, including parity.

3.61 / .66 = 5.47

.66 = (6 drives - 2 parity drives ) / 6 total drives in your raidz2

Nothing is wrong.
Thanks. I didn't realize ZFS Scrubs the parity data as well. Fantastic.

regards,
navi