rsync - Mar 2009 - Is it possible to make rsync VMware split .vmdk's aware?

Hi,

 

I am using rsync for my customers to have disaster recovery off-site
with files from a VMware Server (under Linux). All works very well, but
when I defragment the VM's (once a week) or Exchange defragments it's
datastore the disk layout changes offcourse and sometimes a lot.

 

What do I do:

-          I am making a local copy with vmware-vdiskmanager to an USB
disk in the split "thin-disk" format of the vmdk's

-          Then I start rsync to our datacenter to replicate the split
"thin-disk" vmdk's

 

What happens:

Sometimes, because of the defragment within the VM or Exchange, the disk
layout changes so much that a split .vmdk file that was very little and
now becomes filled with 2Gb data. As a result rsync has to transfer 2Gb
of data for that .vmdk which takes a lot of time. In my opnion that's
not nessesary because the data is probably available in another split
.vmdk because it was moved across the virtual disk.

 

My question:

Is it possible to make an option in Rsync which reads out the vmdk
config file for the split disks so it can search for known data across
all the split .vmdk files within one virtual disk? If this is possible
this will improve the rsync process in a major way!

 

The .vmdk config file looks like this:

 

Contents of "PVSBS2K3-1.vmdk":

# Disk DescriptorFile

version=1

CID=ee057ac0

parentCID=ffffffff

createType="twoGbMaxExtentSparse"

 

# Extent description

RW 4192256 SPARSE "PVSBS2K3-1-s001.vmdk"

RW 4192256 SPARSE "PVSBS2K3-1-s002.vmdk"

RW 4192256 SPARSE "PVSBS2K3-1-s003.vmdk"

RW 4192256 SPARSE "PVSBS2K3-1-s004.vmdk"

RW 4192256 SPARSE "PVSBS2K3-1-s005.vmdk"

RW 4192256 SPARSE "PVSBS2K3-1-s006.vmdk"

RW 4192256 SPARSE "PVSBS2K3-1-s007.vmdk"

RW 4192256 SPARSE "PVSBS2K3-1-s008.vmdk"

RW 4192256 SPARSE "PVSBS2K3-1-s009.vmdk"

RW 4192256 SPARSE "PVSBS2K3-1-s010.vmdk"

RW 4192256 SPARSE "PVSBS2K3-1-s011.vmdk"

RW 4192256 SPARSE "PVSBS2K3-1-s012.vmdk"

RW 2147202 SPARSE "PVSBS2K3-1-s013.vmdk"

 

# The Disk Data Base 

#DDB

 

ddb.geometry.biosHeads = "255"

ddb.geometry.biosSectors = "63"

ddb.geometry.biosCylinders = "3265"

ddb.uuid = "60 00 C2 92 f3 f3 f2 72-66 dc e5 10 bd 92 16 44"

ddb.virtualHWVersion = "4"

ddb.toolsVersion = "6535"

ddb.geometry.cylinders = "3265"

ddb.geometry.heads = "255"

ddb.geometry.sectors = "63"

ddb.adapterType = "lsilogic"

 

 

I am looking forward to your answer,

 

Thanks in advance,

 

Bas Bahlmann

The Netherlands

 

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On Wed, 2009-03-18 at 09:02 +0100, Bas Bahlmann || Steady IT
Systeembeheer wrote:
> -         I am making a local copy with vmware-vdiskmanager to an USB
> disk in the split ?thin-disk? format of the vmdk?s
> 
> -         Then I start rsync to our datacenter to replicate the split
> ?thin-disk? vmdk?s
> Sometimes, because of the defragment within the VM or Exchange, the
> disk layout changes so much that a split .vmdk file that was very
> little and now becomes filled with 2Gb data. As a result rsync has to
> transfer 2Gb of data for that .vmdk which takes a lot of time. In my
> opnion that?s not nessesary because the data is probably available in
> another split .vmdk because it was moved across the virtual disk.
> Is it possible to make an option in Rsync which reads out the vmdk
> config file for the split disks so it can search for known data across
> all the split .vmdk files within one virtual disk?
Specific support for VMware split images would be way too
special-purpose to justify putting it in the main version of rsync.  A
more general option to make each file transfer use multiple basis files
(or even all the existing destination files) may be reasonable.  You
could join this enhancement request, which I might then reopen:

https://bugzilla.samba.org/show_bug.cgi?id=5954

But in this scenario, why are you using a split image?  Does it have
some advantage over a monolithic image (with which rsync would Just
Work)?

-- 
Matt