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Davide Poletto
Davide Poletto
1 Post

Pinned topic FS900 (AE3) Compression Ratio after V9000 Volume migration to another Pool

‏2019-04-01T15:47:59Z |

Hi all,


On a IBM V9000 (AC3) we migrated all volumes of Pool0 to Pool1 (with svctask migratevdisk -mdiskgrp Pool1 -vdisk xxx where xxx represents the vdisk), on AE3 (FS900) we noticed the Compression Ratio almost doubled from 2.55 - when vdisks were all on the Pool0 (sixteen mdisks, 2TB each one, 32TB total) - to 4.82 - now that all of our vdisks are on the Pool1 (just four mdisks, 8TB each one, 32TB total).


Will that Compression Ratio go down to 2.55 again as we were used to see?


When we will be able to delete the mdisks which belong to (void) Pool0?


Having free capacity, the migration to Pool1 was required to finally destroy Pool0 (once free) and let the new Pool1 (actually 4 mdisks) to be enlarged with another 4 8TB mdisks in order to reach 8 8TB = 64TB of provisioned capacity (at 85% we should stay below 70TB considering we have twelve Small Size flash modules on FS900).


Thanks, Davide.

Updated on 2019-04-01T15:59:17Z at 2019-04-01T15:59:17Z by Davide Poletto