Using ZFS with Automatic Snapshots

readme.md

Using ZFS with Automatic Snapshots

ZFS References

• https://zfsonlinux.org/
• https://wiki.debian.org/ZFS
• https://openzfs.github.io/openzfs-docs/index.html
• https://openzfs.github.io/openzfs-docs/man/v2.3/8/zpool-create.8.html
• https://openzfs.github.io/openzfs-docs/man/v2.3/8/zfs-create.8.html
• https://openzfs.github.io/openzfs-docs/man/v2.3/7/zfsconcepts.7.html
• https://docs.freebsd.org/en/books/handbook/zfs/
• https://docs.oracle.com/cd/E26505_01/html/E37384/
• https://docs.oracle.com/cd/E19253-01/819-5461/gbchx/index.html

ZFS Tutorials:

• https://www.lambot.info/zfs-in-details/
• https://groupe-sii.github.io/cheat-sheets/openzfs/index.html
• https://www.cyberciti.biz/faq/installing-zfs-on-debian-12-bookworm-linux-apt-get/
• https://xai.sh/2018/08/27/zfs-incremental-backups.html
• https://www.high-availability.com/docs/ZFS-Tuning-Guide/#alignment-shift-ashiftn
• https://dannyda.com/2022/03/27/how-to-have-enable-automatic-zfs-pool-snapshot-in-linux-openmediavault-omv-debian-ubuntu-etc/

ZFS Snapshots Utils

• https://github.com/gbytedev/zfsbud
• https://github.com/zrepl/zrepl
• https://github.com/zfsonlinux/zfs-auto-snapshot
• https://github.com/bahamas10/zfs-prune-snapshots

Install ZFS (Zeta File System)

apt update
apt install linux-headers-amd64
apt install -t stable-backports zfsutils-linux
modprobe zfs
zfs version
zpool -h

List devices

lsblk
fdisk -l

unmount disk to format in ZFS ( if necesary )

vi /etc/fstab 
umount /disco2

Create the pool on one disk

zpool create -f -d -m none -o ashift=12 -O atime=off -o feature@lz4_compress=enabled pool1 /dev/nvme1n1

zpool create <options> <poolname> <vdevices...>

-f                  
Forces use of vdevs, even if they appear in use or specify a conflicting replication level. Not all devices can be overridden in this manner.

-d                  
 Do not enable any features on the new pool. Individual features can be enabled by setting their corresponding properties to enabled with -o. See zpool-features(7) for details about feature properties.
 
-m mountpoint       
Sets the mount point for the root dataset. The default mount point is /pool or altroot/pool if altroot is specified. The mount point must be an absolute path, legacy, or none. For more information on dataset mount points, see zfsprops(7).
 
-o property=value   
 Sets the given pool properties. See zpoolprops(7) for a list of valid properties that can be set.

-o feature@feature=value
Sets the given pool feature. See the zpool-features(7) section for a list of valid features that can be set. Value can be either disabled or enabled.

-O file-system-property=value  
Sets the given file system properties in the root file system of the pool. See zfsprops(7) for a list of valid properties that can be set.

Some Settings:
ashift	12	4KiB block size
recordsize	128Kib	Standard usage (mixture of file sizes)
atime   Keeps a trace of the files access time, which is of no use. You can disable it with:
compression feature, when enabled, compresses data before it is written out to disk (as the copy-on-write nature of ZFS makes it easier to offer inline compression).
Default compression (currently lz4)

zpool commands

zpool list
zpool status

Create the file system "vmsdisk" on "pool1" and set the mount point

zfs create pool1/vmsdisks
zfs set mountpoint=/vmsdisks pool1/vmsdisks

Now... the file system is ready to be used !!!!

Get some information about the file system

zfs get compression
zfs get atime
zfs get mountpoint
mount | grep zfs
zfs list -t all
cat /etc/default/zfs

Automatic snapshots using zfsbud

# https://github.com/gbytedev/zfsbud
#


# Download zfsbud.sh, make it executable, configure it
cd /root
wget https://raw.githubusercontent.com/gbytedev/zfsbud/refs/heads/master/zfsbud.sh
chmod +x zfsbud.sh 
wget https://raw.githubusercontent.com/gbytedev/zfsbud/refs/heads/master/default.zfsbud.conf
mv default.zfsbud.conf zfsbud.conf

# How to configure ZFSBud
vi zfsbud.conf 

# Snapshot retention policy
# Apart from the below, the last snapshot is always kept, as well as the most recent common snapshot (in case the `--send|-s` flag is passed).
# The number of hourly snapshots to keep (one per hour, starting with this hour and going backward).
hourly=20
# The number of daily snapshots to keep.
daily=10
# The number of weekly (Sunday) snapshots to keep.
weekly=4
# The number of snapshots of first sundays of every month to keep.
monthly=0
# The number of snapshots of first sundays of the year to keep.
yearly=0
# Other settings
# This can be overriden during runtime with --snapshot-prefix|-p
# Change this to adjust to your servername or dataset name
default_snapshot_prefix=myservername_

add task to cron

crontab -e
# take a snapshot every 10 minutes, remove old ones, keep newest acording to /root/zfsbud.conf
*/10 * * * * /root/zfsbud.sh  --create-snapshot --remove-old pool1/vmsdisks

List snapshots

zfs list -t all

zpool commands

zpool status
zpool list
zpool iostat
zpool history

# zpool example commands
root@server:~# zpool status
  pool: pool1
 state: ONLINE
  scan: scrub repaired 0B in 00:08:21 with 0 errors on Sun Feb  9 00:32:22 2025
config:

	NAME        STATE     READ WRITE CKSUM
	pool1       ONLINE       0     0     0
	  nvme1n1   ONLINE       0     0     0

errors: No known data errors

root@server:~# zpool list
NAME    SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
pool1   416G   255G   161G        -         -    50%    61%  1.00x    ONLINE  -


root@server:~# zpool iostat
              capacity     operations     bandwidth 
pool        alloc   free   read  write   read  write
----------  -----  -----  -----  -----  -----  -----
pool1        255G   161G      5     43   481K  1.23M