Pre-Build Questions

[BrennanK]

Howdy all. I have a few questions prior to my build. I am pretty familiar with servers and computers, but never done anything with this many drives. So the SAS Controllers and SAS back planes are all new to me.

I have a 3U 16 bay SuperMicro enclosure. It has a SuperMicro MoBo with dual quad core Xeons and 16GB of ram. I also have 12 1TB Hitachi Ultrastar drives.

What I want to do is have my 12 drives in a raidz2 and then eventually add 4 more drives in a different raid (using the other 4 bays).

What I still need is SAS controller to connect the 16 drives to the MoBo. From my research I have noticed that everyone around here is a big fan of the IBM ServeRaid M1015. My question is I found several different renditions of the M1015, does it matter? They are a little pricey when I need two of them to support 16 drives.

Questions
1. Can I have 2 different physical RAID arrays on the same box?
2. How does iSCSI work with FreeNAS, can I make a folder and use that as the target or does the whole array have to be the target? I want to use this for several different ESXi servers in addition to general media storage.
3. What are my options for controller cards?
4. How well does FreeNAS support HDD upgrades. Say I eventually want to change all the 1TB drives out for 4 TB drives. Do I need to offload all the data or can I do it sequentially?
5. How big of drives can I use with the M1015? Can I use a simple break out cable from the M1015's SFF-8087 to SATA connections on the back plane?
6. Do I need a dedicated OS drive or can I run FreeNAS off a flash drive?

Thanks for all the help with the new guy questions. I am sure I'll think of more...

Edit: added more questions

 

[cyberjock]

1. You shouldn't have any physical RAID arrays on your box if you are using ZFS.
2. You can do file based where you set a particular size.
3. Whatever you can find that does JBOD, and passes through SMART. There's other options if you really want to do the homework. But the M1015 is basically the best for the price and the best performing, not to mention 100% compatible. If I were in your shoes I'd just get an M1015 or two and not even look back. There's too much room for a newbie like you to get things wrong if you second guess the recommendations of the forum stickies. ;)
4. Read my presentation(link in my sig). That will answer that question and probably many others.
5. There is no limit currently. I think it's something like 64TB. You don't have to worry about any limit like the 2TB limit from years ago.
6. This is in the manual, a USB stick is recommended and preferred. Please check out the manual for exactly what recommendations are made for choosing the proper USB stick.