Storage question

Paul Kraus paul at
Thu Sep 10 00:51:56 UTC 2015

On Sep 9, 2015, at 16:38, William A. Mahaffey III <wam at> wrote:

> Actually, I do have 1 more question. Partway down in the setup, stuff is echoed to /tmp/bsdinstall_etc/fstab to setup swap, but nothing about the other parts of the FS (ZFS stuff) .... Is that AOK ? TIA & have a good one.

ZFS handles mounts itself. One of the properties of a mountable dataset is “mountpoint”. take a look at the ‘zfs mount -a’ command and picture it being run at boot time.

Under 9.x you used to have to still put the / filesystem in /etc/fstab (and set the mountpoint to “legacy” in zfs. Under 10.x the zfs boot loader knows how to find and mount the / filesystem, so you do not need an /etc/fstab at all (except for swap as pervious discussed).

The zfs configuration on my home server is:

[ppk at FreeBSD2 ~]$ zpool status
  pool: KrausHaus
 state: ONLINE
  scan: scrub repaired 0 in 2h30m with 0 errors on Thu Jul 16 00:28:32 2015

	NAME                             STATE     READ WRITE CKSUM
	KrausHaus                        ONLINE       0     0     0
	  mirror-0                       ONLINE       0     0     0
	    diskid/DISK-Z1W1ZKD6         ONLINE       0     0     0
	    diskid/DISK-Z1N3V3J9         ONLINE       0     0     0
	    diskid/DISK-WD-WMC5K0159058  ONLINE       0     0     0
	  mirror-1                       ONLINE       0     0     0
	    diskid/DISK-Z1N08WTM         ONLINE       0     0     0
	    diskid/DISK-JPW9K0N018164L   ONLINE       0     0     0
	    diskid/DISK-Z1N3WQ8V         ONLINE       0     0     0
	  mirror-2                       ONLINE       0     0     0
	    diskid/DISK-WD-WMC5K0157777  ONLINE       0     0     0
	    diskid/DISK-9QJ5252G         ONLINE       0     0     0
	    diskid/DISK-Z1W20AP6         ONLINE       0     0     0

errors: No known data errors

  pool: freebsd2
 state: ONLINE
  scan: scrub repaired 0 in 0h0m with 0 errors on Fri Jun 19 22:28:40 2015

	NAME                                STATE     READ WRITE CKSUM
	freebsd2                            ONLINE       0     0     0
	  mirror-0                          ONLINE       0     0     0
	    diskid/DISK-50026B72350338B2p3  ONLINE       0     0     0
	    diskid/DISK-50026B7235033306p3  ONLINE       0     0     0

errors: No known data errors
[ppk at FreeBSD2 ~]$ zfs list 
NAME                       USED  AVAIL  REFER  MOUNTPOINT
KrausHaus                 1.81T   892G   144K  none
KrausHaus/dnr              144K  1024M   144K  none
KrausHaus/export          1.80T   892G  1.80T  /export
KrausHaus/freebsd1        5.75G   892G  5.75G  /freebsd1
KrausHaus/freebsd2         144K   892G   144K  /freebsd2
KrausHaus/usr-ports       2.42G   892G  2.42G  /usr/ports
KrausHaus/usr-src          997M   892G   997M  /usr/src
freebsd2                  6.02G  9.61G    36K  none
freebsd2/ROOT              679M  9.61G    32K  none
freebsd2/ROOT/10-Release     1K  9.61G   495M  /
freebsd2/ROOT/20140912       1K  9.61G   478M  /
freebsd2/ROOT/default      679M  9.61G   486M  /
freebsd2/dnr                31K  1024M    31K  none
freebsd2/tmp              63.5K  9.61G  63.5K  /tmp
freebsd2/usr              3.92G  9.61G   353M  /usr
freebsd2/usr/local        3.57G  9.61G  3.57G  /usr/local
freebsd2/var               445M  9.61G   423M  /var
freebsd2/var/log          22.1M  9.61G  22.1M  /var/log
[ppk at FreeBSD2 ~]$ 

And the boot drives are partitioned as follows;

[ppk at FreeBSD2 ~]$ gpart show /dev/diskid/DISK-50026B72350338B2
=>       34  234441581  diskid/DISK-50026B72350338B2  GPT  (112G)
         34       1024                             1  freebsd-boot  (512K)
       1058    8388608                             2  freebsd-swap  (4.0G)
    8389666   33554432                             3  freebsd-zfs  (16G)
   41944098   50331648                             4  freebsd-zfs  (24G)
   92275746   50331648                             5  freebsd-zfs  (24G)
  142607394   91834221                                - free -  (44G)

[ppk at FreeBSD2 ~]$ 

They are small (120 GB ) SSDs and my plan was to use part ions 4 and 5 as mirrored SLOG and individual L2ARC devices, but I never got them setup.

This is 10.0 (I need to upgrade to at least 10.1) but I had a very similar configuration for my previous 9.x server.

Note that my entire OS except for /usr/src and /usr/ports lives in 16 GB. I put /usr/src and /usr/ports in the zpool with the data as they receive the vast majority of writes and I wanted to save my SSD write capacity for the SLOG and L2ARC.

Note also the “dnr” datasets :-)

Paul Kraus
paul at

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