Questions on Mini XL+ hardware options

[rwv37]

I see that the Mini XL+ has two SSD ports, and it seems like in each you can put either (1) a "normal" SSD, (2) a read cache, or (3) a write cache. I imagine that a common build would be a read cache in one and a write cache in the other. Is there any advantage to putting a particular cache in the internal bay and the other particular cache in the external bay?

And I'm guessing that the configuration of these caches is pretty much automagical?

Finally, I think I know the answer to this one, but I just want to make sure: The "internal TrueNAS M.2 boot device" is not something that would count towards one of the two SSD bays, right?

Thanks in advance.

 

[HoneyBadger]

Hey @rwv37

To answer your questions in order:

Is there any advantage to putting a particular cache in the internal bay and the other particular cache in the external bay?

Only the inherent ease of serviceability by having the "external" bay be hot-swappable. Technologically, they are all connected to the same SATA controller on the motherboard of the Mini XL+ - some by breakouts, some by direct-attach - but each bay has its own 6Gbps lane. So no speed differences.

And I'm guessing that the configuration of these caches is pretty much automagical?

Mostly. They need to be added to the pool, either during initial creation or afterwards. The "write cache" (SLOG device) though will only be beneficial if your client systems either default to using synchronous writes (such as an NFS client) or are forced to do so by you choosing to set the "Sync" option in the TrueNAS UI to "Always" for the dataset or volume in question. This is usually only needed for writes that truly need to be immediately written to non-volatile storage, like a transactional database or a virtual machine disk on a remote hypervisor.

Finally, I think I know the answer to this one, but I just want to make sure: The "internal TrueNAS M.2 boot device" is not something that would count towards one of the two SSD bays, right?

Nailed it. The onboard M.2 boot device uses a PCIe x2 slot on the motherboard, and doesn't share any bays or lanes with the SATA drives.

Cheers!

 

[rwv37]

Thanks! One other question about something I just noticed, if you don't mind:

I have several WD Red Pro 22 TB drives (WD221KFGX) that I had been planning to put in another machine to replace existing drives. However, if I wind up getting a Mini XL+, I was thinking they might be of better use there. However, I just noticed the "Drive Compatibility List", and I see that while it lists several Red Pros, it stops at 18 TB.

I'm wondering if this means something like "Red Pro 22 TB will not work and/or will cause your house to explode", or more along the lines of "Well, we haven't officially tried out a Red Pro 22 TB"?

 

[rwv37]

Seemingly relevant to my own question: I just found a thread by someone who used these drives (though with a Mini R rather than a Mini XL+), and seemingly had no issues over the course of a month (I mean, "no further updates", not "and then it stopped working"), and was "very pleased".

 

[HoneyBadger]

Thanks! One other question about something I just noticed, if you don't mind:

I have several WD Red Pro 22 TB drives (WD221KFGX) that I had been planning to put in another machine to replace existing drives. However, if I wind up getting a Mini XL+, I was thinking they might be of better use there. However, I just noticed the "Drive Compatibility List", and I see that while it lists several Red Pros, it stops at 18 TB.

I'm wondering if this means something like "Red Pro 22 TB will not work and/or will cause your house to explode", or more along the lines of "Well, we haven't officially tried out a Red Pro 22 TB"?

The latter, as long as you don't find a way to use a Molex-to-SATA adapter

It'll work just fine as you found in the separate thread, and we're working the process of formally qualifying and adding the 22TB drives to our QVL and website configurator.

 

[rwv37]

Excellent - thanks again!