READYNAS 104 drive expansion

---

jcs2000 wrote:

Can I pull one drive and install a larger drive (say 4TB or 6TB) and then get a data rebuild with access to the greater space?

  

---

No.  You'll need to install two drives of the larger size (one at a time).  The rule for capacity is "sum the disks and subtract the largest" That gives the same capacity with 4x3TB as it does with 3x3TB + 6 TB.

If you upgraded one drive to 6 TB, the system would resync, and the volume size won't change.  The extra space is unused.

When you upgrade the second 6 TB drive (after the resync), the system first resyncs again - with no expansion.  After a reboot, the volume will expand by 3 TB to 12 TB.  

When you upgrade the third, the system expands to 15 TB, and after you upgrade the last it expands to 18 TB.

I always suggest working out the $/TB delivered by the upgrade.

For instance,

With WD40EFRX replacements, upgrading to 4x4TB would gain 3 TB of space for about $450 (current US pricing)  that's $150/TB.

With WD60EFRX, upgrading to 4x6TB would gain 9 TB of space for $720.  That's only $80/TB.

With WD80EFZX, upgrading to 4x8TB would gain 15 TB of space for $1305.  that's $87/TB.

So right now, the most cost effective upgrade size for you is 6 TB.  You can choose something else of course, but it is useful to know what the optimal size is.