Archil disks use a high-speed, durable cache, to enhance the performance of working with data from Data Sources. When using Archil disks, you’re only charged for the data that’s actively being used and stored in this high-speed storage layer.
Archil’s high-speed storage layer is charged at a rate of $0.20 per GiB-month, resulting in savings of 80% over using traditional disks like EBS alone.

​
File Data

When reading data from a Data Source, Archil automatically caches the data on the high-speed storage layer. This data remains on the high-speed storage layer for up to 1 hour after your last access of the data. Writes to Archil disks are buffered into the high-speed storage layer for coalescing before being flushed to the data source. Recently written data will remain in the high-speed storage layer for up to 1 hour after it’s been flushed to the origin data source. The amount of data that’s stored in the high-speed storage layer may not exactly match the amount of data that’s been read or written to the disk. For example, Archil disks will intelligently prefetch and cache data from data sources as it’s being read, which can result in additional read traffic. Rapid overwrites to the same piece of data will also result in additional storage charges as the Archil storage asynchronously coalesces and flushes the writes to the origin data source.

​
File Metadata

Metadata accesses do not result in any file data becoming active. As a result, tools such as find or ls will not result in additional data caching charges. When writing to file metadata with POSIX commands such as rename or changing attributes, Archil counts each write operation as 32 KiB of active data until the change is propagated to S3.

​
Metering

Archil disks meter the amount of data in the high-speed storage layer each minute, and you are billed for the amount of data amortized over the course of the month. For example, if you store 100 GiB of data in the high-speed storage layer for half of a month, you will be billed for 50 GiB-months of storage.