ONTAP Hardware

changing raidsize on production aggr



is it possible to change the raidsize live.

situation now is fas 2050c (7.3.2p4)  with 34 (1 TB sata disk), 17 to each head. created an aggr0 with default raidsize = 14, which then ends up with 12 data disks + 2 dp and 3 spares / head.

so when increasing the raidsize to 16 I could add 2 disks to the aggr0, leaving one dedicated spare/head.

big question, can the raidsize changed live? without data loss?



Yes you can change raid group sizes live


It can be grown live, and can always be changed. But if you shrink it, or you have existing full RAID groups (and it has started creating a new one), it won't change these.



You can customize the size of your RAID groups based on your requirements for data availability, performance, and disk utilization.

You change the size of RAID groups on a per-aggregate basis, by setting the raidsize aggregate option. You cannot change the size of individual RAID groups.

The following list outlines some facts about changing the raidsize aggregate option:

  • If      you increase the raidsize option, more disks or array LUNs will be added      to the most recently created RAID group until it reaches the new size.
  • All      other existing RAID groups in that aggregate remain the same size, unless      you explicitly add disks to them.
  • You      cannot decrease the size of already created RAID groups.
  • The      new size applies to all subsequently created RAID groups in that      aggregate.

Enter      the following command: aggr options aggr_name raidsize size


The following command changes the raidsize setting of the aggregate aggr3 to 16 disks or array LUNs:

aggr options aggr3 raidsize 16

When disks are added to an existing volume, the filer will attempt to keep the amount of data stored on each disk about equal.

By adding a minimum of three  disks at a time to a volume, the throughput to disk is increased by  providing more disks to write to at a given time.


thnx all. issue has been solved !