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FC R5 and FC R1 in FAST VP
The drives are same rpm on both disk groups/pools, r5 and r1. Is the code smart enough to move write intensive load to r1 drives? Or someone point me to a documentation how FAST promotes and demotes workload based drive type, raid type, etc.
TIA.
Quincy561
1.3K Posts
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March 12th, 2014 10:00
If you have FC drives of both RAID5 and RAID1 in the same FAST policy, they will be treated the same. It is not recommended. Using RAID1 for the middle tier is highly recommended.
M_Salem
213 Posts
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March 12th, 2014 10:00
This doc should be a good start to understand FAST VP
https://support.emc.com/docu31003_FAST_VP_for_Symmetrix_VMAX_Theory_and_Best_Practices_for_Planning_and_Performance.pdf
cincystorage
467 Posts
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March 12th, 2014 10:00
FAST Works based on drive technology not protection scheme. So SSD is SSD, FC is FC, and SATA is SATA. You eally don't want to mix raid types in a FAST pool.
Shanmugas
22 Posts
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March 12th, 2014 10:00
"3- FAST VP does not take Protection into considerations." - That answers my doubt, but I wish that is changed in the future though.
Shanmugas
22 Posts
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March 12th, 2014 10:00
Thx. Do you have any write up or doc which explain the details of how FAST works?
P.S - I lived in Quincy, MA for couple years.
M_Salem
213 Posts
1
March 12th, 2014 10:00
Shanmugas,
The code will not return any error if you try to add 2 FC tier created from 2 FC pools one with RAID1 TDATs and another with RAID5 TDATs. Simply the code will accept this.
BUT.....
This will lead to UNEXPECTED FAST VP Behavior..... SO DO NOT DO IT.
The Recommendations:
1- Make sure you have one tier technology per policy
2- If you have such situations that you have same technology and protection drives but different pools then you can add these pools to a single tier representing the same technology for instance 2 pools one with FC 15K 450GB and configured as RAID1 and another pool configured with15K 600GB drives as RAID 1 can be both added to same tier.
3- FAST VP does not take Protection into considerations. This is another thing that you should consider. It depends on your Workload, Applications, Capacity, Cost....
4- The only solution i can see for your situation is to use 2 different tiers one for each pool in 2 different policies.
Hope it helps...
Mohammed Salem
M_Salem
213 Posts
0
March 12th, 2014 11:00
Adding to what Mark said, VLUN migration can be used for migration from protection to another.However, it does not work for your case as both pools are created out of Disks in the same disk group as you mentioned.
Mohammed Salem