From: lspnet <lspnet@126.com>
To: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] help with understanding qcow2 file format
Date: Fri, 29 Jan 2016 14:40:15 +0000 (UTC) [thread overview]
Message-ID: <loom.20160129T150306-389@post.gmane.org> (raw)
In-Reply-To: 55F972A6.50906@redhat.com
hi，I have read 2015-qcow2-expanded.pdf and qcow2.txt，
so I understand how to convert the offset in the virtual disk to the
offset into the image file（qcow2).
but I wish to know how to convert the block using ext4 to the offset in
the virtual disk. Please help me.
the file block information is below:
cloud@cloud-pc:$ sudo debugfs /dev/vda1
debugfs: blocks /home/cloud/test
347008
cloud@cloud-pc:$ stat /home/cloud/test
File: /home/cloud/test
size:8 Blocks:8 IO Block:4096 regular file
Device: fd01h/64769d Inode:131601 Links:1
OS' file system information is below: (ubuntu 14.04, ext4)
cloud@cloud-pc:$ fdisk -l
Disk /dev/vda: 8589 MB, 8589934592 bytes
16 heads, 63 sectors/track, 16644 cylinders, total 16777216 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000005f4
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 12582911 6290432 83 Linux
/dev/vda2 12584958 16775167 2095105 5 Extended
/dev/vda5 12584960 16775167 2095104 82 Linux swap
/ Solaris
cloud@cloud-pc:$ dumpe2fs -h /dev/vad1
Filesystem volume name: <none>
Last mounted on: /
Filesystem UUID: bbcbbb0e-a335-46fe-b829-b4bf7bef513b
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Filesystem features: has_journal ext_attr resize_inode dir_index
filetype needs_recovery extent flex_bg sparse_super large_file
huge_file uninit_bg dir_nlink
extra_isize
Filesystem flags: signed_directory_hash
Default mount options: user_xattr acl
Filesystem state: clean
Errors behavior: Continue
Filesystem OS type: Linux
Inode count: 393216
Block count: 1572608
Reserved block count: 78630
Free blocks: 716304
Free inodes: 215296
First block: 0
Block size: 4096
Fragment size: 4096
Reserved GDT blocks: 383
Blocks per group: 32768
Fragments per group: 32768
Inodes per group: 8192
Inode blocks per group: 512
Flex block group size: 16
Filesystem created: Thu Jan 21 14:42:55 2016
Last mount time: Fri Jan 29 21:25:03 2016
Last write time: Fri Jan 29 21:25:03 2016
Mount count: 7
Maximum mount count: -1
Last checked: Thu Jan 21 14:42:55 2016
Check interval: 0 (<none>)
Lifetime writes: 4221 MB
Reserved blocks uid: 0 (user root)
Reserved blocks gid: 0 (group root)
First inode: 11
Inode size: 256
Required extra isize: 28
Desired extra isize: 28
Journal inode: 8
First orphan inode: 131699
Default directory hash: half_md4
Directory Hash Seed: 475ee556-9a7f-4c7b-93c3-21249906efea
Journal backup: inode blocks
Journal features: journal_incompat_revoke
Journal size: 128M
Journal length: 32768
Journal sequence: 0x00000dc8
Journal start: 18
cloud@cloud-pc:$ cat /etc/fstab
# /etc/fstab: static file system information.
# <file system> <mount point> <type><options><dump> <pass>
# / was on /dev/vda1 during installation
UUID=bbcbbb0e-a335-46fe-b829-b4bf7bef513b /
ext4 errors=remount-ro 0 1
# swap was on /dev/vda5 during installation
UUID=e2e3ec5c-dc4c-4f5d-a176-0f166b419785 none swap sw 0 0
prev parent reply other threads:[~2016-01-29 14:45 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-16 10:56 [Qemu-devel] help with understanding qcow2 file format Vasiliy Tolstov
2015-09-16 11:04 ` Laszlo Ersek
2015-09-16 11:15 ` Vasiliy Tolstov
2015-09-16 11:58 ` Markus Armbruster
2015-09-16 13:46 ` Eric Blake
2015-09-17 7:07 ` Vasiliy Tolstov
2015-09-17 14:38 ` Eric Blake
2016-01-29 14:40 ` lspnet [this message]
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