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Version: 1.3

Change the SSD cache flush ratio

This article describes the following topics​

  • Changing the SSD cache ratio to meet your need

Connect to a Controller​

ssh [email protected]

Profile - default​

  • will begin flushing dirty objects when 20% of the pool is dirty and begin evicting clean objects when we reach 60% of the target size.
ceph osd pool set cachepool cache_target_full_ratio 0.6
ceph osd pool set cachepool cache_target_dirty_high_ratio 0.4
ceph osd pool set cachepool cache_target_dirty_ratio 0.2

Profile - slow​

  • will begin flushing dirty objects when 40% of the pool is dirty and begin evicting clean objects when we reach 80% of the target size.
ceph osd pool set cachepool cache_target_full_ratio 0.8
ceph osd pool set cachepool cache_target_dirty_high_ratio 0.6
ceph osd pool set cachepool cache_target_dirty_ratio 0.4

Profile - fast​

  • will begin flushing dirty objects when 10% of the pool is dirty and begin evicting clean objects when we reach 30% of the target size.
ceph osd pool set cachepool cache_target_full_ratio 0.3
ceph osd pool set cachepool cache_target_dirty_high_ratio 0.2
ceph osd pool set cachepool cache_target_dirty_ratio 0.1
Last updated on by Roy Tan