3 drives best setup -phantom?

[LaurenceL]

Hi. I have 3 drives connected to sata ports and my boot up ssd connected to sas port.
when I go to create a pool I only see options stripe,mirror and raids not raidz2, is this correct?
I may have another drive coming but not sure where I’m going to plug it in yet. I have seen some discussion about creating a phantom drive until it arrives. How does that work?
if I decide to stick with 3 drives what is my best option? 2 drives striped and use the third to create a back up everyday?
my System is a prehistoric dell precision 690 but it was cheap and enough to get me started.
this leads on to another question about booting up, my boot up ssd is plugged into a sas port so I have to press f12 and select it as the boot disk every time I turn it on. What are my options? May be a pci-e card with more sata connectors?
Tia

 

[sretalla]

3 drives
raidz2, is this correct?

I had understood that the minimum drive count for a RAIDZ2 VDEV was 4.

If you want 1 data disk and 2 "parity" disks, use a 3-way mirror.

 

[danb35]

I had understood that the minimum drive count for a RAIDZ2 VDEV was 4.

That's correct. For any form of parity RAID, it's a minimum of two disks plus parity (so three for RAIDZ1, four for RAIDZ2, five for RAIDZ3).

 

[sretalla]

I have seen some discussion about creating a phantom drive until it arrives. How does that work?

Creating a degraded pool

danb35 submitted a new resource: Creating a degraded pool - Creating an intentionally-degraded pool to allow for later expansion/redundancy WARNING: HERE BE DRAGONS. IF YOU DON'T KNOW EXACTLY WHAT YOU'RE DOING, DO NOT FOLLOW THESE INSTRUCTIONS. IN FACT, IF YOU NEED THESE INSTRUCTIONS, YOU...

www.truenas.com

I would not recommend doing that with data you care about.

 

[LaurenceL]

Ok so I need to get the fourth disk. I will then have to plug them all into the sas ports on the mobo. When I boot up I have the option of going into the sas controller. Can I go into this controller and turn off any raid options it may give me as I want Freenas to look after that?

 

[sretalla]

Can I go into this controller and turn off any raid options it may give me as I want Freenas to look after that?

What's all the noise about HBA's, and why can't I use a RAID controller?

This is relevant to FreeNAS and TrueNAS CORE. Some parts of it might also be relevant to Scale, but I don't really know how reliable the Linux drivers are. 1) An HBA is a Host Bus Adapter. This is a controller that allows SAS and SATA devices to be attached to, and communicate directly with...

www.truenas.com

If it's just a SAS controller with no RAID chip involved, fine, but read the above thread in any case.

 

[LaurenceL]

What's all the noise about HBA's, and why can't I use a RAID controller?

This is relevant to FreeNAS and TrueNAS CORE. Some parts of it might also be relevant to Scale, but I don't really know how reliable the Linux drivers are. 1) An HBA is a Host Bus Adapter. This is a controller that allows SAS and SATA devices to be attached to, and communicate directly with...

www.truenas.com

If it's just a SAS controller with no RAID chip involved, fine, but read the above thread in any case.

It can do raid 0 or 1

 

[danb35]

What controller are you using?

 

[LaurenceL]

It says LSI logic config utility for dell sas 5 v6
I see options to change boot up in the menu; disabled, boot os, boot bios, boot os and bios.
I want the controller to see the hard drives but not raid them. Will try in the morning