ZFS

Notes on ZFS

Home setup

On osx I'm running a bunch of 12tb disks in a raidz2 config. My intent is to migrate to a zpool with special devices in it.

Plan is 20 12tb disks in 2 vdev's of raidz2 with 3.2 TB SSD's in a mirror. I'll use the m2 SSD on the server for ZIL and l2arc.

This should give about 174.56 TiB of space.

Optimization

All disks should be updated

./SeaChest_Firmware_x86_64-redhat-linux --downloadFW /root/MobulaExosX12SAS-STD-5xxE-E004.LOD  -d /dev/sg7

All disks should be 4k sectors. The spinning disks should be long formatted to detect bad blocks.

./SeaChest_Lite_x86_64-redhat-linux  --setSectorSize 4096 --confirm this-will-erase-data -d /dev/sg8

Write cache should be enabled:

# sdparm --get=WCE /dev/sg5
    /dev/sg5: SEAGATE   ST12000NM0027     E004
WCE           0  [cha: y, def:  1, sav:  0]

# sdparm --set=WCE --save /dev/sg5                                                                                         |
    /dev/sg5: SEAGATE   ST12000NM0027     E004

# sdparm --get=WCE --save /dev/sg5
    /dev/sg5: SEAGATE   ST12000NM0027     E004
WCE           1  [cha: y, def:  1, sav:  1]

ashift= 13 = 8192 byte per IO.
recordsize             256K
compression            lz4
casesensitivity        insensitive
special_small_blocks   128K

zdb -Lbbb  PoolName

zpool create -f -o ashift=12 -O casesensitivity=insensitive -O normalization=formD -O compression=lz4 -O atime=off -O recordsize=256k ZfsMediaPool \
raidz2 /var/run/disk/by-path/PCI0@0-SAT0@17-PRT5@5-PMP@0-@0:0 /var/run/disk/by-path/PCI0@0-SAT0@17-PRT4@4-PMP@0-@0:0 \
/var/run/disk/by-path/PCI0@0-RP21@1B,4-PXSX@0-PRT31@1f-PMP@0-@0:0 /var/run/disk/by-path/PCI0@0-SAT0@17-PRT3@3-PMP@0-@0:0 \
/var/run/disk/by-path/PCI0@0-SAT0@17-PRT2@2-PMP@0-@0:0 /var/run/disk/by-path/PCI0@0-SAT0@17-PRT1@1-PMP@0-@0:0 \
/var/run/disk/by-path/PCI0@0-SAT0@17-PRT0@0-PMP@0-@0:0 /var/run/disk/by-path/PCI0@0-RP21@1B,4-PXSX@0-PRT2@2-PMP@0-@0:0 \
/var/run/disk/by-path/PCI0@0-RP21@1B,4-PXSX@0-PRT3@3-PMP@0-@0:0 /var/run/disk/by-path/PCI0@0-RP21@1B,4-PXSX@0-PRT28@1c-PMP@0-@0:0 \ 
/var/run/disk/by-path/PCI0@0-RP21@1B,4-PXSX@0-PRT4@4-PMP@0-@0:0 /var/run/disk/by-path/PCI0@0-RP21@1B,4-PXSX@0-PRT29@1d-PMP@0-@0:0

zpool add ZfsMediaPool log /dev/disk5s3
zpool add ZfsMediaPool cache /dev/disk5s4

=

https://github.com/openzfs/zfs/discussions/12769