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Aligning SFW-HA 5.1 Volumes on NetAPP TP LUN

I've created a thin-provision Windows 2008 LUN on the NetApp (OnTap 7.3.3) and presented it to our SFW-HA 5.1 sp2 Windows 2008 R2 cluster (using the VNETAPP DMP-DSM) but cannot create an "aligned" volume even though track alignment support is enabled. 

In VEA's control panel under Track Alignment Settings, Track Alignment support is enabled but there  is not an entry for the NetApp to choose.

1 Solution

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Accepted Solution!

Hi Dave, As Mike stated,

Hi Dave,

As Mike stated, changes in the track alignment settings in VEA will affect new volumes only.

I think we are going about this the wrong way.  Netapp assumes that any volumes created on it will be created at the default windows offset of 63 blocks (2003 and earlier.)  Netapp aligns the lun on the backend so that a 63 sector offset is track aligned on the hardware.  As a result there is no need to do any track alignment from with SFW.  The track alignment setting in VEA/SFW can be ignored (default disabled) since Netapp is handling the physical track alignment on their end.

Track alignment is always done in number of blocks in SFW.  There would not be a recommendation for a 64KB offset in SFW.  When SFW recommends an offset of 64 blocks that equates to 32KB (standard 512 bytes per block/sector in windows.)

When dealing with SQL, it is recommended that the filesystem be formated with a 64KB Allocation Unit Size or Cluster Unit Size.  This optimizes the filesystem to handled 64KB writes that SQL does (1 extent = 8 pages = 8 X 8KB/page = 64KB.)  The Allocation Unit Size is set during the initial format of the volume and can only be changed by reformating the volume.

I hope this better explains what you are seeing.

 

Thanks,

Wally

 

 

 

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Hi Dave,   Netapp arrays

Hi Dave,

 

Netapp arrays typically handles track alignment needs based on the default starting volume offset of 63 sectors.  There is no need to worry about track alignment when using Netapp arrays.   As such, SFW does not have a track alignment setting for Netapp Arrays. 

Thanks,

Wally

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Wally,     Sorry I was

Wally,

    Sorry I was traveling over the extended holiday.     I'm not sure I entirely understand what I'm seeing.   In VEA's Track Alignment settings "Default" was not previously enabled.   Now once I have enabled the default setting the new volumes I create show as being "Aligned".   :-)

However in the NetApp diagnostic tool under SAN settings it's complaining that the LUN I created is misaligned and warning that it's file system is not a multiple of 4k.   When I created the volume I picked a 64k size as I've seen recommended for SQL databases. 

I'm thinking I need to call NetApp next ?

Dave

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I think the "aligned" status

I think the "aligned" status just indicates that new volumes will be aligned. It doesn't affect existing volumes.

64k is actually a multiple of 4k, so the error is confusing. Did they mean that the disk offset of the volume needs to be a multple of 4?

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Accepted Solution!

Hi Dave, As Mike stated,

Hi Dave,

As Mike stated, changes in the track alignment settings in VEA will affect new volumes only.

I think we are going about this the wrong way.  Netapp assumes that any volumes created on it will be created at the default windows offset of 63 blocks (2003 and earlier.)  Netapp aligns the lun on the backend so that a 63 sector offset is track aligned on the hardware.  As a result there is no need to do any track alignment from with SFW.  The track alignment setting in VEA/SFW can be ignored (default disabled) since Netapp is handling the physical track alignment on their end.

Track alignment is always done in number of blocks in SFW.  There would not be a recommendation for a 64KB offset in SFW.  When SFW recommends an offset of 64 blocks that equates to 32KB (standard 512 bytes per block/sector in windows.)

When dealing with SQL, it is recommended that the filesystem be formated with a 64KB Allocation Unit Size or Cluster Unit Size.  This optimizes the filesystem to handled 64KB writes that SQL does (1 extent = 8 pages = 8 X 8KB/page = 64KB.)  The Allocation Unit Size is set during the initial format of the volume and can only be changed by reformating the volume.

I hope this better explains what you are seeing.

 

Thanks,

Wally

 

 

 

View solution in original post

Aligning SFW-HA 5.1 Volumes on NetAPP TP LUN

Hi Dave,

I agree with Wally that in most cases, the NetApp Array will handle the track alignment settings for any new volumes created.

However, in your case, NetApp Support recommended that you use the Default (Generic JBOD) setting in the VEA Control Panel with the setting of 1024 Track Alignment Offset for your NetApp 3140 Array.

It is important to note that the Default setting in the VEA Control Panel Track Aligment settings is disabled by default and should only be used in specific scenarios. By default, SFW detects the Storage Array by the Vendor and Product IDs to apply Track Alignment settings. If a specific Storage Array is not detected, SFW will use what Wally is describing - the Default Windows offset of 63 blocks.