ZFS install on a partition

[Ivailo Tanusheff]

Hi,

If you use HBA/JBOD then you will rely on the software RAID of the ZFS system. Yes, this RAID is good, but unless you use SSD disks to boost performance and a lot of RAM the hardware raid should be more reliable and mush faster.
I didn't get if you want to use the system to dual boot Linux/FreeBSD or just to share FreeBSD space with linux.
But I would advise you to go with option 1 - you will get most of the system and obviously you don't need zpool with raid, as your LSI controller will do all the redundancy for you. Making software RAID over the hardware one will only decrease performance and will NOT increase the reliability, as you will not be sure which information is stored on which physical disk.

If stability is a MUST, then I will also advise you to go with bunch of pools and a disk designated as hot spare - in case some disk dies you will rely on the automation recovery. Also you should run monitoring tool on your raid controller.
You can also set copies=2/3 just in case some errors occur, so ZFS can auto0repair the data. if you run ZFS over several LUNs this will make even more sense. 

Best regards,
Ivailo Tanusheff

-----Original Message-----
From: owner-freebsd-questions at freebsd.org [mailto:owner-freebsd-questions at freebsd.org] On Behalf Of bsd at todoo.biz
Sent: Saturday, May 18, 2013 1:24 AM
To: Liste FreeBSD
Subject: ZFS install on a partition

Hi, 

I have a question regarding ZFS install on a system setup using an Intel Modular. 

This system runs various flavor of FreeBSD and Linux using a shared pool (LUNs). 
These LUNs have been configured in RAID 6 using the internal controller (LSI logic). 

So from the OS point of view there is just a volume available. 


I know I should install a system using HBA and JBOD configuration - but unfortunately this is not an option for this server. 

What would you advise ? 

1. Can I use an existing partition and setup ZFS on this partition using a standard Zpool (no RAID). 

2. Should I use any other solution in order to setup this (like full ZFS install on disk using the entire pool with ZFS). 

3. Should I avoid using ZFS since my system is not well tuned and It would be asking for trouble to use ZFS in these conditions. 


P.S. Stability is a must for this system - so I won't die if you answer "3" and tell me to keep on using UFS. 


Thanks.