Hardware raid vs ZFS based raid

[Leo David]

Hello,
I have a Dell PowerEdge with a PERC H730 Mini controller ( 12Gb/s and 1GB cache size ) that will allow me to create a mix of drives ( raid 1 for OS + rest of disks jbos)
The OS is installed on top of a raid1 array, and I intent to add 4 more enterprise grade data hdd's for creating a pbs datastore.
I do not have any spare dc-grade ssd to use as a caching layer in case of going with zfs

The question that I have regarding performance, best-practices, data availability, or easy future maintenance/replacement is:

Should i go for:

1. create a raid10 raid array at the Perc controller level and add this aray as a datastore ( directory ), and leaving the controller taking care of the things.
or
2. configure the data disks as jbods and create the raid array as a raid10 zfs pool

Any thoughts ?
Cheers,

Leo

 

[bobmc]

I think the general consensus is that ZFS + JBOD is not a good match, so option 1 would be the better choice.

Longer term, for future maintenance and flexibility, sourcing a decent non-raid controller would be your best option

 

[Leo David]

Thank you Bob,
But something is a bit confusing me in this case
"ZFS + JBOD is not a good match" - this controller can behave as a raid or jbod card as well in a mixed mode.It can have some disks in raid mode, and some disks as jbods. In case of configuring a disk as jbod it will be passing the disks directly to the OS, so acting as an hba card. Its just a matter of configuring the disks ( raid mode or jbod mode ).
So why zfs + jbod would not be a good match ? - in case of choosing option 2

 

[Kishi]

PERC H730 should have pass-through mode, so you should be able to just pass selected disks to the OS in (pass-through) HBA mode for ZFS.

 

[Leo David]

Thank you Kishi, you are right. So comming back to original question, what would be more appropiate, option 1, or option 2 ?
Thanks,

Leo

 

[bobmc]

Confusion of terminology here JBOD is a term that's been around for many years that indicates the controller is managing the device as a individual unit but that it was still not directly exposed to the OS, but at the same time I wasn't aware that the H730 could manage some devices as a raid controller and do device passthrough at the same time.

 

[Leo David]

Yes, Bob you are right.
I am sorry, my bad on this. "Pass-through" would be a more straight term.
So now that we decided the disks can also configured in pass-through mode as well, what would it be the best choice to go for ?
Excluding the disks health monitoring considerations that would involve different approaches.
Thank you,

Leo

 

[bobmc]

Personally, I would go with ZFS - primarily because it's platform agnostic. Should your existing controller/server fail you can move the drives to another system and still access the data

Then your choice becomes Raid10 or RaidZ2

 

[oversite]

Personally, I would go with ZFS - primarily because it's platform agnostic. Should your existing controller/server fail you can move the drives to another system and still access the data

Then your choice becomes Raid10 or RaidZ2

or zfs vdev mirrors, my fav

 

[Leo David]

Thank you,
In this case, by not having fast ssd's for caching layer to have a fast zfs pool, it might be better to benefit controller's 1gb cache and go for hw raid10.
Not much, but might add some performance.