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How many pblks (parameter blocks) are available to NetApp controllers or MultiStore vFilers?

Last Updated:

Applies to

Data ONTAP and earlier


How many SMB Parameter Blocks (pBlks) are available on my storage appliance?

Prior to the Data ONTAP 7.2.x, Common Internet File System Protocol (CIFS) had an available SMB pBlk pool of 1024.

Starting with Data ONTAP, NetApp storage appliances will have a base of 1024 for storage systems that have up to 1GB (gigabyte) of memory. If the storage appliance has more than 1GB of memory, then the number of pBlks will be calculated by the following formula: (total number of disks * 8).  If the result is a value less than 1024, then max pBlks will be set to 1024.


  • Filer1 (FAS2020 with 1GB of memory) has 104 total disks in an SPHA configuration:  Max pBlks will be set to 1024.
  • Filer2 (FAS3140 with 4GB of memory) has 126 total disks in an MPHA configuration:  126 * 8 = 1008.  Max pBlks will be set to 1024.
  • Filer3 (FAS3140 with 4GB of memory) has 168 total disks in an MPHA configuration:  168 * 8 = 1344.  Max pBlks will be set to 1344.


  • All maximum pBlk calculations are performed at system start-up.
  • Prior to 8.2.4, if a filer/cluster has new disks shelves hot-added, maximum pBlks will not change until the filer/cluster is rebooted.  See enhancement 368450.
  • All pBlks exist in a pool, which are shared by all vFilers in a MultiStore enabled storage appliance.
  • For HA pairs, disks counted in the calculation include both local and partner disks.

For a complete list of ONTAP releases which use the new formula for provisioning pBlks, see the fixes list for BUG 223732.

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