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.TH "SYSTEMD\&.IMAGE\-FILTER" "7" "" "systemd 258" "systemd.image-filter"
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.SH "NAME"
systemd.image-filter \- Disk Image Dissection Filter
.SH "DESCRIPTION"
.PP
In systemd, whenever a disk image (DDI) implementing the
\m[blue]\fBDiscoverable Partitions Specification\fR\m[]\&\s-2\u[1]\d\s+2
is activated, a filter may be specified controlling which partitions to consider for mounting\&. Such a disk image dissection filter is a string that contains per\-partition\-type patterns, separated by colons (":")\&. The individual rules consist of a partition identifier, an equal sign ("="), and a shell globbing pattern applied to the GPT label string of the partition\&. See
\fBglob\fR(7)
for details on shell globbing\&.
.PP
The partition identifiers currently defined are:
\fBroot\fR,
\fBusr\fR,
\fBhome\fR,
\fBsrv\fR,
\fBesp\fR,
\fBxbootldr\fR,
\fBswap\fR,
\fBroot\-verity\fR,
\fBroot\-verity\-sig\fR,
\fBusr\-verity\fR,
\fBusr\-verity\-sig\fR,
\fBtmp\fR,
\fBvar\fR\&. These identifiers match the relevant partition types in the Discoverable Partitions Specification, but are agnostic to CPU architectures\&.
.SH "USE"
.PP
Various systemd components that support operating with disk images support a
\fB\-\-image\-filter=\fR
command line option to specify the image filter to use\&. If no filter is specified all partitions in partition table are considered and no per\-label filtering is applied (except that partitions with the
"_empty"
label are always ignored)\&.
.PP
For the host root file system image itself
\fBsystemd-gpt-auto-generator\fR(8)
is responsible for processing the GPT partition table and making use of the included discoverable partitions\&. It accepts an image filter via the kernel command line option
\fBsystemd\&.image_filter=\fR\&.
.SH "EXAMPLES"
.PP
The following image filter string dictates that for the root file system partition only partitions shall be considered whose label begins with
"ParticleOS\-"\&. For the
/usr/
partition the precise label
"ParticleOS_47110815"
is required\&.
.sp
.if n \{\
.RS 4
.\}
.nf
root=ParticleOS\-*:usr=ParticleOS_47110815
.fi
.if n \{\
.RE
.\}
.SH "SEE ALSO"
.PP
\fBsystemd\fR(1), \fBsystemd-dissect\fR(1), \fBsystemd-gpt-auto-generator\fR(8), \fBsystemd.image-policy\fR(7)
.SH "NOTES"
.IP " 1." 4
Discoverable Partitions Specification
.RS 4
\%https://uapi-group.org/specifications/specs/discoverable_partitions_specification
.RE