RAM questions

[mleopold]

hi,

i've read
http://www.freenas.org/hardware-requirements/
and
http://www.freenas.org/blog/a-compl...are-design-part-i-purpose-and-best-practices/

still i have a question:
does "1GB per TB of storage" apply to combined physical disk size or to available pool size after choosing the raid level?
when i have 16TB pool size with 4x8TB disks in RAID10 do i need 16GB or 32 GB RAM?

another question:
when i'm using freenas _exclusively_ for zvols to be served as iSCSI extents does this change anything about RAM requirements?

thx
matthias

 

[nojohnny101]

does "1GB per TB of storage" apply to combined physical disk size or to available pool size after choosing the raid level?

That rule of thumb is purposefully ambiguous because it is not meant to be a "hard and fast" rule. It is meant more of a guideline to follow that FreeNAS recommends for stable and tested operation.

when i have 16TB pool size with 4x8TB disks in RAID10 do i need 16GB or 32 GB RAM?

Note FreeNAS does not use RAID10, did you mean striped mirrors? In that case I would say start off with 16gb and then based upon how you observe performance to be, you can go from there.

I don't have any experience with iSCSI so I'll let someone else tackle that one.