Awhile back I acquired a 240GB Seagate 600 Pro to play around with l2arc and slog on my FreeNAS box. Most of the time I use the box just as a home media server, but I occasionally use it as an iSCSI target for a hyper-v host. I wasn't really concerned about performance, just wanting to learn.
Yesterday I was looking at the reporting tab in the WebGUI and noticed that it was reporting my l2arc size as over 80GB. This is strange to me because the size of the partition is only 40GB. I added the partition using the UUID following this guide: https://clinta.github.io/FreeNAS-Multipurpose-SSD/
My FreeNAS box: latest 9.3.1
AMD FX 8320 underclocked/undervolted
Asus Crosshair V Formula-Z
32GB Crucial ECC (4x8gb DDR3L UDIMM)
M1015 P20 firmware
HP SAS Expander
Norco 4220
Seagate 600 Pro 240gb (attached to motherboard SATA port)
Output of ./arcstat.py -f l2size:
Output of gpart show ada0:
I did see a post on the FreeNAS forums dating back to 9.1 where someone had noted a similar error, but there was no resolution beyond the typical insults and discussion about how improperly sized his l2arc was. There was some thought that perhaps the l2arc stats were reflecting compression but that was deemed to be inaccurate in 9.1.x, and the command suggested to check for the actual size (arcstat.py -f l2asize) also does not work in 9.3.1.
Apologies if this comes up elsewhere, I've done about an hour of googling and found nothing.
I guess my main/only question: is this something I should be concerned about, or is this just normal behavior? I don't really have any need for the cache/log device with my current usecase.
Yesterday I was looking at the reporting tab in the WebGUI and noticed that it was reporting my l2arc size as over 80GB. This is strange to me because the size of the partition is only 40GB. I added the partition using the UUID following this guide: https://clinta.github.io/FreeNAS-Multipurpose-SSD/
My FreeNAS box: latest 9.3.1
AMD FX 8320 underclocked/undervolted
Asus Crosshair V Formula-Z
32GB Crucial ECC (4x8gb DDR3L UDIMM)
M1015 P20 firmware
HP SAS Expander
Norco 4220
Seagate 600 Pro 240gb (attached to motherboard SATA port)
40GB partition for l2arc
12GB partition for slog
12x Seagate 4TB NAS hdd12GB partition for slog
(2 six disk RAIDZ2 vdevs in one pool)
lz4 compression is enabled on the pool, but it is mostly incompressible data (video, music, pictures)Output of ./arcstat.py -f l2size:
Code:
l2size 89G
Output of gpart show ada0:
Code:
34 468862061 ada0 GPT (223G) 34 94 - free - (47k) 128 25165824 1 freebsd-zfs (12G) 25165952 83886080 2 freebsd-zfs (40G) 109052032 359810063 - free - (171G)
I did see a post on the FreeNAS forums dating back to 9.1 where someone had noted a similar error, but there was no resolution beyond the typical insults and discussion about how improperly sized his l2arc was. There was some thought that perhaps the l2arc stats were reflecting compression but that was deemed to be inaccurate in 9.1.x, and the command suggested to check for the actual size (arcstat.py -f l2asize) also does not work in 9.3.1.
Apologies if this comes up elsewhere, I've done about an hour of googling and found nothing.
I guess my main/only question: is this something I should be concerned about, or is this just normal behavior? I don't really have any need for the cache/log device with my current usecase.
