Best solution for adding a shelf?

[adambaack]

I just wiped out a shelf in hopes of adding it to another shelf to create one big aggregate for performance and space needs.  From what I've seen, the way we had it setup is not the most ideal way (one aggregate per shelf).

I currently have these aggregates:

Aggr State           Status            Options
aggr0 online          raid_dp, aggr     root, nosnap=on, raidsize=18
aggr1 online          raid_dp, aggr     nosnap=on, raidsize=16
aggr2 online          raid_dp, aggr     nosnap=on, raidsize=12
aggr3 offline         raid_dp, aggr     raidsize=12

They're the DSM14K12 (think that's right)... the 14 drive SATA shelves.  What is the proper way to do this?  I see it says raidsize=12 in aggr2.  Does that mean if I try and combine the drives from aggr3 it will create another raidgroup?  Is this good or should I try and change the raid size first and then add the disks?  Is it better to have one big aggregate/raid size or one aggregate with two raids?

Sorry if I didn't say it right, still learning the NetApp stuff.

[adambaack]

Forgot to say...

This is on a FAS 2050 with each shelf being 14x750G SATA.

[aborzenkov]

Max raid group size for SATA disks is 16 (RAID_DP) with 14 being default. So there is no way to put two SATA shelves in one raid group. Depending on how much spare you want 14 or 13 would be fine IMHO (26 or 27 disks in two rg with 2 or 1 spare). If you already have spares available, go for 14 and two full shelves.

Keep in mind that max aggregate size on 7.x is 16TiB; this includes all disks in 7.2 and below and only data disks on 7.3. So look up disk size in storage management guide and compute max possible aggregate size based on it.

[adambaack]

I'm pretty sure this is incorrect, especially after looking at the table below.

[aborzenkov]

I'm pretty sure this is incorrect

Just curious, what exactly your this refers to.

[prakash_aviva]

Hi Adam,

Pls go through the table below. In your case, you need to go for raid group size 13 which results in 2 RGs with 4 parity disks .

Drive size	Drive type	Data ONTAP 7.2 and earlier	Data ONTAP 7.3
		Spindle Count	Number of Parity Disks	Optimal RAID Group Size	Resultant RAID Groups	Spindle Count	Number of Parity Disks	Optimal RAID Group Size	Resultant RAID Groups
36 GB	FC	427	66	15	32.87	493	66	17	32.88
72 GB	FC	212	28	16	15.00	246	42	14	20.57
144 GB	FC/SAS	106	16	16	7.63	123	18	16	8.81
300 GB	FC/SAS	51	8	15	3.93	61	10	15	4.73
250 GB	SATA	68	10	16	4.88	79	12	16	5.69
320 GB	SATA	53	10	13	4.85	61	10	15	4.73
500 GB	SATA	33	6	13	3.00	39	6	15	3.00
750 GB	SATA	22	4	13	2.00	26	4	15	2.00
1 TB	SATA	15	2	17	1.00	19	4	12	1.92