zfs mirror and unequal writes

[Mike Tancsa]

On 12/8/2017 5:40 PM, Adam Vande More wrote:
> 
> Do you have the disks allocated in any other way eg swap or have a
> member drop out for awhile?
> 
> I checked my mirror which has been in place for ~4 years and the values
> are pretty close, although I have different drives which are mechanical.

Actually, thats the odd thing, swap is on ada0 (only) and its the one
with dramatically less writes.  I looked a few recently deployed SSD
boxes and they are all very close as well.  This is the one outlier. Not
sure if its indicative of some other pathology of the drive ?

0{backup4}# grep swap /etc/fstab
/dev/ada0p2             none    swap    sw              0       0
#/dev/ada1p2            none    swap    sw              0       0
0{backup4}# ls -l /etc/fstab
-rw-r--r--  1 root  wheel  uarch 111 Oct 24  2014 /etc/fstab
0{backup4}#


1{backup4}# gpart show ada0
=>       34  250069613  ada0  GPT  (119G)
         34          6        - free -  (3.0K)
         40       1024     1  freebsd-boot  (512K)
       1064   41943040     2  freebsd-swap  (20G)
   41944104  208125536     3  freebsd-zfs  (99G)
  250069640          7        - free -  (3.5K)

0{backup4}# gpart show ada1
=>       34  250069613  ada1  GPT  (119G)
         34          6        - free -  (3.0K)
         40       1024     1  freebsd-boot  (512K)
       1064   41943040     2  freebsd-zfs  (20G)
   41944104  208125536     3  freebsd-zfs  (99G)
  250069640          7        - free -  (3.5K)

0{backup4}#


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Mike Tancsa, tel +1 519 651 3400
Sentex Communications, mike at sentex.net
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