SOLVED Should a Log device be in use during a ZFS Receive?

[Han Sooloo]

Doing replication from A to B (both FreeNAS 11.2). B has 12x8TB HDDs in RAIDZ-2 configuration, and an Intel Optane 375GB NVMe drive for log.

When I look at the statistics on B, I don't ever see the log being used. Is this expected?

Code:

                                           capacity     operations    bandwidth
pool                                    alloc   free   read  write   read  write
--------------------------------------  -----  -----  -----  -----  -----  -----
tank                                    3.89T  83.1T      0  1.55K      0   199M
  raidz2                                3.89T  83.1T      0  1.55K      0   199M
    gptid/cbbbedab-4024-11e9-a420-70ea1a599c16      -      -      0    131      0  22.5M
    gptid/cee35795-4024-11e9-a420-70ea1a599c16      -      -      0    136      0  22.5M
    gptid/d20d18fd-4024-11e9-a420-70ea1a599c16      -      -      0    131      0  22.6M
    gptid/d52b6f60-4024-11e9-a420-70ea1a599c16      -      -      0    124      0  21.9M
    gptid/d86ebc05-4024-11e9-a420-70ea1a599c16      -      -      0    132      0  22.6M
    gptid/db985bfb-4024-11e9-a420-70ea1a599c16      -      -      0    118      0  21.8M
    gptid/debaf1ea-4024-11e9-a420-70ea1a599c16      -      -      0    131      0  21.7M
    gptid/e1e90f89-4024-11e9-a420-70ea1a599c16      -      -      0    126      0  21.7M
    gptid/e5321a86-4024-11e9-a420-70ea1a599c16      -      -      0    140      0  22.5M
    gptid/e86381b3-4024-11e9-a420-70ea1a599c16      -      -      0    117      0  21.8M
    gptid/eba8d62e-4024-11e9-a420-70ea1a599c16      -      -      0    129      0  22.6M
    gptid/eedd141b-4024-11e9-a420-70ea1a599c16      -      -      0    118      0  21.8M
logs                                        -      -      -      -      -      -
  gptid/efd01a1e-4024-11e9-a420-70ea1a599c16   132K   348G      0      0      0      0
--------------------------------------  -----  -----  -----  -----  -----  -----

 

[HoneyBadger]

Nope, ZFS recv is asynchronous because it's assumed to be pulling from a consistent snapshot, and has the ability to resume an interrupted replication.

If that's all that system B is doing, go ahead and rescue that Optane card from a life of boredom.