Hi,
I have a new system using an LSI 9300 16i card with eight second hand 4tb drives, which all show 2.7tb in the storage ui.
Obviously something is wrong, has anyone else come across this before. The drives work and I created a pool but it’s a lot smaller than it should be.
I’m new to Truenas, any help or direct, things to check would be really appreciated. Thank you
We’d need more information on your setup, a list of drives with model(s), and how the pool was built.
At this stage, the only explanation I can think of is that a 3 TB drive is, or was, involved at some point.
Hi, thanks for your reply.
My system spec is:
Gigabyte B550 Gaming X V2
Amd ryzen 7 5700g
Yuanley 10g bate-t Ethernet card (intel x540)
LSI SAS 9300-16I HBA card
16g ram
256gb boot nvme ssd
500gb ssd for apps
Pool:
256gb cache
8x HGST 4tb SAS (12gb 7200rpm) label says 7814037168 sectors.
OK, really sorry to waste your time, I have found the issue, the drives are all model number : HUS72604CLAR3000 which are all 3tb drives.
Did they remove the stickers? Did they scratch the “3TB” on the label and write “4TB” with a marker. 
Good you figured out your issue.
But a cache device will give you no benefits with only 16GB of RAM. Actually it uses RAM itself reducing your relatively small amount even further.
Yes, that is generally correct.
However, their are rare cases where a Metadata only Cache / L2ARC device can help dramatically. Like backups to TrueNAS. Or massive reads of TrueNAS. Having the file’s Metadata in faster storage can make a difference.
