Memory and raid types

[Patm]

I read that zfs needs lots of memory and that ufs should be used if you don't have it. The MB I'm using is limited to 8gig and I'm wondering if a total of 12 TB in drives on zfs can be handled by 8 gigs of ram ok?

I'm not really clear on the difference between running zfs and ufs or raidz1 and raid5. I was thinking raid 5 was the way to go before I found freenas - which would be the best way with these filesystems and raid types with 8 gig ram?

Thanks!

 

[kdon]

I believe that it is stated that "1GB RAM per TB of storage" is optimal. If you only have two dimm slots, can't you just get 2 8Gb sticks and call it a day? Choosing your raid setup is largely based on how many drives you have, and of what capacities they are, so you might want to add that information!

 

[Patm]

I have four slots but the MB can only see 8 gig. I did read the 1 gig/TB which is why I'm asking - there's got to be a point of diminishing returns. My setup is going to have five users max and most of the time that'll be 1 user accessing the nas with come periods where there may be 5.

I'm also not clear on whether its 1gig per TB of usable storage or per actual storage: 6TB in three drives or the 3.x TB you actually get as free space.

 

[b1ghen]

You will most likely be fine with 8GB if you don't do things like compression, deduplication or encryption.
If you don't have the RAM already it might actually be cheaper to upgrade to a newer platform though as buying old (not DDR3) RAM is quite a lot more expensive.

 

[Brand]

If you only have two dimm slots, can't you just get 2 8Gb sticks and call it a day?

Not if the motherboard doesn't support 2 x 8GB RAM modules.