Forum Discussion

Aspirant

Apr 19, 2017

Solved

Volume useage exceeds 80% of size. When should I add another disk? RN104

I have 2x4TB in my RN104 with X-Raid (which means Raid-1 currently) If I understand X-Raid right adding a third disk will convert the whole thing into Raid 5 and I get more space while it protects f...

Adding Disks

mdgm-ntgr
Apr 19, 2017
dbrgzd wrote:

I have 2x4TB in my RN104 with X-Raid (which means Raid-1 currently)

If I understand X-Raid right adding a third disk will convert the whole thing into Raid 5 and I get more space while it protects from losing a single disk. (And later when this gets full adding 4th disk will just increase the capacity)

Yes

dbrgzd wrote:

I got the message that it's 80% full right now and planning to add the third disk. Is this process safe? Are there any dangers of losing my data while adding the third disk?

If one of the two disks already in the NAS fails during the resync you'd enter a data recovery attempt situation. So it's advisable to update your regular backup before adding a disk to expand your volume. You should backup your data regularly anyway.

dbrgzd wrote:

I am having firmware version 6.2.5.

At some point you should update the firmware using this workaround. 6.2.5 is extremely old firmware. I would suggest you update your regular backup before updating the firmware.

dbrgzd wrote:

Can I just hot plug the third disk? (same WD Red as the other 2)

Yes. You don't have to use the same disk model (though there are benefits to using the same model), but it does need to have at least as much capacity as the existing disks.

dbrgzd wrote:

I feel safer asking before doing anything.

Always much better to ask questions than to wish you had later.

dbrgzd

Aspirant

Apr 20, 2017

Thank you for the detailed answer.

How long can I wait to add the third disk? Is 80% already critical? 20% of 4TB is still a lot of space.

The reason I did not update is that I am afraid of risking the current stable state of the NAS. Considering I have a so old firmware I'm guessing that updating from where could cause problems either in the system or the data on the disks.

I might try that workaround if it is recommended to update. Of course after backing up to an external drive.

mdgm-ntgr

NETGEAR Employee Retired

Apr 20, 2017

I'd think 80% - should start to think about freeing up space or expanding the volume
85% - should really make the decision now

90% - should have already made the decision

This is my personal opinion. You can obviously fill it a little more than 85% if you want but things like performance will suffer and volume maintenance may not work well.

StephenB
Guru - Experienced User
Apr 20, 2017
mdgm wrote:

I'd think 80% - should start to think about freeing up space or expanding the volume
85% - should really make the decision now

90% - should have already made the decision

This is my personal opinion. You can obviously fill it a little more than 85% if you want but things like performance will suffer and volume maintenance may not work well.

I agree that you should be making the decision when fullness is in the 80-85% range. To some degree it depends on the growth rate. I think the risk is less if you have snapshots disabled.