top -m io missing read/write performance counters in 12.0

eddiert

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Joined
Feb 11, 2021
Messages
4
Running top -m io (or pressing m interactively) shows metrics initially but after the first refresh shows zero in the read/write columns. VCSW/IVCSW columns continue to show data. Fault occasionally shows data.
1613083293057.png

running top -m io -d 1 shows data and then exits normally
1613083339825.png
zpool
Have tried under multiple desktop class systems. 12.0 U1.1, 12.0 U2, new install and upgrades.
Under Freenas 11.3 top -m io shows proper performance metrics.
zpool iostat 1 shows plenty of traffic at the zfs level.
1613083377435.png


Can someone running 12.0 confirm and possibly point out some workarounds so I can troubleshoot per process IO?
 

eddiert

Cadet
Joined
Feb 11, 2021
Messages
4
Confirmed behavior in 12.0 release, also under hyper-v virtual machine.
Can anyone confirm or deny?
 

eddiert

Cadet
Joined
Feb 11, 2021
Messages
4
Also tested plain Freebsd 12.2 and it worked fine so points to a Truenas specific issue.
 
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