On August 11th, at 13:34 UTC, we were notified of limited Block Storage capacity in our Washington DC (us-iad) data center. This prevented customers from provisioning new volumes. Once notified of this issue, we worked to add additional capacity and return the Block Storage service back to expected thresholds to meet demand.
By August 12th, 00:00 UTC, additional capacity had been made available and we resolved the storage capacity issue.
In addition to adding more capacity for our Washington DC data center, we also have made adjustments to our monitoring tools and capacity management policies to help mitigate future availability issues.