Flash is een game changing technology, althans dat is wat de markt u graag wil doen geloven. Immers, voorspelbare consistente performance en IO efficiency worden hierdoor mogelijk gemaakt. Maar…
- Microsecondes maken het verschil maar de spelregels veranderen niet.
- Not all Flash was created equal
- Disk is niet dood, al willen sommige leveranciers dat u doen geloven
Bekijk deze presentatie om een nuchtere kijk op Flash te krijgen en uit te vinden wat de echte impact is op uw datacenter infrastructuur.
12. Data ONTAP and Flash
Optimized Writes Illustrated - I
Storage
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CPU
Memory
NVRAM
Slower
<1ms >8ms
Writes
Ack.
• Incoming writes are processed in memory, protected in NVRAM and
acknowledged resulting in fast write response time.
• Writes to the SSDs are not in the critical latency path
1
3
2
13. Data ONTAP and Flash
Optimized Writes Illustrated - II
Storage
6
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CPU
Memory
Slower
~1ms
NVRAM
A B
C D Used A B C D
Free
4
5
Writes are coalesced together in memory and destaged to SSD
Blocks are always written to new locations
Temporal locality to write metadata alongside user data in a way designed to minimize the
number of disk operations required to commit data to SSDs.
Write striping results in maximizing performance and reducing uneven SSD wear
4
5
6
14. Data ONTAP and Flash
Flash Made Simple
3 Year – Standard
2 Year – Extended
Must meet endurance and performance expectations
Write endurance (DWPD) is more critical than NAND type
Warrantied for 5 years
Warrantied up to 5 years (regardless of # of writes)
Currently use mixed use drives (10 DWPD)
Life expectance well beyond 5 years
Guaranteed by NetApp
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