SCSI Storage Devices
An AEM-1 System always requires a primary SCSI storage device and may require one or more additional devices for split media support or internal copy/backup. Because of the variety of SCSI products available, all AEM SCSI devices must be defined separately from the AEM.
The usual choice for the primary storage device is a hard drive. The drive may be in a fixed internal mounting or in a removable drive canister.
Note: As of December 2005, 50 pin drive models (DRV-45 and DRV-45R) have been discontinued as the 50 pin drive bays and canisters to support them are no longer available. All current AEM models use 80 pin hard drives as primary storage devices in both fixed and removable enclosures (DRV-45 and DRVM-45R). Drives are not interchangeable. Existing AEMs may be retrofit to support the 80 pin drives. Contact your Arraid Representative for details.
Magneto-Optical drives have proven successful as the primary storage device in many applications, especially when used in a fully cached AEM-1C. Excellent as internal copy/backup devices, these drives and media have the durability to perform well for many years. MO devices are only available for fixed mounting.
Arraid also supports DDS3 DAT drives as internal backup devices.
Internal Options - Copy/Backup
The AEM-1 supports a number of internal options that provide the capability to copy the legacy disk image from the primary SCSI device to a second SCSI device. The copying takes place internally to the AEM, and is independent of the Customer's operating software or hardware. Usually used for system backup, these options can greatly reduce or eliminate the need for a magnetic tape drive on the system.
- Disk-to-Disk Off-Line Copy - Allows the User to clone emulated disk images from the primary SCSI device to a second, usually identical, SCSI device for backup purposes.
- Disk-to-Cartridge Media Disk Off-line Copy - Allows the User to clone emulated disk images from the primary SCSI device to a second SCSI device, such as an MO cartridge disk, for backup or distribution of media among similar systems.
- Disk-to-Tape Off-line Backup - Allows the User to create a backup copy of the emulated disk image on DAT.
- Disk-to-Disk On-Line Copy - Similar to mirroring, the AEM automatically maintains two copies of the emulated image on two SCSI hard drives for added reliability and fault tolerance.
- Disk-to-Cartridge Media Disk On-line Copy - Allows the User to clone emulated disk images from the primary SCSI device to a second SCSI device, such as an MO cartridge disk, without taking the AEM off-line.
- Combinations of Above Options
Other Internal Options
- Dual Port SMD Interface - Allows two computers to access the same disk drive. Only required if the original drive was dual ported.
- Fixed/Removable Emulation - Emulates those drives where the drive capacity is split between fixed platters and a removable cartridge.
- Multi-Volume Support - Allows storage of multiple legacy disk images on one SCSI device.
- Additional Crystals - The crystal controls the drive transfer rate. In cases where a spare drive must be reconfigurable to emulate several different legacy models in use, the Customer may require additional crystals.
- Additional Track Buffers - Depending upon the Customer's application, caching a larger portion of the disk emulation in additional track buffers may improve performance.
- Interface Connectors - Older SMD drives used large Amphenol block connecters rather than the now standard IDC.
External Options
- Interface Cables
- Cable Termination
- Mounting Shelf
- EU Certification
Contact your Arraid Representative for advice and assistance in selecting AEM-1 Devices and Options.