User manual HP COMPAQ PROSIGNIA 720 SERVER BACKUP OF WINDOWS NT SAP R/3 SYSTEMS WITH ARCSERVE

[. . . ] WHITE PAPER December 1996 Compaq Computer Corporation CONTENTS Test Environment . . . . . . . . . . 4 ARCserve Functionality . . . . . . . . . . . . . . . . . 6 ARCserve Tape Label Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 ARCserve Engine Administrator . . . . . . . . . . . . . . . . . . . . . . 12 ARCserve RAID Engine . . . . . . . . . . . . . . . . . . . . . . . . 13 Tape Array Functionality. . . . . . . 13 Compression Tests . . . . . . . [. . . ] 20 PCI configuration The assignment of PCI controllers to PCI slots was chosen very carefully in order to get the maximum performance out of the 2 PCI buses of the Pro Liant 5000. There is an oversimplified rule which says that controllers among which a lot of I/O is expected to occur should be grouped on one PCI bus and I/O traffic across the 2 PCI busses should be avoided. There is a White Paper titled "Configuring the Compaq ProLiant 5000 Server for Peak Performance" available on the Webthat can provide you with more details . DLT Slot 8: Fast Wide SCSI-2/P Controller DLT DLT DLT Slot 6: Fast Wide SCSI-2/P Controller DLT DLT Slot 5: SMART-2/P Array Controller Slot 4: Fast Wide SCSI-2/P Controller DLT Secondary PCI Bus Slot 3: SMART-2/P Array Controller C: E: G: F: DLT Slot 7: Fast Wide SCSI -2/P Controller Primary PCI Bus Slot 2: 10/100 TX PCI UTP Controller Figure 18: Controller configuration 466A/1196 WHITE PAPER (cont. ) . 21 ARCSERVE BACKUP As already described in the ARCserve functionality section, you have different options to do a backup. With ARCserve you are able to make off-line and online backups. The off-line backup types are backup on Windows NT file system level and backup with the IMAGE option, which means that you backup complete logical drives without using the Windows NT File system. For all the following backups, Compaq used an SAP R/3 Oracle database with the SAP IDES system (which is an SAP system that already contains data for training purposes) and the SAP standard benchmark 900 client. The total database size was about 16 gigabytes. This database was located on a RAID 5 disk array that had the following layout. · · · 10 * 4, 3 GByte disks SMART-2 Controller 5 disks at SCSI channel 1, 5 disks at SCSI channel 2 Free Disks used for RAID 5 system SCSI channel 1 SCSI channel 2 gggg Backup on Windows NT File System Level In this backup mode, you get a window where you can select from single files up to all drives on your computer shown in the upper part of Figure 18. For the backup on Windows NT file system level, Compaq tested the performance of several tape array configurations. It always did a full backup of all the database files of our R/3 system. To get an impression if there is any performance difference between only one tape connected to a SCSI controller, Compaq did some test with only using 1 tape per SCSI controller. 466A/1196 WHITE PAPER (cont. ) . 22 In the tests, the following numbers were received: Number of tapes / Number of SCSIControllers 1 Tape / 1 Controller 2 Tapes / 1 Controller 2 Tapes / 2 Controllers 3 Tapes / 2 Controllers 3 Tapes / 3 Controllers 4 Tapes / 2 Controllers 4 Tapes / 4 Controllers 6 Tapes / 3 Controllers 8 Tapes / 4 Controllers Backup performance in GB/h with RAID 0 10 14 19 21 28 27 37 39 39 Backup performance in GB/h with RAID 5 not possible not possible not possible 13 19 20 27 33 38 Figure 19: Performance of backup on NT file system level From these tests, Compaq derived two results. First, the backup performance is depending on the number of tapes connected to one SCSI controller. As you can see there is a big difference if you connect only one or more tapes to a SCSI Controller. The RAID 0 backup with 4 tapes connected to 4 controllers is about 10 GB/h faster as the 4 tapes connected to 2 controllers. Never connect more than 2 DLT drives to 1 SCSI controller because of performance reasons. Second, the performance of a RAID 5 tape configuration is worse than that of a RAID 0 configuration. The worse performance of the RAID 5 configuration is caused by the fact that the parity information needed for a restore with one tape missing has to be calculated and then written on the tape. That is why you only need 2 tapes / 2 controllers with RAID 0 to get the same performance as for 3 tapes / 3 controllers with RAID5. Backup Using the Image Option The ARCserve Image Option for Windows NT allows the backup and restore of local hard drives in the image mode. This mechanism bypasses the Windows NT file system. [. . . ] 29 f:\oracle\JM2\sapdata2\btabi_2\btabi. data2 1098752 . 9 f:\oracle\jm2\sapdata2\clud_1\clud. data1 245760 . 12 f:\oracle\jm2\sapdata3\clui_1\clui. data1 33792 . 5 f:\oracle\jm2\sapdata1\ddicd_1\ddicd. data1 61440 . [. . . ]