Virtual TapeServer 8.2 Release Notes

Installation and Configuration | 5
Virtual device emulation
VTS allows multiple hosts to perform simultaneous backups to the VTS server. However, the
number of simultaneous backups affects performance of each backup, so it is recommended to
limit the number of simultaneous backups.
Note Only the first channel of the SAS ports is used for VTD and VTL creation when the
port is configured as a virtual (target) mode port. If the port is configured as a physical
(initiator) mode port, all four channels in the port are available.
Tape drive emulation
VTS supports one virtual tape drive (VTD) per SCSI port and up to four VTDs per Fibre
Channel port. All together, a maximum of 32 VTDs are supported per VTS server. For best
performance, VTS can perform a maximum of 16 simultaneous backups at one time.
Note Virtual tape drives support up to 256KB (262144 byte) blocks.
Tape library emulation
Multiple virtual tape libraries (VTLs) are supported per VTS system. Again, the number of
simultaneous backups affects the performance of each backup, so it is recommended to limit
the number of simultaneous backups per VTL.
VTS supports one VTL per Fibre Channel or SCSI port with a maximum of 16 VTLs per
system (limited by the number of available ports on the system). It is recommended that a
maximum of four VTDs per Fibre Channel VTL or a maximum of one VTD per SCSI VTL is
configured.
Supported emulation types
The following standalone drive types are supported:
 Compaq Network Services Division 5257
 Tandem 519X
 Quantum SDLT320
 Quantum DLT7000
 IBM 3490
 HP Ultrium 1
 HP Ultrium 3
 IBM ULT3580-TD1
 IBM ULT3580-TD3
 IBM ULT3580-TD4
 ALP-LTO4