Hi Rwise,  You can nondisruptively rebind a device to a different pool without first unbinding it.  Rewriting data to an existing extent will not cause that extent to be moved.  To see the distribution of capacity/extents for your devices, just add the -detail flag to the original command you pasted above.  Thanks,  - Sean
To see what pool devices are bound to, we can use:  C:\>symcfg -sid 123 list -tdev -sg SG_XXX -gb  Enabled Capacity (Tracks) : 4285068096 Bound   Capacity (Tracks) :    4457040                   S Y M M E T R I X   T H I N   D E V I C E S ------------------------------------------------------------------------------                                          Total          Total       Compressed        Bound      Flgs      Total      Allocated       Written      Size/Ratio Sym  Pool Name    EMPT        GBs        GBs (%)        GBs (%)        GBs (%) ---- ------------ ---- ---------- ---------- --- ---------- --- ---------- --- 0879 FC           F..B       64.0       64.0 100       64.0 100       64.0   0 0889 SATA         F..B      128.0      127.9 100      127.9 100      127.9   0 0899 SATA         F..B       80.0        0.1   0        0.1   0        0.1   0 Total                  ---------- ---------- --- ---------- --- ---------- ---   GBs                       272.0      192.0   0      192.0   0      192.0   0  If a device is unbound from a pool, say SATA, and then rebound to FC, the data will remain intact, but the *extents* will also remain on SATA. Upon writing new extents, these will be written to the FC pool, but reading extents that are already on SATA will not change them. The 2 ways that I know to bind a device to a new pool are:  Unbind and Rebind to a new pool -> Existing extents remain on original pool, new extents are written to new pool. - Is there a way to do this without it becoming offline to the host? (presumably I cannot unbind a device while it is in a Masking View? or can I??). - If an existing extent is written do (a single btye say) will that whole extent be moved up to the FC pool, or will it remain on SATA ?  symmigrate to a new pool -> All extents will be migrated up to the new pool (I know that this is online and non-disruptive, so that's good)  With the above options in mind (i.e. a device can be bound to FC, but have a distribution of extents on FC or on SATA, or on other pools at the same time), is there a command that can show me the distribution of extents for a device? i.e. in the above, if device 879 had been unbound and moved up to the FC pool, 100% of it's extents would remain on SATA until specific extents are written at which time they will be moved to FC; it would be useful to be able to see that?
VMAX Extent Distribution