R1-Elastic Cache

> R1-Elastic Cache

> R1-elastic cache (R1-EC), a new RAID protection from LSI for the Nytro Flash modules.The R1-elastic cache feature of Nytro MegaRAID accelerates the I/O throughput and enhances the endurance of the Nytro Cache drive. R1-elastic cache is another protection level along with RAID 1 and RAID 0. In elastic cache, host-writes are mirrored and host-reads are not mirrored.

> When the data get mirrored on both drives, the logical block address would be different from one another as opposed to RAID 1. That is, the second drive is not a replica of the first drive in an array as shown in the following figure.

> Figure 1. R1-Elastic Cache (EC) Block

> The size of R1-elastic cache (EC) would be larger than RAID 1 Nytro Cache drive and lesser than RAID 0 Nytro Cache drive. This is achieved by mirroring only the host-written data. Because of this, the usable capacity of the Nytro Cache drive depends on the I/O from the host.

DB15-000988-08-December 2013
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