linux – Mario

ZFS diff since last snapshot

Posted on 02.05.2026 by mario

Just a quick bash script

SNAP=backup-zfs_2026-04-24_10:34:38
POOL=tank

zfs list -H -o name -r $POOL | while read ds; do
  if zfs list -H -t snapshot ${ds}@${SNAP} >/dev/null 2>&1; then
    echo "[DATASET] $ds"
    zfs diff ${ds}@${SNAP}
  fi
done

pg 2.b not deep-scrubbed since…

Posted on 13.03.2026 by mario

With the ceph update that I nade to 19.2.3 I got warnings like

pg 2.b not deep-scrubbed since 2026-02-27T00:56:11.986819+0100
pg 2.fa not deep-scrubbed since 2026-02-27T05:32:34.264221+0100

It seems that sometimes the nightly deepscrub window is too short. I don#t like warnings in the dashboard from my proxmox cluster.
So I started to deep scrub that placement group (PG) on demand during buisness hours :D

ceph pg deep-scrub 2.b

I have 2048 PGs over 48 OSDs each 8 TiB. it took 20 Minutes to complete that one PG.

Ip bringing Interfaces Up Down

Posted on 07.03.202507.01.2025 by mario

using ip

# ip link set dev <interface> down
ip link set dev eth0 down
# ip link set dev <interface> up
ip link set dev eth0 up

using ipconfig

# /sbin/ifconfig <interface> up
# /sbin/ifconfig <interface> down

Ceph Reset Error

Posted on 07.01.2025 by mario

Display a list of messages:

ceph crash ls

read a message:

ceph crash info <id>

mark message as read

ceph crash archive <id>

or mark all as read

ceph crash archive-all

proxmox “/usr/sbin/proxmox-boot-tool not found”

Posted on 04.04.2024 by mario

That is a pretty annoying error message. To get rid of it

apt install pve-kernel-helper

zfs snapshot sort by size

Posted on 30.12.2023 by mario

When you see your zpool exploding, but the “used” size isn’t that much, you may take a look at your snaphosts.

First find the dataset with the that has the largest snapshot

zfs list -o name,usedbysnapshots | sort -r -k2

example output

tank/mails                                  56.3G
tank/store                                   261M
tank/docker                                 2.38M

In this case the tank/mails dataset should be looked at.

Snapshots can then be listed for that filesystem by using a command

# zfs list -t snapshot -r 
zfs list -t snapshot -r tank/mails

ZFS Pool extended Status

Posted on 28.12.202328.12.2023 by mario

Some commands for extended zpool status

ZPOOL_SCRIPTS_AS_ROOT=1 zpool status -c health
ZPOOL_SCRIPTS_AS_ROOT=1 zpool status -c hours_on
ZPOOL_SCRIPTS_AS_ROOT=1 zpool status -c lsblk
ZPOOL_SCRIPTS_AS_ROOT=1 zpool status -c smart_test
ZPOOL_SCRIPTS_AS_ROOT=1 zpool status -c temp
ZPOOL_SCRIPTS_AS_ROOT=1 zpool status -c upath

ceph scrubbing time

Posted on 27.07.2023 by mario

When you don’t scrub your ceph pool it will scrub itself when you don’t want it to scrub: during working hours. To avoid that you can set the time in the night when scrubbing is allowed

the ceph config set is global for the cluster / all nodes.

root@pve-01:/etc/ceph# ceph config get osd osd_scrub_begin_hour
0
root@pve-01:/etc/ceph# ceph config set osd osd_scrub_begin_hour 22
root@pve-01:/etc/ceph# ceph config get osd osd_scrub_begin_hour
22
root@pve-01:/etc/ceph# ceph config get osd osd_scrub_end_hour
0
root@pve-01:/etc/ceph# ceph config set osd osd_scrub_end_hour 7
root@pve-01:/etc/ceph# ceph config get osd osd_scrub_end_hour
7
root@pve-01:/etc/ceph#

Linux mount domain SMB / cifs

Posted on 04.05.202304.05.2023 by mario

sudo mount -t cifs -o user=dummy,domain=example.local,uid=$(id -u),gid=$(id -g),forceuid,forcegid,vers=2.0 //files.example.local/share ~/P

ZFS rename disk path

Posted on 19.04.2023 by mario

zpool status
  pool: tank
 state: ONLINE
config:

        NAME                                          STATE     READ WRITE CKSUM
        tank                                          ONLINE       0     0     0
          mirror-0                                    ONLINE       0     0     0
            usb-SanDisk_SDSSDA-1T00_0123456789CA-0:0  ONLINE       0     0     0
            da3p4                                     ONLINE       0     0     0

errors: No known data errors

zpool set path=/dev/disk-by-id/sdsdsdsd tank da3p4
zpool set path=/dev/gpt/my_nice_name

just type `zpool import` and you will see the name that you can import.

if you want to change the mount path use

zpool import -R /other/path poolname

to rename the pool use

zpool import original_name new_name

Tag: linux