Xhost Backup Implementation

Introduction

The operation to backup the Xhost NT computer community will use Computer Associates ArcserveIT version 6.61 and will initially loaded on XHOSTSQL. It will be the Advance Edition, therefore allowing backup of other workstations and servers across the LAN. A copy of the NT Open File Backup agent will also be loaded on XHOSTSQL allowing the backup of files which are currently open (especially important for the backup of the SQL databases, although for the future the CA Backup Agent for SQL may be utilised to improve the SQL backup functionality). The Open File agent is an unlimited copy, so may be placed on the other workstations and servers, allowing open files to be backed up on the full NT computer community. In order to speed up the backup process and to take advantage of the open file agent the CA ArcserveIT Client Agent for Windows NT must be installed on all other computers to be included in the backup schedule.

LAN Diagram

Hardware Configuration

The server XHOSTSQL is a Compaq Proliant 850R with an on board wide ultra SCSI. This is connected externally via a wide ultra SCSI cable to a rack mounted DLT tape array. The tape array contains 4 x 15/30 DLT3000, which can be presented externally as 4 individual drives, or a single chain of 4 drives. Currently it is 4 single drives labelled A-D with Tape A on the left as one faces the unit. Therefore XHOSTSQL is writing only to Tape A.

Software Configuration

The main program ArcserverIT manager is installed and runs on XHOSTSQL’s C:drive in c:\arcserve, the open file agent is also on the C: drive in a directory called C:\ofawin. To enable backup of open files on remote workstations and servers requires ofawin to be run on XHOSTSQL and a remote install launched to the remote computer. Before doing this the whole of the c:\ca_lic must be copied from XHOSTSQL to the remote computer. Finally the NT client agent must be installed on the remote computer using the Arcserve CD. The remote computer can now be added to the backup schedule by selecting it in ArcserveIT manager program from the list of clients

Backup Scheduling and Tape Rotation

The plan is to backup all computers at least daily and at a quiet period, therefore it will be scheduled to start at 3a.m. – a full backup of all listed servers will be taken on Sunday and differential only backups Monday-Saturday (i.e. only those files added or amended since the last full backup). In order to maintain a full archived record of data the full GFS (grandfather, father, son) option is taken which means a tape pool of 23 tapes will be maintained:-

6 Daily tapes to be used Monday, Tuesday, Wednesday, Thursday, Friday, Saturday

5 Weekly tapes to be used Sunday Week1, Sunday Week2, Sunday Week3, Sunday Week 4, Sunday Week 5

12 Monthly tapes to be used Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec

Using Arcserveit Manager the backup log will need to be checked and printed off daily and any significant errors reported. The tape then needs to be changed for the next day’s backup, and the removed tape securely stored and the logs filed. The monthly tapes are to be handed over for secure storage offsite. Once the schedule has been run for a year the appropriate monthly tape will need to be recalled from offsite storage and reformatted prior to reuse.

Tape Maintenance

The expected life of daily tapes will be 1 year but the may occasionally require to be erased and re-tensioned using the tape utilities. Weekly tapes should last considerably longer but will be replaced every 2 years. To lessen tape damage and backup failures the tape heads need regular cleaning using the special cleaning tape – this tape is inserted in the drive bay instead of a normal tape and the cleaning cycle commences. A cleaning tape will last for 20 tape cleans and should have one of it’s “lives” crossed out after each usage. Ideally this cleaning is carried out at least weekly and preferably on a Saturday i.e. prior to inserting the Sunday weekly full backup tape.

John Foster

20 Mar. 00