Hi everyone,
This is strictly not a virtualization question, but a ZFS question, so I think that it'll be interesting for everyone involved with ZFS.
We have our ZFS-based backup server, which receives e.g. all dumps from our PVE cluster but also from other machines. The server is a HP DL 360G6, 72 GB-RAM, 96 GB L2ARC and three RAIDz2 vdevs consisting of 6 disks each, of which some are encrypted (others are in transition to be encrypted with LUKS).
Everything is fine and we monitor including performance metrics and here is the statistics from ARC and L2ARC. I am a little surprised. In our setup and use case, we almost never use L2ARC:
We have not tuned anything specially, so I'd like to know about experience of others regarding this.
In the near future, we will expand the main memory and drop the L2ARC completely.
This is strictly not a virtualization question, but a ZFS question, so I think that it'll be interesting for everyone involved with ZFS.
We have our ZFS-based backup server, which receives e.g. all dumps from our PVE cluster but also from other machines. The server is a HP DL 360G6, 72 GB-RAM, 96 GB L2ARC and three RAIDz2 vdevs consisting of 6 disks each, of which some are encrypted (others are in transition to be encrypted with LUKS).
Code:
root@backup ~ > zpool status -v rpool
pool: rpool
state: ONLINE
status: Some supported features are not enabled on the pool. The pool can
still be used, but some features are unavailable.
action: Enable all features using 'zpool upgrade'. Once this is done,
the pool may no longer be accessible by software that does not support
the features. See zpool-features(5) for details.
scan: scrub repaired 0B in 144h0m with 0 errors on Sat Dec 15 00:24:28 2018
config:
NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
raidz2-0 ONLINE 0 0 0
sdh ONLINE 0 0 0
sdm ONLINE 0 0 0
R2Z3S3_crypt ONLINE 0 0 0
sdj ONLINE 0 0 0
sdl2 ONLINE 0 0 0
R2Z2S1_crypt ONLINE 0 0 0
raidz2-1 ONLINE 0 0 0
sdn ONLINE 0 0 0
sdo1 ONLINE 0 0 0
R2Z1S2_crypt ONLINE 0 0 0
R2Z1S4_crypt ONLINE 0 0 0
sdr ONLINE 0 0 0
sds ONLINE 0 0 0
raidz2-2 ONLINE 0 0 0
R1Z1S2_crypt ONLINE 0 0 0
R1Z1S3_crypt ONLINE 0 0 0
R1Z2S2_crypt ONLINE 0 0 0
R1Z2S3_crypt ONLINE 0 0 0
R1Z3S2_crypt ONLINE 0 0 0
R1Z3S3_crypt ONLINE 0 0 0
cache
sdb1 ONLINE 0 0 0
errors: No known data errors
Everything is fine and we monitor including performance metrics and here is the statistics from ARC and L2ARC. I am a little surprised. In our setup and use case, we almost never use L2ARC:
We have not tuned anything specially, so I'd like to know about experience of others regarding this.
In the near future, we will expand the main memory and drop the L2ARC completely.