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FAST-VP and writes allocation
hi
new writes will allocate new extents in the original Thin pool where thin dev is bounded
what about over write an extent that is already promoted to different thin pool/tier
Quincy561
1.3K Posts
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December 7th, 2014 07:00
Prior to the "allocation by policy" feature, you would be correct. When this feature is enabled, the new allocations can come from the bound pool, or any other pool in the FAST policy if FAST thinks they would be a better choice based on the workload.
And for tracks already allocated, overwrites will not move the tracks.
M_Salem
213 Posts
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December 7th, 2014 03:00
Hi Mosa3lyan,
Welcome to EMC Community.
For your first statement this may not be the case if VP allocation by FAST policy is enabled.
For your question about new writes, I need more clarifications to give you the right answer..
HTH
-Mohammed Salem
Mosa3lyan
265 Posts
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December 7th, 2014 05:00
thx Salem
so for FAST-VP
for a new write that will allocate new extents , where these new extents will be allocated (on original Thin Pool where the tdev is bounded ) or where ?
and for
overwriting an extents that already allocated and promoted to different thin pool than the thin pool where the tdevv where bounded ,?
Mosa3lyan
265 Posts
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December 7th, 2014 07:00
thanks John
Mosa3lyan
265 Posts
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December 7th, 2014 07:00
so FAST-VP will improve read and write not only read
thx again
Quincy561
1.3K Posts
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December 7th, 2014 09:00
Read miss gives the highest scores to read miss for FAST VP promotion, but back-end write activity will also increase scores for promotion with FAST VP.