Table 3 Block device parameters in use for performance evaluation
From: Host managed contention avoidance storage solutions for Big Data
Block device | Default parameters |
|---|---|
HDD | Maximum “request” structure size = 512 kB |
Request queue size = 256 BIO structures (128 reads, 128 writes) | |
Max. size of each block I/O (BIO) structure = 128 × 4K pages | |
1 page (bio vec) = 8 × 512-byte disk sectors (block) | |
Access granularity (disk block sector size) = 512 bytes | |
Specification based exactly as our 250 GB Hadoop cluster HDD | |
SSD | Block size = 256 pages; page size = 4 kB = access granularity |
Access time: read = 0.025 ms; write = 0.5 ms | |
Specification based on SLC Flash SSD [9] |