kopia lustrzana https://github.com/cyoung/stratux
75 wiersze
1.7 KiB
Bash
Executable File
75 wiersze
1.7 KiB
Bash
Executable File
#!/bin/sh
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# Part of spindle http://asbradbury.org/projects/spindle
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#
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# See LICENSE file for copyright and license details
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# TODO: this script is very rough and ready. Currently shrinks ext4 image to
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# minimum size. Should really be refactored and merged with grow_image
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set -x
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if [ $(id -u) -ne 0 ]; then
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printf "Script must be run as root\n"
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exit 1
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fi
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if [ ! "$1" ]; then
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printf "Usage: ./shrink_image IMAGEFILE\n"
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exit 1
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fi
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IMAGEFILE="$1"
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# Partition resizing code same as in http://github.com/asb/raspi-config
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PART_START=$(parted "$IMAGEFILE" -ms unit s p | grep "^2" | cut -f 2 -d:)
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if [ ! "$PART_START" ]; then
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printf "Failed to extract root partition offset\n"
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fi
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# Just use losetup to create a loopback device. fdisk will operate on files,
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# but it complains about the number of cylinders not being set
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LOOP_DEV=$(losetup -f)
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# We know the offset anyway so let's just use losetup directly rather than
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# bothering with kpartx
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PART_START_BYTES=$((${PART_START%s}*512))
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losetup --offset "$PART_START_BYTES" -v $LOOP_DEV "$IMAGEFILE"
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# Sanity check
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file -s $LOOP_DEV
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# Run resize2fs
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e2fsck -f $LOOP_DEV
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resize2fs -M $LOOP_DEV
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EXT4_BLCKCNT=$(sudo tune2fs -l /dev/loop0 | grep "^Block count" | cut -d ":" -f 2 | tr -d ' ')
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EXT4_BLKSIZE=$(sudo tune2fs -l /dev/loop0 | grep "^Block size" | cut -d ":" -f 2 | tr -d ' ')
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EXT4_FS_BYTES=$(($EXT4_BLCKCNT * $EXT4_BLKSIZE))
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# Unmount it all
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losetup -d $LOOP_DEV
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NEW_IMG_BYTES=$(($EXT4_FS_BYTES + $PART_START_BYTES + 4194304))
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# Shrink the image file
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dd if=/dev/null of="$IMAGEFILE" bs=$NEW_IMG_BYTES seek=1
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losetup -v $LOOP_DEV "$IMAGEFILE"
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fdisk -cu $LOOP_DEV <<EOF
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p
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d
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2
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n
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p
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2
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$PART_START
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p
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w
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EOF
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losetup -d $LOOP_DEV
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printf "Success! (hopefully)\n"
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