On Thu, Nov 12, 2009 at 12:32 PM, Mr. Teo En Ming (Zhang Enming) < [email protected]> wrote:
> > > On Thu, Nov 12, 2009 at 10:55 AM, Mr. Teo En Ming (Zhang Enming) < > [email protected]> wrote: > >> >> >> On Thu, Nov 12, 2009 at 10:45 AM, Bryn M. Reeves <[email protected]> wrote: >> >>> On Thu, 2009-11-12 at 09:23 +0000, Mr. Teo En Ming (Zhang Enming) wrote: >>> > Hi All, >>> > >>> > I have several Xen virtual machines within logical volumes using LVM2. >>> > I did not use disk images for performance reasons. >>> > >>> > Conventionally, if I want to clone my virtual machines, I have to dd >>> > the LV to an image file. But this consumes a lot of time and harddisk >>> > space. >>> > >>> > So, instead of doing that, I want to use losetup and kpartx with my >>> > logical volumes, which contain operating systems of virtual machines. >>> > >>> > I can backup the filesystems of a virtual machine in this way: >>> > >>> > # losetup /dev/loop1 /dev/virtualmachines/windows7-x64 >>> >>> What's the point of adding a loopback device on top of the LV? Running >>> kpartx on the LV itself will work just fine and this just adds an >>> unnecessary layer of overhead and complexity unless I am missing >>> something. >>> >>> > dd if=/dev/hda of=mbr.hda bs=512 count=1 >>> > >>> > Because /dev/hda resides in a logical volume. The logical volume is a >>> > virtual harddisk for my virtual machine. >>> >>> Assuming that the LV given above is a whole-disk image containing a DOS >>> MBR partition table: >>> >>> dd if=/dev/virtualmachines/windows7-x64 of=/tmp.mbr.img bs=512 count=1 >>> >>> You could also do the same with the loopN device that you set up >>> earlier, although I still don't see the need for that step. >>> >>> > 1) re-create the physical volume (PV) >>> > >>> > 2) re-create the volume group >>> > >>> > 3) assign the PV to the volume group >>> > >>> > 4) restore the LVM metadata, i.e. the configuration files for all the >>> > logical volumes >>> > >>> > 5) restore the MBR of my domU >>> > >>> > 6) restore the filesystems of my domU >>> >>> Should work fine, just be sure to test each step so that you are >>> confident and comfortable with it before you find yourself needing to do >>> this in anger. >>> >>> Regards, >>> Bryn. >>> >>> >>> -- >>> fedora-list mailing list >>> [email protected] >>> To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list >>> Guidelines: >>> http://fedoraproject.org/wiki/Communicate/MailingListGuidelines >>> >> >> Hi Bryn, >> >> I have just tried an experiment without the losetup step. I have verified >> that it works using kpartx only. >> >> r...@sysresccd /root % kpartx -av /dev/virtualmachines/winxphome32 >> add map virtualmachines-winxphome32p1 (253:22): 0 104840127 linear >> /dev/virtualmachines/winxphome32 63 >> r...@sysresccd /root % cd /dev/mapper >> r...@sysresccd /dev/mapper % ls *winxphome32* >> virtualmachines-winxphome32 virtualmachines-winxphome32p1 >> r...@sysresccd /dev/mapper % ls -al *winxphome32* >> brw-rw---- 1 root disk 253, 0 2009-11-12 15:49 >> virtualmachines-winxphome32 >> brw-rw---- 1 root disk 253, 22 2009-11-12 18:47 >> virtualmachines-winxphome32p1 >> r...@sysresccd /dev/mapper % ls -al *winxphome32* >> brw-rw---- 1 root disk 253, 0 2009-11-12 15:49 >> virtualmachines-winxphome32 >> brw-rw---- 1 root disk 253, 22 2009-11-12 18:47 >> virtualmachines-winxphome32p1 >> r...@sysresccd /dev/mapper % fdisk -l virtualmachines-winxphome32 >> >> Disk virtualmachines-winxphome32: 53.7 GB, 53687091200 bytes >> 255 heads, 63 sectors/track, 6527 cylinders >> >> Units = cylinders of 16065 * 512 = 8225280 bytes >> Disk identifier: 0x2b362b35 >> >> >> Device Boot Start End Blocks >> Id System >> virtualmachines-winxphome32p1 * 1 6526 52420063+ >> 7 HPFS/NTFS >> >> Without the losetup and the corresponding overhead, it will speed up >> cloning of my virtual machines within LVs. >> >> >> >> -- >> Mr. Teo En Ming (Zhang Enming) Dip(Mechatronics) BEng(Hons)(Mechanical >> Engineering) >> Alma Maters: >> (1) Singapore Polytechnic >> (2) National University of Singapore >> My Primary Blog: http://teo-en-ming-aka-zhang-enming.blogspot.com >> My Secondary Blog: http://enmingteo.wordpress.com >> My Youtube videos: http://www.youtube.com/user/enmingteo >> Email: [email protected] >> Mobile Phone (Starhub Prepaid): +65-8369-2618 >> Street: Bedok Reservoir Road >> Country: Singapore >> > > Hi All, > > I have performed a backup of my F11 Dom0's PV (60 GB) of 3 logical volumes > using fsarchiver with the maximum possible LZMA compression. The operation > took 4 hours with 2 compression threads. The resulting backup archive size > is 8.1 GB for a PV of 60 GB. > > My hardware specs: > > Intel Pentium Dual Core E6300 2.8 GHz > Intel Desktop Board DQ45CB > 6 GB DDR2-800 memory > > > -- > Mr. Teo En Ming (Zhang Enming) Dip(Mechatronics) BEng(Hons)(Mechanical > Engineering) > Alma Maters: > (1) Singapore Polytechnic > (2) National University of Singapore > My Primary Blog: http://teo-en-ming-aka-zhang-enming.blogspot.com > My Secondary Blog: http://enmingteo.wordpress.com > My Youtube videos: http://www.youtube.com/user/enmingteo > Email: [email protected] > Mobile Phone (Starhub Prepaid): +65-8369-2618 > Street: Bedok Reservoir Road > Country: Singapore > The fsarchiver command I have used is: fsarchiver savefs -v -z 9 -j 2 /mnt/hitachi/test/test.fsa /dev/vg_fedora11_host/lv_home /dev/vg_fedora11_host/lv_root /dev/vg_fedora11_host/lv_var -- Mr. Teo En Ming (Zhang Enming) Dip(Mechatronics) BEng(Hons)(Mechanical Engineering) Alma Maters: (1) Singapore Polytechnic (2) National University of Singapore My Primary Blog: http://teo-en-ming-aka-zhang-enming.blogspot.com My Secondary Blog: http://enmingteo.wordpress.com My Youtube videos: http://www.youtube.com/user/enmingteo Email: [email protected] Mobile Phone (Starhub Prepaid): +65-8369-2618 Street: Bedok Reservoir Road Country: Singapore
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