advantages and disadvantages of VMFS extents

[MLaskowski012]

Can somebody explain to me any advantages and disadvantages of using VMFS extents VS creating larger LUN's on the SAN level?

[mike_laspina]

Hello,

A few things come to mind.

1.One inaccessable LUN can kill the entire vmfs volume.

2. Requires more LUN mappings across ESX hosts.

3. Metadata files sit on one LUN and not the extents which could lead a funnel of SCSI reservation conflicts.

I can't think of any advantages other than you do not need to move VM's around to keep things alive.

[Patrick_Miller]

100% agree with Mike. As far as I am concerned, extents should be avoided if at all possible.