[SOLVED] zfs "arc_summary" command missing?

[JakeFrosty]

It seems in my Proxmox-VE ZFS/EFI installation the arc_summary command is missing, is this the result of an update?

Here's my package list

proxmox-ve: 9.1.0 (running kernel: 6.17.4-2-pve)
pve-manager: 9.1.6 (running version: 9.1.6/71482d1833ded40a)
proxmox-kernel-helper: 9.0.4
proxmox-kernel-6.17: 6.17.13-2
proxmox-kernel-6.17.13-2-pve-signed: 6.17.13-2
proxmox-kernel-6.17.13-1-pve-signed: 6.17.13-1
proxmox-kernel-6.17.9-1-pve-signed: 6.17.9-1
proxmox-kernel-6.17.4-2-pve-signed: 6.17.4-2
proxmox-kernel-6.14: 6.14.11-6
proxmox-kernel-6.14.11-6-pve-signed: 6.14.11-6
proxmox-kernel-6.14.11-5-pve-signed: 6.14.11-5
proxmox-kernel-6.14.11-4-pve-signed: 6.14.11-4
proxmox-kernel-6.14.11-3-pve-signed: 6.14.11-3
proxmox-kernel-6.14.11-1-pve-signed: 6.14.11-1
proxmox-kernel-6.14.8-2-pve-signed: 6.14.8-2
amd64-microcode: 3.20251202.1~bpo13+1
ceph-fuse: 19.2.3-pve1
corosync: 3.1.10-pve1
criu: 4.1.1-1
dnsmasq: 2.91-1
frr-pythontools: 10.4.1-1+pve1
ifupdown2: 3.3.0-1+pmx12
ksm-control-daemon: 1.5-1
libjs-extjs: 7.0.0-5
libproxmox-acme-perl: 1.7.0
libproxmox-backup-qemu0: 2.0.2
libproxmox-rs-perl: 0.4.1
libpve-access-control: 9.0.5
libpve-apiclient-perl: 3.4.2
libpve-cluster-api-perl: 9.1.1
libpve-cluster-perl: 9.1.1
libpve-common-perl: 9.1.8
libpve-guest-common-perl: 6.0.2
libpve-http-server-perl: 6.0.5
libpve-network-perl: 1.2.5
libpve-rs-perl: 0.11.4
libpve-storage-perl: 9.1.0
libspice-server1: 0.15.2-1+b1
lvm2: 2.03.31-2+pmx1
lxc-pve: 6.0.5-4
lxcfs: 6.0.4-pve1
novnc-pve: 1.6.0-3
proxmox-backup-client: 4.1.4-1
proxmox-backup-file-restore: 4.1.4-1
proxmox-backup-restore-image: 1.0.0
proxmox-firewall: 1.2.1
proxmox-kernel-helper: 9.0.4
proxmox-mail-forward: 1.0.2
proxmox-mini-journalreader: 1.6
proxmox-offline-mirror-helper: 0.7.3
proxmox-widget-toolkit: 5.1.8
pve-cluster: 9.1.1
pve-container: 6.1.2
pve-docs: 9.1.2
pve-edk2-firmware: 4.2025.05-2
pve-esxi-import-tools: 1.0.1
pve-firewall: 6.0.4
pve-firmware: 3.18-1
pve-ha-manager: 5.1.1
pve-i18n: 3.6.6
pve-qemu-kvm: 10.1.2-7
pve-xtermjs: 5.5.0-3
qemu-server: 9.1.4
smartmontools: 7.4-pve1
spiceterm: 3.4.1
swtpm: 0.8.0+pve3
vncterm: 1.9.1
zfsutils-linux: 2.4.0-pve1

any ideas why it may have disappeared? any alternative to check arc stats other than the webui?

Edit: to those reading, apparently it's now called "zarcsummary" and "zarcstat", thanks to Onslow for the heads up!

 

[cheiss]

arc_summary is part of the zfsutils-linux package, which seems to be correctly installed.

What error do you get exactly when trying to run it?

 

[Onslow]

is this the result of an update?

Yes.
Now arc_summary is named zarcsummary .
And, BTW, arcstat is renamed zarcstat .

The details end explanation:

O

[SOLVED] Post in thread 'No zfstools in the latest kernel 6.17.9-1-pve'

Feb 5, 2026

At https://packages.debian.org/forky/amd64/zfsutils-linux/filelist I can see there are /usr/bin/zarcstat and /usr/bin/zarcsummary

Maybe those were renamed in the newer version?
What about man zarcstat ?

P.S.
Indeed.

https://metadata.ftp-master.debian.org/changelogs//contrib/z/zfs-linux/zfs-linux_2.4.0-1_changelog

zfs-linux (2.4.0-1~exp1) experimental; urgency=medium

* New upstream version 2.4.0.
...
* Rename arcstat and arc_summary to zarcstat and zarcsummary.
- no longer conflicts with nordugrid-arc-client (closes: #1063457).
-...

• Onslow

• 

 

[JakeFrosty]

arc_summary is part of the zfsutils-linux package, which seems to be correctly installed.

What error do you get exactly when trying to run it?

the command just doesn't exist, looks like an update finally removed the old command as Onslow said

 

[JakeFrosty]

Yes.
Now arc_summary is named zarcsummary .
And, BTW, arcstat is renamed zarcstat .

The details end explanation:

O

[SOLVED] Post in thread 'No zfstools in the latest kernel 6.17.9-1-pve'

Feb 5, 2026

At https://packages.debian.org/forky/amd64/zfsutils-linux/filelist I can see there are /usr/bin/zarcstat and /usr/bin/zarcsummary

Maybe those were renamed in the newer version?
What about man zarcstat ?

P.S.
Indeed.

https://metadata.ftp-master.debian.org/changelogs//contrib/z/zfs-linux/zfs-linux_2.4.0-1_changelog

zfs-linux (2.4.0-1~exp1) experimental; urgency=medium

* New upstream version 2.4.0.
...
* Rename arcstat and arc_summary to zarcstat and zarcsummary.
- no longer conflicts with nordugrid-arc-client (closes: #1063457).
-...

• Onslow

• 

Thanks for letting me know! that worked nicely
marking this as solved, cheers!