Size Can Matter: Would You Prefer the Hard Drive or the Ramdisk this Evening? Part 3
The past couple of weeks we ran the numbers on metadata performance for ramdisks and hard drive-based journals for ext4. Now let’s compare/contrast the two journal devices and see what trends emerge.
Tuesday, January 26th, 2010
In part 1 of this series we looked at the metadata performance when your journal was on a separate disk. Part 2 explored the ramdisk option. Now comes the favorite part of every high school English class: Compare and contrast. These tests are not intended as “benchmarks” per se. They are intended more as experiments or explorations to determine how we can influence storage performance by changing options in the file system. This means we are not looking for a “winner” in the comparison. Rather, we are looking for differences or the lack of differences in metadata performance as a function of journal size and journal device to perhaps tell us something about how we can improve performance.
Testing Review
Recall that four journal sizes were tested to understand the impact of journal size on metadata performance. The four journal sizes are:
