NAME¶

daxio - Perform I/O on Device DAX devices or zero a Device DAX device

SYNOPSIS¶

$ daxio [<options>]

DESCRIPTION¶

The daxio utility performs I/O on Device DAX devices or zero a Device DAX device. Since the standard I/O APIs (read/write) cannot be used with Device DAX, data transfer is performed on a memory-mapped device. The daxio may be used to dump Device DAX data to a file, restore data from a backup copy, move/copy data to another device or to erase data from a device.

There must be at least one Device DAX device involved either as the input or output. If input or output is not specified, it will default to stdin or stdout respectively.

No length specified will default to input file/device length or to the output file/device length, if input is a special char file or stdin.

For a Device DAX device, daxio will attempt to clear bad blocks within the range of writes before performing the I/O (it can be turned off using the `–clear-bad-blocks=no' option).

OPTIONS¶

-i, --input Input device or file to read from.

-o, --output Output device or file to write to.

-z, --zero Zero the output device for len size, or the entire device if no length was provided. The output device must be a Device DAX device.

-b, --clear-bad-blocks=<yes|no> Clear bad blocks within the range of writes before performing the I/O (default: yes).

-l, --len The length in bytes to perform the I/O. To make passing in size easier for kibi, mebi, gibi, and tebi bytes, len may include unit suffix. The len format must be compliant with the format specified in IEC 80000-13, IEEE 1541 or the Metric Interchange Format. These standards accept SI units with obligatory B - kB, MB, GB, ... (multiplier by 1000) suffixes, and IEC units with optional “iB” - KiB, MiB, GiB, ..., K, M, G, ... (multiplier by 1024) suffixes.

-s, --seek The number of bytes to skip over on the output before performing a write. The same suffixes are accepted as for len.

-k, --skip The number of bytes to skip over on the input before performing a read. The same suffixes are accepted as for len.

-V, --version

Prints the version of daxio.

-h, --help

Prints synopsis and list of options.

EXAMPLE¶

# daxio --zero /dev/dax1.0
# daxio --input=/dev/dax1.0 --output=/home/myfile --len=2M --seek=4096
# cat /dev/zero | daxio --output=/dev/dax1.0
# daxio --input=/dev/zero --output=/dev/dax1.0 --skip=4096

SEE ALSO¶

daxctl(1), ndctl(1) and <https://pmem.io>