Connection From The Host Server To The Disks - HP BL536A User's & Service Manual

Table 28 Performance impact of various file systems
File system
Disk array
Server or workstation
with RAID
Server or workstation
with a single disk
(spindle)

Connection from the host server to the disks

The connection between the host server and the disks determines how much data can be transferred
from the disks to the host computer at a time. A connection with insufficient bandwidth cannot
provide enough data for the tape drives to write at full speed. Find the performance impact of your
system's disk connection in
Performance impact
GOOD. Disk arrays typically provide
excellent access to data. They usually
include many disks, which improves
bandwidth.
VARIABLE. RAID uses a group of disks
to improve performance, and in the case
of RAID 5, provides some parity
protection in case one of the drives fail.
POOR. A single disk cannot retrieve or
write data fast enough for any of the
supported tape drives.
Table 29 (page 98).
Recommendations
None.
To achieve optimal performance, your array must
support the following transfer rate:
LTO-2 HH: 48 MB/s
LTO-3 HH: 120 MB/s
LTO-4 HH: 160 MB/s
LTO-5: 280 MB/s
Also, make sure that the server or workstation is
used as little as possible during the backup, and
close down programs such as virus scanners,
which check each file that is opened.
Upgrade to a disk array or RAID 5 with the
minimum number of disks needed for your tape
drives, or use concurrency or multithreading in the
backup software to pull from more than one disk
at a time. The drawback with concurrency or
multithreading is that it slows the restore operation.
Also, make sure that the server or workstation is
used as little as possible during the backup, and
close down programs such as virus scanners,
which check each file that is opened.
Performance problems 97