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1 Rookie
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19 Posts
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1298
February 6th, 2015 05:00
how to configure FAST on cx4 (flare 4.30)
Hello.
I have a cx4-240 with latest flare 4.30 and the FAST suite enabled.
I've SATA disks and FC disks.
I want to create a storage pool with the tier enabled.
I already done that operation on a VNX storage, and I can select raid6 for SATA disks and raid5 for FC disks, and keep that mixed raid in Storage Pool.
On cx4-240 I can't found how to choose differents raid type for different disk tipology.
If I create a storage pool witch FC disks in raid5 I can only add SATA disks in raid5, and if I create a storage pool with SATA disks in raid6 I can only add FC disks in raid6, so I go out best paratic.
I found a lot of documents on performance strategy that explain when use the 2/3tier and all the best pratic on raid5/6 and some document that explain the existence of 'tier' tab in storage pool properties, but I have no found a User/Admin Guide how to create a storage pool with FAST well configured.
Someone can help me?
brettesinclair
2 Intern
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715 Posts
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February 6th, 2015 05:00
Clariion only supports FAST VP with a single RAID level per pool, not mixed like in VNX .
You cannot have different RAID levels on different tiers in a pool.
mrossini1
1 Rookie
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19 Posts
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February 6th, 2015 05:00
thankyou,
So do you suggests to create raid6 or raid5?
Another question...
Currently I've just 8 sata disks free
My idea is to create a storage pool with that disks, next move luns from already existant FC raidgroup, next destroy raidgroup and insert that disks in storage pool; now I expect that storage pool detect sata as "capacity" disks and FC as "performance" disks (or similar) and the tier move luns to fc disks when they are used.
Is this correct?
In a document I found a particular note that I did not understood:
https://support.emc.com/docu43303_FAST-for-FLARE-OE-Release-Notes-04.30.000.5.525.pdf?language=en_US
Data not moved to improve performance:
If a pool is expanded (additional physical drives are added),FAST will
not attempt to move data within a tier to improve performance.
However, FAST will use the new space for data relocation from other
(higher or lower) tiers.
so when I add the FC disks the pool will not use these for already existent luns?
thankyou
Matteo
DELL-Sheron G
Moderator
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228 Posts
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February 6th, 2015 07:00
Hey Matteo,
Hope this helps : http://www.emc.com/collateral/hardware/white-papers/h8234-fast-clariion-wp.pdf
Regards,
Sheron Godfred
brettesinclair
2 Intern
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715 Posts
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February 8th, 2015 00:00
You need to weigh up the advantages of RAID 5 or 6 for your circumstance.
Consider w/r performance, space used for parity, hot spares, rebuild times etc.
Your plan to create a pool with sata disks, migrate LUN's then add fc disks from the destroyed RG will work fine and you will have the performance and capacity tiers.
In regards to "Data not moved to improve performance".
This is the case only if you expand a tier(s) in the pool in the future, whereby FAST will not move the data intra-tier (rebalance).
If you create the pool from scratch with your FC and SATA disks, you can place new LUN's into the highest tier (fc), lowest tier (sata) or have FAST analyse and move the data slices up or down automatically (auto tier).
If you add more disks to a tier later on (fc as an example), the data already in the tier does not get re-balanced across the . new drives.