Tom Creighton Considerations Regarding Archival Cloud Storage

So You Think You Want To Do It In The Cloud? Service Availability Data Durability & Integrity Service and Data Security Access Methods COST

Service Availability Amazon aws – 99.9% availability guarantee (S3) – Regional – Inter-regional availability probably higher – Few inter-regional services Rackspace – Cloud Files 100% – Credits based on sliding scale of errors returned Gartner did not like HP or aws SLAs but really was about compute

Data Durability AWS S3 & Glacier offer % durability – Store 10,000 objects you’ll lose one every 10,000,000 years. (10 4 objects * err/obj/yr = err/yr) – Store 1 billion objects, you’ll lose one object every 100 years – Synchronous read after write – Eventual consistency of copy – Periodic fixity checks

Data Durability AT&T (EMC Atmos) Erasure coding + replica – 9/12 Configuration 9 data fragments 3 coding fragments % durability Tolerate 3 drive loss – 10/16 Tolerate 6 drive failures % durability ?? 60% overhead Lower write performance

Service & Data Security SSL Privacy on access SHA-256 tree hash on archive upload (integrity) Encryption transparent – Amazon manages encryption key (AES-256) – Key per object – Future might allow customer managed key

AWS Security Certifications See aws.amazon.com/security Compliance – SOC 1 (SAS70), SOC 2, SOC 3 – PCI DSS Level 1 – ISO – FedRAMP – ITAR – FIPS – Others

Access Methods REST – Via S3 Object names then apply Upload is via S3 Lifecycle policies for migration Retrieval via Glacier request, then S3 – Direct User does not provide name – Glacier provides ID Synchronous write; asynchronous request SHA-256 has of all 1MB blocks of an archive on upload

Simple Comparison 3 Scenarios over 10 years – Start: 0 TB, Increase 1 TB/Month – Start: 10 TB, Increase 5 TB/Month – Start: 100 TB, Increase 10 TB/Month Compare Online Cloud Storage – AWS: S3 & Glacier – AT&T: Dynamic & Negotiated – Rackspace (Open Cloud) No access charges included No price reductions reflected

Start 0 TB, Increase 1TB/Month

Start 10TB, Increase 5TB/Month

Start 100TB, Increase 10TB/Month

Questions?