Storage Expansion Advice

svtspeed

Cadet
Joined
Dec 26, 2017
Messages
3
My build currently has 6x3TB SATA hdd's in RaidZ2 with all six drives connected through the SATA ports on the motherboard. I have recently purchased 6x3TB SAS hdd's and have them connected through an LSI HBA (P20 firmware) as there are no more available SATA ports on the motherboard. The SAS HBA seems to be functioning well; I ran badblocks on all drives connected to the HBA and then followed up with SMART long tests and had no issues or errors reported.

Now comes the time to utilize this new storage connected through the HBA. That is where I need some advice. Would it be good practice to expand my pool with the HBA connected drives, or would it be better to just create a new separate pool? I know that the point of FreeNAS is to be able to pool all your storage together, but I have some reservations about the HBA being somewhat of a single point of failure (e.g. if it goes for some reason it takes out 6 drives and the pool is gone). Am I overthinking when it comes to the HBA? I have never dealt with one before, so I don't know how generally reliable or stable they are. Again, I pounded on it with badblocks for about 28 hours without issue so I think it's good to go, but just wanted other opinions on the matter before I pull the trigger one way or the other. Thanks in advance for all replies!
 

blanchet

Guru
Joined
Apr 17, 2018
Messages
512
The most common failure in a server are hard disks and power supplies. LSI HBA are usually very reliable.
If the HBA fails, the pool will be unavailable until you purchase a new HBA. It is not different from a motherboard failure. So do not worry too much about that.
If you extend the pool to 2x 6-disks-raidZ2, you will increase the performance (more IOPS) and simplify the management (only one pool to manage)
Indeed, I see no special reason to create a second separated pool.

This video shows that a ZFS pool survives very well to a motherboard death:
 

svtspeed

Cadet
Joined
Dec 26, 2017
Messages
3
Awesome, thanks for the quick reply. That was just the sort of info I was looking for. The linked video was certainly a reassuring demonstration of resiliency from FreeNAS. I think that pretty much settles it for me in terms of my expansion plans; one pool it is!
 
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