L2ARC devices should be striped, it does not matter if you lose one.

Mirroring the ZIL is not necessarily required either as writes are actually done from RAM, so unless you have a ZIL failure AND a system failure before the data can be flushed to disk, you won't lose anything.

That said, if you're only using a single 10Gbe connection you won't be able to use more than a single ZeusRAM worth of space anyway; with two 10Gbe links no more than two, so if this is one giant pool you might as well mirror them.

Thank you for your reply.

I was designing it off the TID from Nexenta from here: http://info.nexenta.com/rs/nexenta/images/techbriefnexenta_performance.pdf

In this doc they suggest that using:

1. (LOG) Striping mirrored SSD sets

2. (DATA POOL) Striping mirrored HDD sets

3. (LARC2) Striping SSD's

Nexenta mention this config as the best for using spindled HDD's in the main data pool. I also read somewhere to use 1-2GB memory for every 1TB in the storage pool. Not sure if this is still correct if not using dedupe, which I will not be.

The 10GbE card that I am using does have dual links, was thinking of using both as the switch I that I am now using for my storage network has multiple uplinks.

Cheers R

Yeah, mirrored ZILs are best, but they're not really required unless you absolutely cannot tolerate any chance of data loss, even remote.

If you're using dedupe you want a solid 4GB of RAM per TB of data for the dedup tables (not 4GB/1TB in general, the DDT isn't allowed to use all your ARC). All the people that did 1-2GB as the original recommendation was soon found their systems grinding to a halt when the started to get full or when they needed to commit a snapshot. Basically, dedup is a useless feature at the moment.

Ignoring dedup, you want as much RAM installed as your box can fit as it will be used for the ARC.

Hi,

I have no need for dedupe at the moment. Depending on money, I am also thinking of upping the memory from 96GB to 128GB as it is cheap at the moment :) The dual 2.66Ghz 6 Core processors should be able to keep the checksum'ing and compression in check.

I am hoping that the ZeusRAM drives will hide the 7200RPM drives from most of peak loads. The HDD's are SAS2 drives so I am hoping good things from them. So you where say that main memory will handle the initial write IO request and then dump the data to the HDD's?

Thank you for your great info. It is awesome to get feed back, esp when spending a decent amount money on storage.

Cheers R