Glyph cy-misan-v User Guide
27
Setting Up the miSAN
Cybernetics
UM-MV-86-B1-0801
the number of virtual tapes will destroy all data currently stored on them. Changing the numbers and
types of virtual devices may result in the need to reassign virtual tapes to the drives or stackers.
Changing the virtual device configuration does not affect the data currently stored on the virtual
tapes.
types of virtual devices may result in the need to reassign virtual tapes to the drives or stackers.
Changing the virtual device configuration does not affect the data currently stored on the virtual
tapes.
Deciding How Many Virtual Tapes to Create
Choosing the number of virtual tapes to create involves deciding how to allocate the available
miSAN-V-Series storage space. Factors to consider are the size of each physical tape, number
of disk drives used by the miSAN-V-Series, total miSAN-V-Series disk storage capacity, tape car-
tridge capacity, and historical/estimated compression ratio for backup data. For archiving effi-
ciency, the virtual tapes should closely match tape cartridges in capacity, and the number of
virtual tapes should completely use the miSAN-V-Series disk cache, as virtual tapes do not span
disk drives.
miSAN-V-Series storage space. Factors to consider are the size of each physical tape, number
of disk drives used by the miSAN-V-Series, total miSAN-V-Series disk storage capacity, tape car-
tridge capacity, and historical/estimated compression ratio for backup data. For archiving effi-
ciency, the virtual tapes should closely match tape cartridges in capacity, and the number of
virtual tapes should completely use the miSAN-V-Series disk cache, as virtual tapes do not span
disk drives.
Deciding What Kind of Virtual Tape Drives to Create
Deciding the number of virtual tape drives and stackers to create involves considering the
amount of data to be backed up, the intended backup schedule (e.g., incremental vs. full back-
ups), the time length of the backup window, and the number of backup host systems that can
send data. The miSAN-V-Series can be configured to create multiple virtual tape drives and
stackers, up to the purchased limit, and can support multiple simultaneous backup and restore
operations using the independent virtual devices.
amount of data to be backed up, the intended backup schedule (e.g., incremental vs. full back-
ups), the time length of the backup window, and the number of backup host systems that can
send data. The miSAN-V-Series can be configured to create multiple virtual tape drives and
stackers, up to the purchased limit, and can support multiple simultaneous backup and restore
operations using the independent virtual devices.
Note
The miSAN-V-Series emulates the IBM® 3580 LTO Ultrium tape drive for
virtual drives and the Overland™ NEO Series tape library for virtual
stackers. The IBM 3580 and Overland NEO are supported by nearly all
backup applications. Thus, virtual drives and stackers should be
recognized correctly by host backup software.
virtual drives and the Overland™ NEO Series tape library for virtual
stackers. The IBM 3580 and Overland NEO are supported by nearly all
backup applications. Thus, virtual drives and stackers should be
recognized correctly by host backup software.
Caution
Do not allow more than one backup host to access a virtual device at
the same time. Virtual tapes can become corrupted and data lost if
backup software on more than one host is allowed to access a virtual
device simultaneously. To prevent this, create a virtual device for each
host, and then configure “Device Visibility” so each host only sees its
own device.
the same time. Virtual tapes can become corrupted and data lost if
backup software on more than one host is allowed to access a virtual
device simultaneously. To prevent this, create a virtual device for each
host, and then configure “Device Visibility” so each host only sees its
own device.
Note
If the miSAN-V-Series is not configured with Tape Library Control
support, an external tape library will appear to the miSAN as a physical
standalone tape drive, rather than a physical stacker. Thus, a physical
library will be accessible by using a virtual standalone tape drive.
support, an external tape library will appear to the miSAN as a physical
standalone tape drive, rather than a physical stacker. Thus, a physical
library will be accessible by using a virtual standalone tape drive.