Need help to build a new server

[Proxipupuce]

Do not buy used PSUs unless you A) have the capability to ascertain their health or B) you have deep confidence the seller is not telling you bullshit. It takes very little to lose your system to a faulty PSU.

It's always hard to tell from photos alone whether the power supply is in good condition.

However, it has all its cables, is in its original box with its protective foams and manual, and the warranty label shows that it has never been dismantled.

I was attracted by the price, €90 instead of €140. Nevertheless, if it's safer to buy it new, then I'd buy it new, I don't want to risk losing my equipment.

 

[Davvo]

However, isn't it possible, on eight SATA ports, to connect the six new disks in RAIDZ2, and only two of the three disks in RAIDZ1 to copy the data? (In case I don't have any SSDs connected in SATA).

It is, but requires (at least) five new drives instead of just three. And is not the safest approach (but absolutely doable).

 

[Etorix]

However, isn't it possible, on eight SATA ports, to connect the six new disks in RAIDZ2, and only two of the three disks in RAIDZ1 to copy the data?

Yes. Or create the raidz2 pool, offline one drive, plug in the 3 raidz1 drives, copy your data (replication), remove the old pool, put back the sixth drive of the new pool and let it resilver.
Or attach the third drive of the raidz1 pool through a USB adapter while tranferring data.

 

[Proxipupuce]

Or attach the third drive of the raidz1 pool through a USB adapter while tranferring data.

Is it possible to do this? In my case, it would be really practical!

 

[Etorix]

It is advised NOT to use USB-attached drives as permanent members of a pool, but for a temporary operation it works, and full redundancy with one member drive on a somewhat dubious link is better than a degraded pool with one missing drive.