Re: ZFS dataset stats

On Fri, Jul 15, 2022 at 8:05 AM Zane C. B-H <v.velox@vvelox.net> wrote:

> So was just looking and for some reason nread etc for the ZFS storage
> stats.
>
> Below is a example of a ZFS dataset being used by CBSD to store a raw
> disk image,
> one that is running currently, but for some reasonn the R/W stats don't
> seem actually update.
>
> kstat.zfs.storage.dataset.objset-0x1d41.nread: 0
> kstat.zfs.storage.dataset.objset-0x1d41.reads: 0
> kstat.zfs.storage.dataset.objset-0x1d41.nwritten: 0
> kstat.zfs.storage.dataset.objset-0x1d41.writes: 0
> kstat.zfs.storage.dataset.objset-0x1d41.dataset_name:
> storage/debian10_test/dsk1.vhd
>
> Is there any way to get ZFS to actually keep these up to date for use
> cases
> like this?
>
>
Try to switch default ZFS volmode properties in CBSD from 'dev' to 'full' (
defaults: https://github.com/cbsd/cbsd/blob/develop/etc/defaults/zfs.conf
), e.g:

cat > ~cbsd/etc/zfs.conf <<EOF
default_ci_zvol_volmode="geom"
default_vm_zvol_volmode="geom"
volmode="geom"
EOF

in this case, new VMs will be created in a 'geom' mode:

# cbsd bcreate jname=vm1 vm_os_type=linux vm_os_profile=CentOS-7-x86_64
vm_ram=1g vm_cpus=1 runasap=1 imgsize=10g

# zfs get volmode | grep dsk
jails/mybbuilder130/dsk1.vhd
 volmode   default  default
jails/pxe1/dsk1.vhd
volmode   dev      local
jails/ubvdi1/dsk1.vhd
volmode   default  default
jails/vm1/dsk1.vhd
 volmode   full     local
jails/windows1/dsk1.vhd
volmode   default  default

if you are using cloud/gold images, you may have to delete and get them
again