Expanding 16 TB volume using Windows dynamic disks

Question

We have a 16 TB volume that lives on a SAN LUN attached to a Windows 2008 file server. We are unable to expand the SAN LUN any further on it's current SAN and will need to have our storage team purchase an additional SAN enclosure to add capacity. With that said does anyone have experience with converting an existing basic Windows volume into a dynamic disk so that we may expose several new LUNs and use dynamic striped or spanned disks so that we may increase the capacity of our drive? Will this take forever? Is there a great chance of corruption?

Additionally the per fsutil the current 16 TB volume is using a 4KB cluster size. Will this limit the size without formatting?

 C:\Users\admin\ fsutil fsinfo ntfsinfo d:
 NTFS Volume Serial Number :       0x9246519846517e43
 Version :                         3.1
 Number Sectors :                  0x00000007cffbefff
 Total Clusters :                  0x00000000f9ff7dff
 Free Clusters  :                  0x000000001b1c8f40
 Total Reserved :                  0x0000000000000000
 Bytes Per Sector  :               512
 Bytes Per Cluster :               4096
 Bytes Per FileRecord Segment    : 1024
 Clusters Per FileRecord Segment : 0
 Mft Valid Data Length :           0x00000000ac420000
 Mft Start Lcn  :                  0x00000000000c0000
 Mft2 Start Lcn :                  0x000000007cffbeff
 Mft Zone Start :                  0x00000000eacadbe0
 Mft Zone End   :                  0x00000000eacb82a0
 RM Identifier:        6CBB62D9-FE1A-11E2-9628-D89D672B218F

Thanks for any info!

Looks like you change cluster size, any experience with how long something like that would take? — floyd, Sep 04 '16 at 19:32

score 1 · Accepted Answer · answered Sep 05 '16 at 03:38

Yes, 16TB is the largest you can get with a 4K cluster size, as Greg Askew mentioned. You can change your cluster size, but it takes forever. You can also change your basic disk to a dynamic disk easily via the disk manager. After you convert it, you can expand the dynamic disk group using additional LUNs. The filesystem sits atop the disk group, allocating data to all block device members in the disk group. You can use a linear allocation policy (default), or you may set up a software raid if that is appropriate for this. Linear is probably what you want, since this is coming from a SAN host.

Beware, if this LUN or any other LUN in this dynamic disk group is provided via the Windows software iscsi initiator (rather than a specialized HBA), it will fail to start on boot (requiring manual activation on every boot using disk management). It will work after manual activation, though.

The boot time activation problem is due to dynamic disk services starting before software iSCSI initiator services.

Expanding 16 TB volume using Windows dynamic disks

1 Answers1