Rohail2004
Enthusiast
Enthusiast

vmdk copy

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I have a 10GB backbone, but whenever i copy a VM through CIFS it is always slow, but any other files except VMDKs copy much faster, so my question is why copying VMDK files windows to windows always slow?

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RParker
Immortal
Immortal

Rohail2004 wrote:

I have a 10GB backbone, but whenever i copy a VM through CIFS it is always slow, but any other files except VMDKs copy much faster, so my question is why copying VMDK files windows to windows always slow?

I don't care how much network bandwidth you have, networking is NEVER the limitation.  Disks are the problem, file system, IOPS, spindle speed.. RAID configuration, CACHE.. all factors.

It's really hard to say which or combination is the problem.. CIFS also is another complex layer.. maybe your CIFS server is not efficient...

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RParker
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Immortal

Rohail2004 wrote:

I have a 10GB backbone, but whenever i copy a VM through CIFS it is always slow, but any other files except VMDKs copy much faster, so my question is why copying VMDK files windows to windows always slow?

I don't care how much network bandwidth you have, networking is NEVER the limitation.  Disks are the problem, file system, IOPS, spindle speed.. RAID configuration, CACHE.. all factors.

It's really hard to say which or combination is the problem.. CIFS also is another complex layer.. maybe your CIFS server is not efficient...

View solution in original post

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bemymonkey
Contributor
Contributor

I'm actually having a similar problem - have a VM on my laptop, and when copying it off via network, as soon as it hits one of the .vmdk files, the transfer speed drops to a few 100KB/s (from 11MB/s).

The VM works just fine on the laptop, and the hard drive the VM is on works just fine too.

Are .vmdk files difficult to copy because of their data structure or something?         

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J1mbo
Virtuoso
Virtuoso

Are these copies being performed by download/upload function of the datastore browser?  As, those functions are actively limited to about 10MB/s.

You can copy full-speed by mounting the target as an NFS datastore.

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bemymonkey
Contributor
Contributor

I don't know about Rohail, but I meant just copying via Windows Explorer via a regular Windows 7 network share.        

-edit- Just realized that in this subforum, that's probably not very common :smileygrin:

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