How are you mapping the latency? On the filer stats show -i5 nfsv3 will give you good info, on the VM itself are you using iostat or ?

It does not make sense, aligning should never cause increased latency unless something else odd is going on.

Is it write or read latency that's increased (or both)? Do you have atime updates disabled on your volume options (which can cause "other_ops" to increase, although it shouldn't change the latency).

Jeremy Page | Gilbarco Veeder-Root, A Danaher Company
Senior Technical Architect | IS Infrastructure Systems | Yahoo IM: jeremypage
Office:336-547-5399 | Cell: 336-601-7274 | 24x7 Emergency: 336-430-8151

On 10/17/2012 09:49 AM, Steffen Knauf wrote:

Hi,

 

a small update. After aligning some VM's, a couple of them are slower (disk latency is higher than 200ms). The NFS Storage, where the *.vmdk's are stored has a different lateny than the disk. Strange........

 

./mbralign --sparse /vmfs/volumes/chip4-vmware_data_nfs01/web02/web02-flat.vmdk

 

Part    Type          old LBA    New Start LBA      New End LBA     Length in KB

   P1      83               63               64           401626           200781

   P2      82           401625           401640          4482150          2040255

   P3      83          4482135          4482160        314568790        155043315

 

Any Ideas?

 

greets

 

Steffen

 

 

Von: Jeremy Page [mailto:jeremy.page@gilbarco.com]
Gesendet: Freitag, 28. September 2012 17:11
An: Steffen Knauf
Cc: 'Jeff Mohler'; toasters@teaparty.net
Betreff: Re: AW: AW: Raidgroupsize and I/O Performance

 

Aligning your VMDK files is the first thing I'd do for certain.  As was mentioned on other messages you should verify that the PAM cards will help so you can evaluate cost/benefit. For us they worked wonders but if you are write constrained then all the cache in the world is not going to help.

On 09/28/2012 11:05 AM, Steffen Knauf wrote:

Yes that's true. A strange thing is that VSC (4.0) and mbrscan show me different results:

 

/opt/ontap # ./mbrscan /vmfs/volumes/chip4-vmware_data_nfs01/openx-test01/openx-test01-flat.vmdk

mbrtools esxi version 1.0

--------------------

/vmfs/volumes/chip4-vmware_data_nfs01/openx-test01/openx-test01-flat.vmdk p1 (Linux)    lba:64  offset:32768    aligned:Yes

/vmfs/volumes/chip4-vmware_data_nfs01/openx-test01/openx-test01-flat.vmdk p2 (swap)     lba:401640      offset:205639680        aligned:Yes

/vmfs/volumes/chip4-vmware_data_nfs01/openx-test01/openx-test01-flat.vmdk p3 (Linux)    lba:16771888    offset:8587206656       aligned:Yes

 

I think i can delete the backup file?:

[Counter=2891433], Filename=vol_vm1/openx-test01/openx-test01-flat.vmdk-mbralign-backup

 

I rescan the datastores via VSC and get the result that openx-test01 is misaligned

 

And some mbrscans are not possible:

 

./mbrscan /vmfs/volumes/chip4-vmware_data_nfs01/openx-test03/openx-test03-flat.vmdk

Failed to open /vmfs/volumes/chip4-vmware_data_nfs01/openx-test03/openx-test03-flat.vmdk - [Device or resource busy]

 

Thanks for your help and have a nice weekend. I'm on holiday for 1 Week, so my response could be delayed.....

 

greets

 

Steffen

 



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