Difference between revisions of "Fs-images"

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= Disk images =

== How to backup a whole HD ==

The byte size ''bs'' is useful to do a fast copy, specially then output location is remotly on a network

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dd if=/dev/sda of=/path/to/store/disk.img bs=4096

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To mount a partition from here, you have to consider that you have to ignore partition table.

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mount -o loop,offset=32256 /path/to/store/disk.img /mnt/mydisk

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== How to backup only one partition from a HD ==

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dd if=/dev/sda1 of=/path/to/store/disk.img bs=4096

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== How to convert a raw image from HD in a VMWare HD image ==

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qemu-img convert -f raw /path/to/image/XPSP2.img -O vmdk /path/to/image/XPSP2.vmdk

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== How to create a filesystem for CentOS 5 an older distros ==

One of the issues is grub is unable to read the filesystem, and must of the time is because the recent distros uses 256-byte node size.

In order to fix it, specially on VMs, do:

# Create the virtual drive as usual

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# qemu-img create -f raw disk.img 20G

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# boot using a knoppix image as cdrom

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# qemu-system-x86_64 -m1024 -hda disk.img -cdrom knoppix.iso -boot d

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# On knoppix prompt, type ''knoppix 3'', in order to boot in init level 3

# From the shell, start cfdisk and add only one linux partition.

# Create the filesyste in the created partition with 128-byte node size

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# mkfs.ext3 -I 128 /dev/sda1

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# Turn off the virtual machine

# Now, you can mount the drive as a real physical disk with

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# mkdir disk

# mount -o loop,offset=32256 disk.img disk/

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