====== ZFS ======
  * https://wiki.archlinux.org/index.php/Install_Arch_Linux_on_ZFS
  * https://openzfs.github.io/openzfs-docs/Getting%20Started/Ubuntu/Ubuntu%2020.04%20Root%20on%20ZFS.html
  * https://www.usenix.org/system/files/login/articles/login_winter16_09_jude.pdf
  * https://bigstep.com/blog/zfs-best-practices-and-caveats
  * https://docs.oracle.com/cd/E19253-01/819-5461/6n7ht6qvi/index.html
  * https://docs.oracle.com/cd/E19253-01/819-5461/gammr/index.html
  * https://unixlinux.tmit.bme.hu/ZFS


===== Quota =====
  * https://docs.oracle.com/cd/E23823_01/html/819-5461/gazvb.html
    
    
===== Snapshotok =====
  * https://docs.oracle.com/cd/E23824_01/html/821-1448/gbciq.html
  * https://serverfault.com/questions/855895/how-to-set-the-number-of-snapshots-zfs-auto-snapshot-should-retain
    
    
===== Teljesítmény javítás =====
  * https://icesquare.com/wordpress/how-to-improve-zfs-performance


===== Cache =====
  * https://linuxhint.com/configuring-zfs-cache/
  * https://www-45drives-com.translate.goog/community/articles/zfs-caching/?_x_tr_sl=auto&_x_tr_tl=hu&_x_tr_hl=en-US&_x_tr_pto=op
  * https://linuxhint.com/configure-zfs-cache-high-speed-io/


===== Replikálás =====
  * https://docs.oracle.com/cd/E69294_01/html/E69466/gplkt.html#GEZSNgqnsz

<code bash>
# For example, on a system containing a ZFS dataset name src, the following command transfers the snapshot to the dataset hierarchy at dst on the target system.
zfs send -R src_data_pool@TOSNAP | ssh 'target-machine' zfs receive -F dst_data_pool

# If the above command is interrupted, type the following command to resume the interrupted transfer.
ssh 'target-machine' zfs receive -C dst_data_pool | zfs send -RC src_data_pool@TOSNAP | ssh 'target-machine' zfs receive -F dst_data_pool
</code>
===== Mirror bővítése =====
  * https://www.unixarena.com/2013/07/zfs-how-to-extend-zpool-and-re-layout.html/

<code bash>
zpool add \
    data_pool \
    mirror \
    /dev/disk/by-id/ata-WDC_WD20EZAZ-00L9GB0_WD-WXW2AA046VL5-part1 \
    /dev/disk/by-id/ata-WDC_WD20EZAZ-00GGJB0_WD-WXJ2A9058FDS-part1
</code>


===== Hibás lemez cseréje =====
  * https://docs.oracle.com/cd/E19253-01/819-5461/gbcet/index.html
  * https://www.dlford.io/linux-zfs-raid-disk-replacement-procedure/

  - Jelenlegi pool állapotának lekérdezése: <code bash>
zpool status -stv
</code><code>
  pool: backup_pool
 state: DEGRADED
status: One or more devices has experienced an error resulting in data
        corruption.  Applications may be affected.
action: Restore the file in question if possible.  Otherwise restore the
        entire pool from backup.
   see: http://zfsonlinux.org/msg/ZFS-8000-8A
  scan: scrub repaired 212K in 0 days 03:44:08 with 34 errors on Wed Nov 10 04:55:23 2021
config:

        NAME                                              STATE     READ WRITE CKSUM  SLOW
        backup_pool                                       DEGRADED     0     0     0     -
          ata-WDC_WD60EZRZ-00GZ5B1_WD-WX31D96RP4EP-part1  DEGRADED     0     0     0     0  too many errors  (trim unsupported)

errors: Permanent errors have been detected in the following files:

        backup_pool/restic:/data/3e/3eac085714f593e3ada48aa88b562eecae09dfab1d0ab2120b006a8662a57d2b
        backup_pool/restic:/data/2e/2ed3eb09103030fd890a8a4df23b44e274170a5fd0fedad0710ebc51df312aab
        backup_pool/restic:/data/1e/1eea1754cf4fd2cc66cf3881dcb4d22418a0e227c903ed642346d7b5852e5f5d
        backup_pool/restic:/data/0e/0e6af1fa3c4a6624f5d712b91cedac382099d777d1e44f06ec54671e547bd5e5
        backup_pool/restic:/data/62/62ea5d8ff86019b607bfb1c826c462888c8122fc26a20b24ebb8f7529cce2746
        backup_pool/restic:/data/b7/b7603740916f2f1deec3dd05f0037a5bcfa2d27b36d5c9701baa9d2f7c926411
        backup_pool/restic:/data/bd/bddfcea36cb9d732c688d3f3dff2b5fb98d553efc0a690ece16729e5b6d06b33
</code>
  - Lemezcsere indítása: <code bash>
zpool replace <pool> <hibás_lemez> /dev/disk/by-id/<új_lemez>
# zpool replace backup_pool ata-WDC_WD60EZRZ-00GZ5B1_WD-WX31D96RP4EP-part1 /dev/disk/by-id/ata-WDC_WD60EZAZ-00SF3B0_WD-WX22D51FH5N3-part1
</code>



===== Partíció bővítés =====
  * https://forums.freebsd.org/threads/extend-zfs-partition.55964/
  * https://serverfault.com/questions/946055/increase-the-zfs-partition-to-use-the-entire-disk

  - Automatikus pool kiterjesztés bekapcsolása: <code bash>
zpool set autoexpand=on <zpool_name>
</code>
  - Partíció / LVM logikai kötet kiterjesztése: <code bash>
lvextend -L 700G /dev/<lvm_group>/<lvm_volume>
# vagy
lvextend -L +100G /dev/<lvm_group>/<lvm_volume>
</code>
  - Opcionális: ayutomatikus pool kiterjesztés kikapcsolása: <code bash>
zpool set autoexpand=off <zpool_name>
</code>


===== TRIM-elés =====
<code bash>
zpool trim private_pool my_private
</code>