新版本vsphere支持最大单个vmdk超过2T，理论上支持最大62T


In vSphere 5.5, large capacity virtual disks have these conditions and limitations:
An ESXi 5.5 or later host is required.
The maximum supported VMDK size on an VMFS-5 datastore is increased to 62 TB. However, the maximum supported VMDK size on VMFS-3 is still 2 TB.
The maximum supported size of a VMDK on NFS is the lesser of 62 TB and 1% less than the maximum file size supported by the NFS filesystem.

Notes:
The largest file size depends on the underlying file system (for example, 16 TB on ext3).
A maximum of of 62 TB is enforced, even if the underlying NFS filesystem supports a greater size.

The maximum supported size of a virtual mode Raw Device Mapping (vRDM) has also been increased from2 TB to 62 TB.
A VMDK larger than 2 TB can be created on a virtual machine that is powered on or off, but extending a VMDK beyond 2 TB is only supported when the virtual machine is powered off.
You must use the vSphere Web Client to create or extend a VMDK beyond 2 TB. For more information, see the Troubleshooting section of this article.
中文大意：

在 vSphere 5.5 中，大容量虚拟磁盘具有以下条件和限制：
需要 ESXi 5.5 或更高版本的主机。
VMFS-5 数据存储中支持的最大 VMDK 大小增加到 62 TB。但是，在 VMFS-3 中支持的最大 VMDK 大小仍为 2 TB。
NFS 中支持的最大 VMDK 大小低于 62 TB 并且比 NFS 文件系统支持的最大文件大小小 1%。

注意：
最大文件大小取决于基本文件系统（例如，在 ext3 上为 16 TB）。
最大大小强制为 62 TB，即使基础 NFS 文件系统支持更大的尺寸。

虚拟模式裸设备映射 (vRDM) 支持的最大大小已从 2 TB 增加至 62 TB。
可以在打开或关闭电源的虚拟机中创建大于 2 TB 的 VMDK，但在关闭虚拟机电源时仅支持扩展（不是创建）超过 2 TB 的 VMDK。
必须使用 vSphere Web Client 创建或扩展超过 2 TB 的 VMDK。有关详细信息，请参见本文的“故障排除”部分。


Virtual machines with large capacity disks have these conditions and limitations:
The guest operating system must support large capacity virtual hard disks.
You can only move or clone disks that are greater than 2 TB to ESXi 5.5 hosts, or to clusters that have such hosts available. 
The datastore format must be VMFS-5 or later, or an NFS volume on a Network Attached Storage (NAS) server.
vSphere Flash Read Cache supports a maximum hard disk size of 16 TB.
VMFS-3 volumes are not supported. You cannot move disks greater than 2 TB from a VMFS-5 datastore to a VMFS-3 datastore.
You cannot hot-extend a virtual disk if the capacity after extending the disk is equal to or greater than 2 TB. Only offline extension of GPT-partitioned disks beyond 2 TB is possible.
Fault Tolerance is not supported.
Virtual SAN is not supported.
BusLogic parallel controllers are not supported.
Virtual machines with large capacity virtual hard disks or disks greater than 2 TB must meet resource and configuration requirements for optimal virtual machine performance. The maximum value for large capacity hard disks is 62 TB. When you add or configure virtual disks, always leave a small amount of overhead. Some virtual machine tasks can quickly consume large amounts of disk space, which can prevent successful completion of the task if the maximum disk space is assigned to the disk. Such events might include taking snapshots or using linked clones. These operations cannot finish when the maximum amount of disk space is allocated.
In environments without shared storage, operations such as snapshot quiesce, cloning, Storage vMotion, or vMotion can take significantly longer to finish.
You cannot relocate RDMs larger than 2 TB to datastores other than VMFS-5 or, to hosts older than ESXi 5.5.
To enable the Microsoft Windows operating system to address a maximum storage capacity for a device greater than 2 TB, the disk must be initialized by using the GUID partition Table (GPT) partitioning scheme. For more information, see Windows support for hard disks that are larger than 2 TB.
中文大意:

具有大容量磁盘的虚拟机会有以下条件和限制：
客户机操作系统必须支持大容量虚拟硬盘。
您只能将大于 2 TB 的磁盘移动或克隆到 ESXi 5.5 主机，或具有此类可用主机的群集。
数据存储格式必须是 VMFS-5 或更高版本，或网络附加存储 (NAS) 服务器上的 NFS 卷。
vSphere Flash Read Cache 支持的最大硬盘大小为 16 TB。
不支持 VMFS-3 卷。无法将大于 2 TB 的磁盘从 VMFS-5 数据存储移动到 VMFS-3 数据存储。
如果扩展磁盘后的容量等于或大于 2 TB，则无法热扩展虚拟磁盘。仅支持超过 2 TB 的 GPT 分区磁盘的脱机扩展。
不支持 Fault Tolerance。
不支持 Virtual SAN。
不支持 BusLogic 并行控制器。
具有大容量虚拟硬盘或大于 2 TB 磁盘的虚拟机必须满足最佳虚拟机性能的资源和配置要求。大容量硬盘的最大值为 62 TB。添加或配置虚拟磁盘时，始终保留少量开销。某些虚拟机任务会很快地消耗大量磁盘空间，因此，如果向该磁盘分配了最大磁盘空间，则会妨碍任务的成功完成。此类事件可能包括生成快照或使用链接克隆。如果分配了最大磁盘空间，这些操作将无法完成。
在无共享存储的环境中，某些操作（如快照静默、克隆、Storage vMotion 或 vMotion）可能需要较长时间才能完成。
不能将大于 2 TB 的 RDM 重定位到除 VMFS-5 以外的数据存储，或低于 ESXi 5.5 版本的主机。
要支持 Microsoft Windows 操作系统解决最大存储容量超过 2 TB 的设备，则必须使用 GUID 分区表 (GPT) 分区方案初始化该磁盘。有关详细信息，请参见 Windows support for hard disks that are larger than 2 TB。



