Supported and tested Microsoft iSCSI Software Target 3.3 limits

This topic provides the supported and tested Microsoft iSCSI Software Target 3.3 limits.

Applies to:   Windows Server 2012 R2
Original KB number:   2535811

Summary

The following tables display the tested limits and the enforced limits where applicable. In addition, the following limits apply:

  1. You should not use network adapter teaming with Microsoft iSCSI Software Target 3.3 for iSCSI communication.
  2. If you plan to use multiple network adapters for iSCSI communication, you should separate them into their own subnets, set up virtual IP addresses, and then implement MPIO.

Basic configuration

Item Limit Enforced Comment
iSCSI target instances per appliance 256 Not Enforced
Initiators that can connect to the same iSCSI target instance 16 Enforced When used with MPIO, you can connect no more than 4 sessions per initiator.
iSCSI initiators per appliance 256 Not Enforced
Virtual disks per appliance 256 Not Enforced
Virtual disks per iSCSI target instance 128 Enforced
Simultaneous sessions 64 Enforced
Snapshots per virtual disk 512 Enforced There is a limit of 512 snapshots per independent iSCSI application volume and 64 snapshots for file share volumes. If the iSCSI virtual disks and file shares are on a common volume, the iSCSI snapshot limit is 448 (512 - 64).
Locally mounted virtual disks or snapshots per appliance 32 (on stand-alone or snapshots per appliance) Enforced

Fault Tolerance

Item Limit Enforced Comment
Failover cluster nodes 5 Not Enforced
Error recovery level (ERL) 0 Enforced
Multiple Connections per Session (MCS) Not supported Enforced
Simultaneous connections 64 Not Enforced
Multipath Input/Output (MPIO) Supported N/A
MPIO Paths 4 Not Enforced
Virtual disks over MPIO per initiator on a stand-alone server 64 Not Enforced There is an initial delay after creating the disks before they appear to the Virtual Disk Service and the Disk Management snap-in because PnP first detects the devices and then MPIO detects the paths for each disk. This happens only one time per disk per appliance.
Virtual disks over MPIO per initiator on a clustered application server 32 Not Enforced
Converting stand-alone iSCSI Software Target to failover cluster or vice versa Supported N/A No VHD or target will be preserved.

Network

Item Limit Enforced Comment
Maximum number of active network ports 6 Not Enforced Applies to network ports that are dedicated to iSCSI traffic, rather than the total number of network ports in the appliance.
Network port speed 10 gigabits per second (Gbps) Not Enforced
IPv4 Supported
IPv6 Supported
TCP offload Supported
iSCSI offload Not Supported
Jumbo Frames Supported
IPsec Supported

iSCSI virtual disks

Item Limit Enforced
From an iSCSI initiator, which converts the iSCSI target disk from a fixed disk to a dynamic disk Not supported Not enforced
VHD minimum size format 8 MB Enforced
Parent VHD size 2088890 MB Enforced
Fixed VHd size 16776703 MB Enforced
Differencing VHD size 2088960 MB Enforced
VHD fixed format Supported N/A
VHD differencing format Supported N/A
VHD dynamic format Not supported N/A
FAT/FAT32 (hosting volume of VHD) Not supported Not enforced
NTFS Supported N/A
NTFS cluster size 4 kb N/A
Non-Microsoft CFS Not Supported Enforced
Number of differencing VHDs per VHD 256 Not enforced
Number of parent VHDs per differencing VHD 1 Enforced
Number of boot operating systems that can be installed on one VHD 1 Not enforced
Thin provisioning Not supported N/A
LUN shrink Not supported N/A
LUN cloning Not supported N/A

Windows operating systems on which the VDS and VSS hardware providers are supported

Operating System Limit Enforced
Windows Server 2003 R2 x64 Supported Enforced
Windows Server 2003 R2 x86 Supported Enforced
Windows Server 2008 SP2 x64 Supported Enforced
Windows Server 2008 SP2 x86 Supported Enforced
Windows Server 2008 R2 x64 Supported Enforced
Windows Storage Server 2008 x64 Supported Enforced
Windows Storage Server 2008 x86 Not supported Enforced
Windows Storage Server 2008 R2 x64 Supported Enforced
All client operating systems (Windows XP, Windows Vista, Windows 7) Not supported Enforced

iSCSI Software Target provider interoperability

iSCSI target version iSCSI provider version Supported
3.1 3.1 Supported
3.2 3.1 Not supported
3.2 3.1 (in-place upgrade) Not supported
3.1 3.2 Supported
3.2 3.2 Supported
3.2 3.3 Supported
3.3 3.3 Supported

Note: In-place upgrades from Microsoft iSCSI Software Target 3.1 to Microsoft iSCSI Software Target 3.3 are not supported. To upgrade to Microsoft iSCSI Software Target 3.3, you must first uninstall Microsoft iSCSI Software Target 3.1.

iSCSI Software Target virtual disk compatibility

Created in version Mounted in version Supported
3.0 3.1 Not supported
3.0 3.2 Supported
3.1 3.2 Supported
3.1 3.3 Supported
3.2 3.3 Supported

Microsoft iSCSI Software Target snap-in interoperability

Snap-in installed on Managing iSCSI target on Supported
Windows Storage Server 2008 R2 Windows Storage Server 2008 R2 Supported
Windows Storage Server 2008 R2, stand-alone server Windows Storage Server 2008 R2, failover cluster node Supported
Windows Storage Server 2008 R2, failover cluster node Windows Storage Server 2008 R2, stand-alone server Supported

Miscellaneous

Item Supported
Install Microsoft iSCSI Software Target 3.3 snap-in on Windows XP, Windows Vista, or Windows 7 Not supported
Install Microsoft iSCSI Software Target 3.3 snap-in on x86 version of Windows Storage Server 2008 Not supported
Use Microsoft iSCSI Software Target 3.3 snap-in to manage Microsoft iSCSI Software Target 3.2 target Supported
Use Microsoft iSCSI Software Target 3.2 snap-in to manage Microsoft iSCSI Software Target 3.3 target Not supported