d6f7e3da0d
Previously btrfs-image would set a METADUMP flag and would make one big system chunk to cover the entire file system in the super in order to get around the unpleasant business of having to adjust the chunk tree. This meant that you could use the progs stuff on a restored file system, which is great for testing btrfsck and other such things. But we want to be able to run the tree log replay on a file system that is not able to run the tree log replay. So in order to do this we need to fixup the super's chunk array and the chunk tree itself. This is pretty easy since we restore using the logical offsets of the metadata, so we just have to set the chunk items to have 1 stripe and have the stripes point at the primary device and then use the logical offset of the chunk as the physical offset. With this patch I can restore a file system image that had a tree log and mount the file system and have the log be replayed successfully. This patch also gives you the -o option in case you want the old restore way, in the case where we want to make sure the system chunks as they were given to us are correct. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
39 lines
1.2 KiB
Groff
39 lines
1.2 KiB
Groff
.TH BTRFS-IMAGE 8
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.SH NAME
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btrfs-image \- create/restore an image of the filesystem
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.SH SYNOPSIS
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.B btrfs-image
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[options] \fIsource\fP \fItarget\fP
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.SH DESCRIPTION
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.B btrfs-image
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is used to create an image of a btrfs filesystem. All data will be zeroed,
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but metadata and the like is preserved.
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.I source
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is the special file corresponding to the device containing a btrfs filesystem.
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(e.g \fI/dev/sdXX\fP).
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.I target
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is the image file that btrfs-image creates. When used with \fB-r\fP option,
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\fBbtrfs-image\fP restores the image file from source into target.
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.SH OPTIONS
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.TP
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\fB\-r\fP
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restore metadump image.
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.TP
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\fB\-c\fR \fIvalue\fP
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compression level (0 ~ 9).
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.TP
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\fB\-t\fR \fIvalue\fP
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number of threads (1 ~ 32) to be used to process the image dump or restore.
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.TP
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\fB\-o\fP
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use the old restore method, this does not fixup the chunk tree so the restored
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file system will not be able to be mounted.
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.SH AVAILABILITY
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.B btrfs-image
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is part of btrfs-progs. Btrfs is currently under heavy development,
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and not suitable for any uses other than benchmarking and review.
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Please refer to the btrfs wiki
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http://btrfs.wiki.kernel.org for further details.
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.SH SEE ALSO
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.BR btrfsck (8), mkfs.btrfs (8)
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