What are differences btw Virtual LUN, FAST and FAST VP?

if you want to manually move device between different pools or tiers

Then why or in what situations do I need to use Virtual LUN?

Virtual LUN is Thin LUN created on Thin Pool. The pool can have SSD/FC/SATA tiers with varying RAID Groups. FAST VP Moves hot bits of LUN to various drive types. You cant compare these technologies, they work together.

Shanmugas,

Technically this is true.. a TDEV is basically a Virtual LUN on top of a pool.  FASTVP can manage the tiering of a Virtual LUN (aka TDEV).

Most of the time however, when someone refers to VirtualLUN on VMAX, they are actually referring to VLUN Migration and it's just being shortened.  When referring to the LUN itself, most people say Host LUN, LUN, TDEV or Thin Device.  So the earlier replies on this original question assumed that emcmagic was referring to VLUN migration rather than just the VLUN.  This may have been an error on our part.

For Clarification..

STD or Device is a host LUN created from DATA devices (or hypers) of specific disks, not associated with a thin pool.  This is as close to a traditional LUN on RAID Group as you can get on Symmetrix.

TDAT or Thin Data devices are essentially hypers of specific disks that are aggregated to create a Thin Pool

VLUN and TDEV are synonymous, essentially a host LUN created from a Thin Pool

VLUN Migration is a manual operation used to move a Host LUN between pools or tiers

FAST is an automated service that tiers entire host LUNs between tiers based on workload

FASTVP is an automated service that tiers sub-LUN segments between tiers based on workload.

Hi Rich,

You understood my question correctly. Thanks for all your clarifications.

Now since you brought up, are there STD devices  in VMAX world as well? As far as I know, the closest one in VMAX is TDAT device, and we use it only for Thin pool, not to create LUN on it. We only use Thin device to bound thin pool, and then provision it to hosts. Am I correct here?

"someone refers to VirtualLUN on VMAX, they are actually referring to VLUN Migration and it's just being shortened." - I think that is pretty weird to call VirtualLUN for LUN migration. If someone refers like that in my company, I am going smack them. j/k

STD refers to standard device, created using hyper(s), basically a thick device. It is going to be one of the rare species in the future.

Yes, STD devices are supported on VMAX, but you'd essentially be doing that outside of, or instead of pools and TDAT/TDEVs.  You can have some disks configured outside a pool and create STD devices on them, and other disks in a pool.

VMAX10K systems support pools only, but 20K and 40K can support pools and STD devices.

symdev list ..pool devices will be listed as TDEVs, while thick devices will be listed based on their protection.IE: 2-Way Mirror or RAID-5

I did not know we could use STD, in addition to use POOL, although I don't know if there are any reasons to do so.

What commands to determine if we are using STD device on 20K?

gatekeepers can be TDEVs as well.

You should see at least few since Gatekeeper devices are Standard devices.

apparently someone in your shop decided to create traditional devices (STD) versus Thin devices (TDEVs). Why ? Could be due to old compatibility restrictions (SRDF from older DMX platforms). STD  is just a "nickname" for thick devices ..devices that are not bound to pools.

Yes, GK could be TDEV, so RAID5, RAID6, or 2-Way Mir.

I did "symdev list", which shows me RAID5, 2-Way Mirror etc. All these devices should be all created on TDEV devices, and bound to Thin Pool. So, they are not STD. right?

On Symmetrix, if it is STD device, should not it show you "STD"?

One more followup.

Isn't true that FAST VP only work on or with THIN POOLS? (SATA, FC, OR SSD POOLS)?