NAME¶

vdocalculatesize - Calculate VDO space and memory usage

SYNOPSIS¶

vdocalculatesize [options...]

DESCRIPTION¶

vdocalculatesize calculate VDO space and memory usage

OPTIONS¶

--help

Print help message and exit.

--block-map-cache-size=blocks

Size of the block map cache, in 4K blocks

--logical-size=MB

VDO logical size

--physical-size=MB

VDO physical size

--slab-bits=bits

Set the free space allocator's slab size to 2^bits 4 KB blocks. bits must be a value between 13 and 23 (inclusive), corresponding to a slab size between 32 MB and 32 GB. The default value is 19 which results in a slab size of 2 GB. This allocator manages the space VDO uses to store user data.

The maximum number of slabs in the system is 8192, so this value determines the maximum physical size of a VDO volume. One slab is the minimum amount by which a VDO volume can be grown. Smaller slabs also increase the potential for parallelism if the device has multiple physical threads. Therefore, this value should be set as small as possible, given the eventual maximal size of the volume.

--slab-size=MB

set slab-size directly instead of using --slab-bits. This option is mutually exclusive with --slab-bits.

--index-memory-size=GB

Specify the amount of memory, in gigabytes, to devote to the index. Accepted options are .25, .5, .75, and all positive integers.

--sparse-index

Specify whether or not to use a sparse index.

EXAMPLE¶

vdoCalculateSize --physical-size 600G --slab-bits 22 --logical-size 2T --index-memory-size 1 --block-map-cache-size 32768

SEE ALSO¶

vdo(8).