46 lines
858 B
Markdown
46 lines
858 B
Markdown
---
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title: 'Btrfs Fix'
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date: 2025-07-06T13:12:10+08:00
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draft: true
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summary: some summary
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---
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```
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sudo btrfs scrub start /
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sudo btrfs scrub status /
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```
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```
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sudo dmesg | grep BTRFS | bat
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```
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确定块大小
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```
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sudo btrfs inspect-internal dump-super /dev/mapper/root1 | grep -i sector
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```
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定位到 2537392 扇区错误，在服务器上的是：
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```
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3420: 124352.. 124384: 2537365.. 2537397: 33: 43046457: shared
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```
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在备份中的是：
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```
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3321: 124352.. 124384: 5818956505..5818956537: 33: 5789786767:
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```
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在服务器上，我们取 logical 10393157632 和它前面一个扇区处的数据 10393153536：
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```
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sudo btrfs-map-logical -l 10393157632 -b 40960 /dev/mapper/root1
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```
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得到物理偏移后，把数据 dd 出来：
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```
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sudo dd if=/dev/mapper/root1 bs=4096 skip=$((10393157632/4096)) count=1 of=/dev/shm/b1
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```
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