Normally runs as a VM on-premises (or hardware appliance)
Acts as bridge between storage that exists on-premises and AWS
Presents storage using iSCSI, NFS or SMB
On AWS integrates with EBS, S3 and Glacier
Storage gateways is used for migrations, extensions, storage tiering, DR and replacement of backup systems
Volume Gateway
Offers 2 different types of operation:
Volume Stored Mode:
The virtual appliance presents volumes over iSCSI to servers running on-premises (similar to what NAS/SAN hardware would)
Servers can create files systems on top of these volumes and use it in a normal way
These volumes consume capacity on-premises
Storage gateway has local storage, used as primary storage, everything is stored locally
Upload buffer: any data written to the local storage is also copied in the upload buffer and it will be uploaded to the cloud asynchronously via the storage gateway endpoint
The upload data is copied into S3 as EBS snapshots which can be converted into EBS volumes
It is great to do full disk backups, offering excellent RTO and RPO values
Volume Stored Mode does not allow extending the data center capacity! The full copy of the data is stored locally
Volume Cached Mode:
Volume Cached Mode shares the same basic architecture with Stored Mode
The main location of data is no longer on-premises, it is on AWS S3
It has a local cache for the data only storing the frequently accessed data, the primary data will be in S3
The data will be stored in AWS managed area of S3, meaning it wont be visible using the AWS console. It can be viewed from the storage gateway console
The data is stored in raw block state
We can create EBS volumes out of the data
Volume Cached Mode allows for an architecture know as data center extension
Tape - VTL Mode
VTL - Virtual Tape Library
Examples of tape backups: LTO-9 (Linear Tape Open) Media which can hold 24TB raw data per tape
Tape Loader (Robot): robot arm can insert/remove/swap tapes
A Library is 1 ore more drives, 1 or more loaders and slots
Traditional tape backup architecture:
Storage Gateway Tape (VTL) Mode architecture:
A Virtual tape can be from 100 GiB to 5 TiB
A Storage Gateway can handle at max 1PB ot data across 1500 virtual tapes
When virtual tapes are not used, they can be exported in the backup software marking them not being in the library (equivalent of ejecting them and moving them to the offsite storage)
When exported, the virtual tape is archived in the Virtual Shelf which is backed by Glacier
Storage Gateway in VTL Mode pretends to be a iSCSI tape library, tape change and iSCSI drive (physical tape backup system)
Use cases:
On-premises data storage extension into AWS
Migration of historical sets a tape backups
File Mode
Storage Gateway manages files in File Mode
File Gateway bridges on-premises file storage and S3
With File Gateway we create one or more mount points (shares) available via NFS or SMB
File Gateways maps directly onto on S3 bucket above which we have visibility from the AWS console
File Mode uses Read an Write Caching ensuring LAN-like performance
File Gateway architecture:
For Windows environments we can use AD authentication to access the File Gateway
File Mode can be used for multiple contributors (multiple shares on-premises)
File paths in a File Gateway map directly to S3 object names
NotifyWhenUploaded: API to notify other gateways when objects are changed
File Gateway does not support any kind of object locking => one gateway can override files from another gateway. We should use a read only mode on other shares or tightly control file access
The bucket backing the File Gateway can be used with cross-region replication (CRR)
The lifecycle policies can also be used for files to be moved automatically between classes
