Mixing internal and external harddrives

[Pentarctagon]

The History:

I have Mint on my main PC, and several months back I decided ZFS sounded awesome and gave it a go using OpenZFS. I created a pool out of 3x2TB external hard drives, learned some of the basics, and it all went pretty well. Fast forward to today and I've managed to get FreeNAS installed and mostly setup with 4x2TB internal hard drives in raidz1.

The Problem:

I now have 3 2TB external hard drives sitting around and I don't know what to use them for anymore.

The Question:

Are there any good reasons not to plug in the external hard drives as well, and end up with 7x2TB disks?

The 4 internal drives as WD Reds and the external ones are 2 Seagate BUP Slim SLs and a WD My Passport 0748, so while the external ones probably do not have as good reliability, I could just set this up as a raidz3 and still end up with more usable storage space.

 

[mattbbpl]

Noooooooooo!

Don't do it. Pain will ensue.

There is a perfectly good use for those externals, though. Use them for a backup copy of your data. You want that anyway.

 

[Pentarctagon]

Noooooooooo!

Don't do it. Pain will ensue.

Could you be a bit more specific?

 

[mattbbpl]

Could you be a bit more specific?

You hit on one aspect yourself - drive reliability/quality.
Another aspect is speed. You'll be limiting your storage speed to that of the slowest drive in it.
More importantly though, the interface itself just causes low level havok in a multi-drive pool. We've had people come on here with similar setups who've said that their pool has been in a near constant state of resilvering for YEARS and they've finally given in. That's not a situation you want to put yourself into if you can help it.

Besides that, you really want a set of backup data anyway. That's a much better use of your drives rather than using them to increase the size beyond what you need at the expense of reliability and performance.

 

[Ericloewe]

You can also crack them open and remove the SATA drives inside and use them without the crap el-cheapo USB/SATA bridge. USB mass storage is often a glorious mess.

Beware of warranty concerns, though, and keep in mind that some bridges transparently encrypt drives (because... reasons...?), so the data may not be usable directly from the SATA interface.

 

[mattbbpl]

You can also crack them open and remove the SATA drives inside and use them without the crap el-cheapo USB/SATA bridge.

Yeah, that's a good idea if you really want to use these drives. Under heavy use, USB connections can be dropped or the controller can become locked. Removing the USB subsystem from the I/O chain would remove these concerns.

 

[Pentarctagon]

Huh, I did not know that. Neat. I'm not sure I trust myself to open them up without breaking them, but maybe something to try at some point in the future.

 

[Ericloewe]

Huh, I did not know that. Neat. I'm not sure I trust myself to open them up without breaking them, but maybe something to try at some point in the future.

Meh, if you don't care about the warranty and have little interest in using them as external drives, there's little you can screw up, if you apply common sense before brute force.

 

[gpsguy]

Just do a Google search for instructions/videos - https://www.google.com/search?q=youtube+shuck+hard+disk&ie=utf-8&oe=utf-8

I'm not sure I trust myself to open them up without breaking them