# Error when changing the MaxAvailabilityZones on a rack

**URL:** <https://community.convox.com/t/error-when-changing-the-maxavailabilityzones-on-a-rack/79>\
**Category:** Rack (Version 2)\
**Created:** [February 13, 2019, 9:37am UTC](https://community.convox.com/t/error-when-changing-the-maxavailabilityzones-on-a-rack/79 "2019-02-13T09:37:11Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![eravelo](https://yyz1.discourse-cdn.com/flex029/user_avatar/community.convox.com/eravelo/32/22_2.png) [@eravelo](https://community.convox.com/u/eravelo)\
**Post date:** [February 13, 2019, 9:37am UTC](https://community.convox.com/t/error-when-changing-the-maxavailabilityzones-on-a-rack/79/1 "2019-02-13T09:37:11Z")

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When I try to increase the MaxAvailabilityZones  
`convox rack params set MaxAvailabilityZones=3 --wait`

I end up with an error I can’t understand

> 2019-02-13T09:22:59Z system/aws/cfm paas CREATE\_FAILED VolumeTarget2 The IAM identity making this call has an IAM policy that is too large. Reduce the size of the policy and try again. (Service: AmazonElasticFileSystem; Status Code: 400; Error Code: BadRequest; Request ID: f3eaba64-2f70-11e9-9a5e-8159ae28df8c)

Is there a way to change this setting, or do we have to re-create the rack?

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**Author:** ![nick](https://yyz1.discourse-cdn.com/flex029/user_avatar/community.convox.com/nick/32/43_2.png) [@nick](https://community.convox.com/u/nick)\
**Post date:** [March 19, 2019, 5:17pm UTC](https://community.convox.com/t/error-when-changing-the-maxavailabilityzones-on-a-rack/79/2 "2019-03-19T17:17:31Z")

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I also ran into this same issue when adjusting a rack that had MaxAvailabilityZones=2. So far I haven’t found a resolution, but will update if I do.

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**Author:** ![nick](https://yyz1.discourse-cdn.com/flex029/user_avatar/community.convox.com/nick/32/43_2.png) [@nick](https://community.convox.com/u/nick)\
**Post date:** [April 2, 2019, 8:55pm UTC](https://community.convox.com/t/error-when-changing-the-maxavailabilityzones-on-a-rack/79/3 "2019-04-02T20:55:50Z")

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I ended up solving this by applying the update directly in the AWS CloudFormation web dashboard (Update stack -\> Use current template -\> modify MaxAvailabilityZones along with AvailabilityZones, as needed). Convox successfully picks up the update once it’s complete.

Thanks to @ddollar for the help offline. He said this is a known AWS issue but they don’t currently have a timeline for a fix.