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Copyright@2004~2014 Qsan Technology, Inc. All Rights Reserved.
Qsan Document – User Manual
The following steps describe details about a host read with a cache miss:
1.
A host requests a read data.
2.
Read data from the HDD.
3.
Return requested data to the host.
4.
Populate the cache to SSD.
Read Data with Cache Hit
The following figure shows the steps of the controller which handles a host read request
when the data is in the SSD cache.
HDD
SSD
Memory Cache
Data
2. Read from HDD
4. Populate Cache
1. Request Read
3. Return Data
SSD
HDD
Memory Cache
Data
4. Read from HDD
(SSD Failure Case)
2. Read from SSD
1. Read
3. Return Data
