3PAR tdvv to tdvv3 .

[kahna]

Hi

W would like to change 3PAR system so that old tdvv volumes and CPGs would use new decoV3 possibilities.

We have upgraded system to 3.3.1 os with all latest patch. But we only have 15% (not 50%) of free SSD space to use. How to achieve this goal?

regards, Kahna

[LiefB]

Kahna,

Ensure the system is running 3.3.1 EMU1 plus patches P21 and P25

Add drives to the array to provide the additional space needed to convert the volumes

Create a new CPG for the TDVV3 volumes

Once the volumes are converted use the checkvv -compr_dryrun command against the volumes you are considering for compression

Reference the document links below for further information

Thin Technologies White Paper

Adaptive Data Reduction Technologies

[kahna]

Hi

Know all the information You gave. Thanks for sharing.

Still the question remains:

But we only have 15% (not 50%) of free SSD space to use. How to achieve this goal?

The wanted answer does not start with : Add drives, buy new, delete data, attach an external disk, or similar. These are not an option.

There is a lots of empty space in the system, how come OS can't handle this conversion like all the other tunings? But instead it needs 50% empty space!!

50 % is a huge amount of extra space, You agree?

[Wesley Gulden]

You need space to to tune volumes to a different type. (i.e tdvv to tdvv3).

WIthout SSD space you option is to tune the TDVV volums to TPVV in a different CPG (FC or NL) and then after ALL TDVVs are tuned out of the SSD CPG and the dds is deleted, tune the TPVV volumes back to TDVV3.

IF you do not have space in another tier, then the tune to TDVV3 can not be accomplished unless you add space or free up sapce in the array.

The 50% value is an estimate and based on the size of the volumes you want to tune will dictate how much space you really need.

As it tunes it will create NEW LDs to copy data to that is why it requires additional space.

[Sheldon Smith]

Would the Slice Threshold and Slice Size options help here?