Replacing disks by larger ones

[RodeDraak]

Hi All,

I've just replaced a couple of 144GB disks on a FAS2050C (Data ONTAP 7.3.1) with 300GB disks. I just failed the 144GB disks and then replaced them with the 300GB ones.

When failing the disks the data moved to spares (also 300GB disks), but now not all space is usable. Is there a way to correct this?

Regards,

Richard.

[anthonyfeigl]

Hey Richard,

The filer will use the spares as like for like.

So 144 Data disks will be swapped with 144 regardless of size.

You would need to create a swing shelf or a swing volume and migrate data.

Than you can zero the disks and remove them.

Anthony

[tjlee]

Hi Richard,

You may want to look at this KB article which discusses this topic in detail.

https://now.netapp.com/Knowledgebase/solutionarea.asp?id=kb21090

Cheers, Tony

[RodeDraak]

So what I gather is that when a smaller disk gets replaced by a larger one the rest of the space is wasted.

Let me clarify on my situation. The system was delivered with the wrong disks (144GB instead of 300GB disks). 13 of the 20 disk could be replaced before the system was operational, the remaining 7 were delivered today and I had to replace them online (including the ones with ONTAP on them).

So now I'm stuck with 7 disks which cannot allocate the full capacity and from what I've gathered no way to get the space back.

So is there a way to reclaim the wasted space?

[anthonyfeigl · Accepted solution]

Yes Richard,

In my experience it will be easier to create swing volumes and migrate data.

I would suggest you work with the Pre Sales Engineer to get the extra disk/shelf you need to make it happen.

It is possible to make a copy of a shelf of data (as vols/aggrs) to a NEW shelf "bigger disks", pull one shelf out completely and modifiy the config with the filer so that the new shelf is recognized as the old vols.  Of course this will require business outage.

This would be done at the volume level and would entale renaming vols for filer access.  I last did this in 2005 so it has been a while, and I cannot remember the exact tech specs I took, but it is possible.  Again, the pre sales guys should be able to help you with this.

Anthony

[RodeDraak]

Alas, we do not have the means to get an extra shelf. So I'll guess we're stuck with wasted space.

[chriskranz]

What version of OnTap are you running?

This shouldn't really be the case (it used to be, but I was sure they changed it). You can mix disk sizes within an aggregate, and all space will be available, just the data will fill up unevenly. The only exception is with parity disks (if I remember correctly).

But if you could clarify the version of OnTap, and maybe post some outputs from the filer?

[RodeDraak]

Hi Chris,

As stated in my original post I'm running on ONTAP 7.3.1. And it was a brand new box, just delevired with the wrong disks (144GB instead of the ordered 300GB ones).

I was able to swap 13 disks before turning the box on, but 7 disks had to be replaced leter on, because they were not deliverd on time. So I did a disk fail for each of them and when that was complete, I swapped them for a 300GB disk. Now leaving me stuck with 7 disks not at full capacity.

But what I;ve gathered from what Anthony told me, it looks that this is normal behaviour.

Richard.

[amiller_1]

Yes, normal behavior although annoying in this circumstance (can be handy in the future when you can't get a certain size disk but can get a larger one as a spare)....I would reiterate the check with your Account Manager or SE idea as they should help make this right (i.e. not your fault the system was delivered with something other than what you ordered).