Which drives to buy?

xenophon wrote:
To my mind, when it comes to upgrading HDs, there has to be some specific advice regarding the 4K-sector units. Are they compatible with sparc-based devices running the latest firmware but initialized with 512-byte blocks, in the 3.x Raidar era?

Don't confuse sector alignment of partitions with the block size of the volume. They are two separate things.

Also RAIDar is a client you can run on your Mac/Linux/Windows computer. I think you mean RAIDiator.

4k sector disks may have poor write performance if you didn't last factory reset on RAIDiator 4.1.7 or later to get 4k sector alignment. Whether the partitions on your disks are aligned for 4k sectors can be checked in partition.log.

There is a separate expansion limitation. If you last factory reset on RAIDiator 3.x, then your volume cannot expand past 5TB. You can check if you are affected by this limitation by looking at the block size of the volume.

Have a read of Why you might want to factory reset a Sparc ReadyNAS

xenophon wrote:

Say, for example, my RN Pro with 6 1-Tb drives is running the latest 4.2.19 beta firmware, but its volume log lists "Block size = 4096" because it was set up a couple of years ago. before FrontView 4.x. Can I autoexpand with 2Tb drives in the usual manner (i.e. replacing one by one)? Do they have to be 512-byte sector models? If I install a 4K sector unit (other than Western Digital) will I have to perform a system reset?

This is completely different to what you were talking about above. x86 ReadyNAS such as the Pro have Intel CPUs, and have completely different hardware to the Sparc ReadyNAS which have Infrant Sparc CPUs. The RAIDiator firmware was rewritten for x86 ReadyNAS. x86 ReadyNAS have always used RAIDiator 4.2.x. The volume has the standard 4k block size, performance is fine and there is no expansion limitation.

On x86 ReadyNAS, you should upgrade to 4.2.12 or later. Afterwards by swapping out the disks one by one (wait for resync to complete before swapping next disk) you will get 4k sector alignment.

Have a read of Why you might want to factory reset a x86 ReadyNAS