vsphere-esxi-vcenter-server-55-storage-guide

Chapter 27 Using vmkfstoolsWhen upgrading the datastore, use the following command: vmkfstools -T|--upgradevmfs /vmfs/volumes/UUIDNOTE All hosts accessing the datastore must support VMFS5 . If any ESX/ESXi host version 4.x or earlier isusing the VMFS3 datastore, the upgrade fails and the host's mac address is displayed. with the Mac addressdetails of the Host which is actively using the DatastoreVirtual Disk OptionsVirtual disk options allow you to set up, migrate, and manage virtual disks stored in VMFS and NFS filesystems. You can also perform most of these tasks through the vSphere Web Client.Supported Disk FormatsWhen you create or clone a virtual disk, you can use the -d --diskformat suboption to specify the format forthe disk.Choose from the following formats:• zeroedthick (default) – Space required for the virtual disk is allocated during creation. Any dataremaining on the physical device is not erased during creation, but is zeroed out on demand at a latertime on first write from the virtual machine. The virtual machine does not read stale data from disk.• eagerzeroedthick – Space required for the virtual disk is allocated at creation time. In contrast tozeroedthick format, the data remaining on the physical device is zeroed out during creation. It mighttake much longer to create disks in this format than to create other types of disks.• thin – Thin-provisioned virtual disk. Unlike with the thick format, space required for the virtual disk isnot allocated during creation, but is supplied, zeroed out, on demand at a later time.• rdm:device – Virtual compatibility mode raw disk mapping.• rdmp:device – Physical compatibility mode (pass-through) raw disk mapping.• 2gbsparse – A sparse disk with 2GB maximum extent size. You can use disks in this format with hostedVMware products, such as VMware Fusion, Player, Server, or Workstation. However, you cannotpower on sparse disk on an ESXi host unless you first re-import the disk with vmkfstools in acompatible format, such as thick or thin.See “Migrate Virtual Machines Between Different VMware Products,” on page 265.NFS Disk FormatsThe only disk formats you can use for NFS are thin, thick, zeroedthick and 2gbsparse.Thick, zeroedthick and thin formats usually behave the same because the NFS server and not the ESXi hostdetermines the allocation policy. The default allocation policy on most NFS servers is thin. However, onNFS servers that support Storage APIs - Array Integration, you can create virtual disks in zeroedthickformat. The reserve space operation enables NFS servers to allocate and guarantee space.For more information on array integration APIs, see Chapter 24, “Storage Hardware Acceleration,” onpage 235.Creating a Virtual DiskUse the vmkfstools command to create a virtual disk.-c --createvirtualdisk size[kK|mM|gG]-a --adaptertype [buslogic|lsilogic|ide|lsisas|pvscsi] srcfile-d --diskformat [thin|zeroedthick|eagerzeroedthick]VMware, Inc. 263