topic Re: FAS2020 Space issue in ONTAP Discussions

FAS2020 Space issue

markduffin — Thu, 05 Jun 2025 07:12:55 GMT

I have an issue with a FAS2020 with 12TB Sata drives in it.

There are 2 aggregates (agg0 and agg2)

They are configured

agg0 (RAID4) - 3 Disks - Total Space 707.66 GB

agg1 (RAID4) - 7 Disks - Total Space 4.15 TB

So just under 5TB for 10 available disks ? Does that sound right on RAID4 ?

Is there any way I can expand that ?

Re: FAS2020 Space issue

radek_kubka — Wed, 30 Jun 2010 11:16:51 GMT

Hi,

Just double-checking: is it a single controller setup?

If that's the case, I would create one large aggregate (disruptive for data in aggr1 as you have to destroy it!), use RAID-DP & leave either 2 hot-spares (that would enable background hard drive swap, should one of them be deemed 'dodgy' by disk maintenance feature), or one hot-spare if you are desperate for space.

With one hot-spare you should be looking at around 7TB of usable capacity.

Cheers,

Radek

Re: FAS2020 Space issue

eric_barlier — Wed, 30 Jun 2010 22:36:57 GMT

Hi,

We ve got smaller controllers interstate and we use

1 aggr.

raid 4

no aggr. snap reserve.

In your case you could migrate all into 1 aggr. delete the old aggr. and add those disks in the one remaining agrr. that ll give you more space, 1 disk and more IOPS

as well. that one aggr. with 3 disks will not perform much..

Eric

Re: FAS2020 Space issue

jherlihy1 — Thu, 01 Jul 2010 01:38:52 GMT

Hi,

Radek's on the money here - you would be better off creating a single RAID_DP aggregate with 11 x 1TB disks and leave 1 x hot spare. This would give you ~6.7TB usable capacity (with aggregate snap reserve set to 0).

I would recommend that you upgrade to ONTAP 7.3.3 (if not there already) as it will allow you to expand the aggregate past 7TB in the future without needing to leave a 2nd hot-spare (or have a separate root aggregate). This is a restriction with FAS2020s on ONTAP 7.3.x.

I would steer well clear of having 1TB disks in a RAID4 configuration - you can only have a max of 7 disks in each RAID4 raidset (so you would need to use a 2nd parity disk for the 2nd raidset anyway), and the long RAID rebuild time of a failed 1TB disk increases your risk of then having a double-disk failure while it's rebuilding. RAID_DP will protect you against a double-disk failure during a RAID rebuild.

Hope that helps.

Cheers,

John