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[[!meta title="zero store: empty block device"]]

A *zero* store is what `/dev/zero` is (always reads zeros), the setting on
`/dev/zero` gives no name (i.e. size) and the default size is the maximum
possible.  The only meaning of the size of a *zero* is what `st_size` will
report and what offsets it will let you try to read or write from--there is
never any data associated with a *zero* store.  (The code for this is in
`libstore/zero.c`.)