So the good news is : they're doing the right thing. The bad news :- you're now an I/O expert and all I/O issues belong to you. Cynical? Moi? Niall On Thu, Feb 16, 2012 at 6:58 PM, Radoulov, Dimitre <cichomitiko@xxxxxxxxx>wrote: > > A quick follow-up on this: > we requested again from the storage team and the HW vendor to double check > if partition sector alignment was "appropriate", > this time (after having called their experts ...) they confirmed that it > would be better to partition the disks using a different offset > for the first sector (128 instead of the default - 63 in this case). > > So thanks again Niall, > now I'm reading the articles you mentioned. > > > > Best regards > Dimitre > > On Thu, Feb 16, 2012 at 11:34 AM, Niall Litchfield > <niall.litchfield@xxxxxxxxx> wrote: > > Dimitre, >> >> "I wouldn't bother" is probably incorrect. The details will depend on the >> array stripe size, the sector sizes and probably the specific hardware. >> That >> said most vendors recommend the 1mb starting point for a partition >> because >> it has as a common divisor most of the usual allocation unit sizes and >> disk >> label sizes. I quite like this article >> http://blogs.msdn.com/b/**jimmymay/archive/2009/05/08/** >> disk-partition-alignment-**sector-alignment-make-the-** >> case-with-this-template.aspx<http://blogs.msdn.com/b/jimmymay/archive/2009/05/08/disk-partition-alignment-sector-alignment-make-the-case-with-this-template.aspx> >> written from a windows perspective with SQL in mind, but really the basic >> issue isn't software specific. FWIW Oracle, Microsoft and VMWare all >> recommend that you align your storage hardware with the FS/Volume >> manager so >> as to avoid doing multiple IO requests where a single request would do, >> references below. >> >> >> http://www.vmware.com/pdf/**Perf_Best_Practices_vSphere4.**0.pdf<http://www.vmware.com/pdf/Perf_Best_Practices_vSphere4.0.pdf> >> http://www.oracle.com/**technetwork/articles/systems-** >> hardware-architecture/lun-**alignment-163801.pdf<http://www.oracle.com/technetwork/articles/systems-hardware-architecture/lun-alignment-163801.pdf> >> >> http://support.microsoft.com/**kb/929491<http://support.microsoft.com/kb/929491> >> > > > -- Niall Litchfield Oracle DBA http://www.orawin.info -- //www.freelists.org/webpage/oracle-l