Basic Bcache Operations

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make-bcache  -B /dev/sdx1 -C /dev/sdx2

-B: specifies a backend drive (data drive).

-C: specifies a cache device (for accelerating the data drive).

Example: Create backend drive sdb and cache device sdc.

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make-bcache  -B /dev/sdb -C /dev/sdc

1. View the cset-uuid of a cache drive.

   1	bcache-super-show /dev/sd*

   Example: View the cache device sdc.

   1	bcache-super-show /dev/sdc

   

2. Clear the cache.

   1	echo $cset-uuid > /sys/block/bcache<n>/bcache/detach

   Example: Delete the cache drive whose cset-uuid is 5f50eddf-69d8-45e3-9b67-7386ffdaceb7.

   1	echo 5f50eddf-69d8-45e3-9b67-7386ffdaceb7 > /sys/block/bcache0/bcache/detach

   Then sdc is detached from bcache0.

   

   To re-attach the cache, run the following command:

   1	echo cset-uuid > /sys/block/bcache<n>/bcache/attach

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echo 1  > /sys/fs/bcache/<cset-uuid>/unregister

Example: Deregister the cache drive whose cset-uuid is 5f50eddf-69d8-45e3-9b67-7386ffdaceb7.

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echo 1  > /sys/fs/bcache/5f50eddf-69d8-45e3-9b67-7386ffdaceb7/unregister

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echo 1  > /sys/fs/bcache/<cset-uuid>/stop

Example: Disable the cache drive whose cset-uuid is 5f50eddf-69d8-45e3-9b67-7386ffdaceb7.

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echo 1  > /sys/fs/bcache/5f50eddf-69d8-45e3-9b67-7386ffdaceb7/stop

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echo 1 > /sys/block/bcache<n>/bcache/stop

Example: Disable the backend device whose n is 0.

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echo 1 > /sys/block/bcache0/bcache/stop

Then both sdb and sdc are detached from bcache0.