HP StoreEver MSL2024, MSL4048, MSL8048, and MSL8096 Tape Libraries User and Service Guide (AK378-96059, December 2012)

Table Of Contents
restore operations work on an entire disk, partition, or LUN. You might not be able to backup a
subset of files or restore a single file. If you can restore a single file, the restore process will be
slow.
Database backup
Performance impact: VARIABLE.
To improve performance when backing up data from a database:
Use specific backup agents for the database.
Use the latest versions of the databases.
Do not backup individual mailboxes.
Do not backup specific records or do a record-by-record backup.
Do not backup when the database is in heavy use.
Connection from the host server to the library
For the best performance, the connection from the host server to the device must have enough
bandwidth to provide enough data to keep the tape drive streaming.
NOTE: Unlike most tape technologies, an LTO tape drive can write data as fast as the server
can send it, even if the tape drive is not streaming.
Find the performance impact of your system's library connection in “Performance impact of various
parallel SCSI and FC library connections” (page 158)
or “SAS HBA speeds required for optimal performance” (page 159).
Table 38 Performance impact of various parallel SCSI and FC library connections
RecommendationsPerformance impactConnection type
Ultra 320 is an excellent transport medium,
but only has enough bandwidth for one
LTO-4 drive per bus.
GOOD. When fully used, an Ultra 320 SCSI
connection can provide enough bandwidth
for the following number of tape drives,
assuming 2:1 compression:
LTO-4: 1
Parallel SCSI: Ultra 320
NOTE: If the parallel SCSI cables are not
designed for Ultra 320 speeds or more than
a couple devices are on the parallel SCSI
bus, the bus may slow down to Ultra 160
speed.
Ultra 160 is a good transport medium, but
does not have enough bandwidth for LTO-4
POOR. An LTO-4 tape drive is unable to
sustain maximum transfer speeds with
2:1 compressible data.
Parallel SCSI: Ultra 160
tape drives. If using LTO3 or LTO-4, upgrade
to an Ultra 320 HBA, especially if you have
greater than 2:1 compressible data.
Upgrade to Ultra 320.
POOR. An Ultra 2 (80) connection is
inadequate for an LTO-3 or LTO-4 tape
drive.
Parallel SCSI: Ultra 2 (80)
Upgrade to Ultra 320.Ultra Wide and Fast Wide are inadequate
for all of the currently supported tape drives.
Parallel SCSI: Ultra Wide,
Fast Wide
Upgrade to 4 Gb or 8 Gb Fibre Channel.POOR. One gigabit fibre is inadequate for
an LTO tape drive.
Fibre Channel: 1 Gb
158 Troubleshooting