HP StorageWorks 1/8, Руководство пользователя и сервисное руководство, Страница: 124 / 204

are concerned about viruses and backup performance, perform a virus scan before starting the
backup, and shut down the anti-virus software while the backup is running.
Backup server
The backup server must have enough RAM and processor power to transfer the files from the disk to
the tape drive. See
Table 30 for the minimum RAM and CPU speed needed for each tape drive. In
some cases, a multi-processor server may be required.
NOTE:
Processor speed numbers as based on Intel x86 type processors. Use the equivalent on a RISC or
other type of processor.
Table 30 Backup server requirements
Processor power/drive Minimum RAM/drive Tape drive
1 GHz 512 MB LTO-2
2 GHz 1 GB LTO-3, LTO-4
4 GHz 2 GB
LTO-5
In addition to having enough RAM and processing power, ensure that the PCIe bus is at least 64 bit,
has a speed of 66 MHz or better, and is not overloaded by too many high-bandwidth cards. PCIe is
preferred.
Backup type
Each type of backup has its own impact on performance, depending on how well it can keep data
streaming to the tape drive.
File-by-file with a full-featured backup application
Performance impact: VARIABLE .
File-by-file backup with a full-featured backup application can be fast enough if the average file size
is at least 64 k and there are not too many fragmented files. Full-featured backup applications also
offer the best speeds for single file restores and allows for backing up only specific data. Check the
compatibility matrix on the EBS website for a list of full-featured backup applications supported on
your operating system for your Tape Autoloader: http://www.hp.com/go/ebs.
If the average file size is less than 64 k or if the file system is very fragmented, file-by-file backup will
have poor performance. If the file system has a lot of fragmentation, use a de-fragmentation utility to
make the files contiguous again. If the average file size is less than 64 k, HP recommends that you
use a sequential/image backup that backups up the hard drive or LUN image instead of the individual
files. The drawback with sequential/image backups is that they may only be able to restore the entire
disk image and not individual files. If they can restore individual files, the restore operation will be
very slow.
Troubleshooting 124