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vnx2 with 7 FAST VP disks
Hello,
we have a VNX2 comes with 7x400GB (3.5") FAST VP drives. and multiple SAS and NL-SAS drives.
the storage array consists of : 1x3UxDPE(25x2.5") + 4x3UxDAE(15x3.5") as follows:
DAE#4 : Bus 0 Enc 2
DAE#3 : Bus 1 Enc 1
DAE#2 : Bus 0 Enc 1
DAE#1 : Bus 1 Enc 0
DPE#1 : Bus 0 Enc 0
could you please share with me your thoughts about the best way to be used to place the FAST VP drives ??
should i distribute the FAST VP across Buses/Enclosures ?? should i place all the Disks of the raid group set within the same bus/enclosure?
Please consider one disk as a hot spare in addition what type of raid can be applied on 6 FAST VP disks ??
Many Thanks,
brettesinclair
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February 16th, 2015 02:00
Yes, you should be able to choose 5+1 for your Extreme Capacity tier, with the considerations in my first post.
2 spares for that amount of drives is expensive in resource (capacity) and $$.
Placement of drives is not really important with drive mobility and permanent sparing in the VNX2, so I would put them in the same DAE just for 'neatness'.
brettesinclair
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715 Posts
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February 15th, 2015 19:00
For only 7 flash disks I'd put them in same DAE, in order. No benefit/point in splitting over DAE's and BUS's in a small config like this. Are you making one big pool of all the disks ?
You can attempt to add a tier as RAID5 5+1 (I've only ever created 4+1 as per best practice) and 1 will be assigned as a spare by policy.
Change the disk selection for the new pool to Manual and choose the disks you want to use.
If a 5+1 is not permitted (you'll see an invalid disk selection displayed in the number of flash disks box).
Remember if you create a 5+1 and decide to expand that tier later on, use another 5+1 group to avoid creating unbalanced performance in the tier.
Hussam_Sawaqed
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February 16th, 2015 01:00
Thank you so much.
i will be creating two pools:
first pool contains 7 FAST VP disks(R5) and 16 SAS disks(RAID10 (4+4))
second Pool contains only SAS and NL-SAS drives.
in VNX2 is it possible to choose (5+1) while configuring the storage tiers?
if i follow the best practices then Raid 5 with (4+1) and two disks as hot spare ? is that consider a waste of capacity ?
last one, the hot spare should be placed on the same Enclosure or it does not matter ?
Many Thanks,
Hussam_Sawaqed
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February 16th, 2015 03:00
thanks a million , so the best way to make the tier from those 7 fast VP drives is to place them on the first DAE in Bus 1 ( Bus 1 enclosure 0) the 7 disks will allocate 7 slots and 8 slots will be empty ( what do you prefer in such case to fill the rest of slots with SAS or NL-SAS) ????
BUS 1 ENC 0
0 FAST-VP
1 FAST-VP
2 FAST-VP
3 FAST-VP
4 FAST-VP
5 FAST-VP
6 FAST-VP
7 Empty
8 Empty
9 Empty
10 Empty
11 Empty
12 Empty
13 Empty
14 Empty
brettesinclair
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February 16th, 2015 15:00
That'll be fine, but fill the DAE up with other disks too.
When you have multiple pools, and small configs like this, I try and keep disks in the same pool on the same BUS.
Allen Ward
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February 17th, 2015 10:00
I would have to start with a question of "How did you end up with an array with that config?"
Someone must have put the config together to meet a specific need. Did you order from EMC or a Partner? Did you ask for a specific capacity or for specific drive counts. Who determined what the drive counts were going to be?
I guess what I'm struggling with as the starting question is how you end up with an array without knowing why it has the drives it does and what the intent was when it was ordered. Or did you inherit this drive from someone who left the company after ordering it?
Allen Ward
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February 17th, 2015 13:00
Thanks Brett. I missed the original post.
I agree that sometimes you have to deal with what you end up with... I just like to call it out in case there is a partner out there selling configs with no support to the end users. Or maybe it's and EMC Account team that needs a swift kick. Just asking probing questions in case either is true :-)
brettesinclair
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715 Posts
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February 17th, 2015 13:00
I agree Allen, and intimated my thoughts in Hussam's original post where he posted the inventory wanting a sample config.
Re: VNX 5600 distribute disk drive across the DPE and DAEs
In any case, I suppose he's ended up with this bom so has to do make the best of what he has.