Note: The preceeding link was correct as of June 13, 2014. If you find the link is broken, please provide feedback and a VMware employee will update the link.
Changes in virtual machine snapshots for VMDKs larger than 2 TB:
Snapshots taken on VMDKs larger than 2 TB are now in Space Efficient Virtual Disk (SESPARSE) format. No user interaction is required. The redo logs will be automatically created as SESPARSE instead of VMFSSPARSE (delta) when the base flat VMDK is larger than 2 TB.
Extending a base flat disk on VMFSSPARSE or SESPARSE is not supported.
The VMFSSPARSE format does not have the ability to support 2 TB or more.
VMFSSPARSE and SESPARSE formats cannot co-exist in the same VMDK. In a virtual machine, both types of snapshot can co-exist, but not in the same disk chain. For example, when a snapshot is taken for a virtual machine with two virtual disks attached, one smaller than 2 TB and one larger than 2 TB, the smaller disk snapshot will be VMFSSPARSE the larger disk snapshot will be SESPARSE.
Linked clones will be SESPARSE if the parent disk is larger than 2 TB.

大于 2 TB 的 VMDK 的虚拟机快照中的更改：
在大于 2 TB 的 VMDK 上生成的快照目前采用节省空间的虚拟磁盘 (SESPARSE) 格式。无需进行任何用户交互。如果基本平面 VMDK 大于 2 TB，则重做日志将自动以 SESPARSE 格式创建，而不是 VMFSSPARSE（增量）。
不支持采用 VMFSSPARSE 或 SESPARSE 格式扩展基本平面磁盘。
VMFSSPARSE 格式不支持 2 TB 或更多空间。
VMFSSPARSE 和 SESPARSE 格式不能共存在同一个 VMDK 中。在虚拟机中，快照的两种类型可以共存，但不可以在同一个磁盘链中。例如，如果对已连接两个虚拟磁盘的虚拟机生成快照，一个磁盘小于 2 TB，另一个磁盘大于 2 TB，则较小的磁盘快照将为 VMFSSPARSE，较大的磁盘快照将为 SESPARSE。
如果父磁盘大于 2 TB，则链接克隆将为 SESPARSE。


Troubleshooting
When you attempt to extend a VMDK beyond 2 TB on a powered on virtual machine, you see this error in the client:

Hot-extend was invoked with size (*** sectors) > =2TB. Hot-extend beyond or equal to 2TB is notsupported. This disk extend operation failed: msg.disklib.INVAL

To resolve this issue:

Power off the virtual machine and retry the extend operation.
Detach the VMDK from the original virtual machine and attach to any other powered off virtual machine and then increase the size to the desired size. Detach the VMDK from the temporary powered off vm and attach back to the original Virtual machine

When you attempt to create a large virtual disk on a VMFS-3 datastore or on NFS using ext3, you see this error in the vSphere Client or when using vmkfstools:

Failed to create virtual disk: The destination file system does not support large files (12).

When you attempt to create a large VMDK using the vSphere Client, you see the error:

The disk capacity entered was not a properly formed number or was out of range. It has been replaced with the nearest acceptable value
DiskCapControl : value 6924239004288 is out of range (1048576,4398046511104)

Checking the size of the newly created or expanded VMDK, you find that it is 4 TB.

那么问题来了

如果尝试在已打开电源的虚拟机上扩展超过 2 TB 的 VMDK，则会在客户端看到以下错误：

已调用大小大于等于 2TB（*** 个扇区）的热扩展。不支持大于或等于 2TB 的热扩展。此磁盘扩展操作失败：msg.disklib.INVAL (Hot-extend was invoked with size (*** sectors) > =2TB. Hot-extend beyond or equal to 2TB is not supported. This disk extend operation failed: msg.disklib.INVAL)

要解决此问题，请执行以下操作：
关闭虚拟机电源并重试扩展操作。
将 VMDK 与原始虚拟机分离，并连接到任何其他已关闭电源的虚拟机，然后将大小增加到所需大小。将 VMDK 与临时关闭电源的虚拟机分离，然后重新连接到原始虚拟机

尝试在 VMFS-3 数据存储或使用 ext3 的 NFS 上创建大虚拟磁盘时，您会在 vSphere Client 中或使用 vmkfstools 时看到以下错误：

无法创建虚拟磁盘：目标文件系统不支持大文件 (12) (Failed to create virtual disk: The destination file system does not support large files (12).)。

尝试使用 vSphere Client 创建大 VMDK 时，您会看到以下错误：

输入的磁盘容量数值格式不正确或超出范围。该值已替换为最接近的可接受值
DiskCapControl：值 6924239004288 已超出范围（1048576 至 4398046511104） (The disk capacity entered was not a properly formed number or was out of range. It has been replaced with the nearest acceptable value DiskCapControl : value 6924239004288 is out of range (1048576,4398046511104))

检查最新创建或已扩展 VMDK 的大小，您会发现该大小为 4 TB。