Backup Solutions: A Practical Example
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Novell Worldwide Support
01 Jan 1998
The following example of a practical backup solution comes from the administrator of an 80-server Novell network which included 68 IntranetWare servers, 12 NetWare 3.12 servers, 3 Sun Workstations, and 2 Hewlett-Packard Unix servers. The backup solutions the company was using were disparate across platforms, which made it difficult to maintain backup on all platforms. The NetWare servers were backed up using the SBACKUP utility with 8mm tape drives for the IntranetWare servers and Arcserve 4.0 (also with 8mm tape drives) for the NetWare 3.12 servers. A Legato backup solution with 4mm tape drives was used for the Hewlett-Packard servers. The Sun Workstations were not backed up at all.
This backup solution required daily tape changes, since they were performing full backups to ensure data integrity. The tape changing activity needed to be administered from an HP workstation as well as on both servers that were running SBACKUP and Arcserve 4.0. The backup method was time consuming because of the daily tape changes, which meant physically visiting the NetWare servers and monitoring the backups to ensure they ran throughout the night.
The challenge was to put together a solution that could back up all of the disparate systems between midnight and 7:00 a.m. every night. The company needed to perform reliable backups, with the ability to perform restores quickly when necessary, without having to search for the correct tapes. Also, the NetWare servers needed to be completely reliable and not have problems during or after the backups.
At the beginning, it was determined that backing up client workstations along with the servers was beyond the scope of this project. Those groups who needed their workstations backed up were required to install their own backup server for these workstations in their area.
With these requirements in mind, the company began testing a number of different backup solutions for both NetWare and Unix. After reviewing several different software packages, they wanted to try Arcserve's new 6.1 version, as it offered a single solution that could be used across all operating system platforms, and allowed a backup strategy to be tailored to specific needs.
To assure reliable backups and server performance, they decided to use separate NetWare file servers for the backup servers. Since the time frame for performing backups was so short, they decided to install one backup server per network segment. Since they had five separate networks, they purchased five new servers and installed IntranetWare and Arcserve 6.1 on all of the servers. One backup server was placed on each network segment.
Since each of the backup servers was responsible for backing up approximately 17 servers (including IntranetWare, NetWare 3.12, Hewlett-Packard Unix and Sun Workstations), the project team did not feel that 8mm drives provided the speed necessary to complete the task in the time allotted (seven hours). After testing several different tape drives, they determined only DLT drives would provide the necessary speed to perform the backup, as well as the reliability needed for this scenario. After performing speed tests, they found that they only needed five DLT drives per backup server, since Arcserve could write data to all five of the drives at the same time.
Figure 1 shows the configuration of the network, including the servers. Figure 1: The backup configuration consists of five backup servers.
Network one contained 15 IntranetWare file servers and two Sun workstations. They first installed the Arcserve Sun agent on the workstations and the Arcserve push agent on the IntranetWare servers. They then designated DLT1 and DLT2 to back up three IntranetWare servers each, DLT3 to back up three NetWare servers, with DLT4 and DLT5 responsible for three IntranetWare servers and one Sun workstation each. To ensure backup reliability and speed with full disaster recovery, they created a custom backup scheme.
On Friday and Saturday, they perform a full backup of all the data on all of the file servers. On Monday through Thursday, they use a differential backup to copy only the data that has changed since the last full backup. Since data didn't change much on a daily basis, they were able to fit all of the differential backups on the same tape.
The beauty of this backup solution was its ease of administration. They were able to send the Saturday full backup to a data storage location, and only had to change tapes on Mondays, Fridays, and Saturdays. They were also able to check and see if all of the backups had worked, failed, or had errors during the backup procedure by logging in, mapping drives to all five of the backup servers, and using Arcserve's quick status function.
With this new backup strategy, the backup team saved two to three hours per day, and the reliability of the backups increased to 100%. By using a cross-platform solution to back up all servers, the ease of administration was greatly enhanced.
* Originally published in Novell AppNotes
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