RBD 镜像实际大小

获取 rbd 镜像使用的实际大小

rbd diff $POOL/$IMAGE | awk '{ SUM += $2 } END { print SUM/1024/1024 " MB" }'

例如

$rbd info myrbd
rbd image 'myrbd':
    size 2048 MB in 512 objects
    order 22 (4096 KB objects)
    block_name_prefix: rb.0.2c6a.238e1f29
    format: 1

$ rbd diff myrbd | awk '{ SUM += $2 } END { print SUM/1024/1024 " MB" }'
14.2812 MB

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