SAP uses are a lot of hard disk space, not only for the application but also for the data that it stores.
Both of which are very important and therefore we need to use a method in which we can recover data in case of disk failure. For this reason we use RAID – “Redundancy array of inexpensive disks”
The two types of RAID SAP recommends is RAID 1 and RAID 5
- RAID 1 uses two disks and is a mirror of each disk. If one disk fails, replacing it will recreate the data.
- RAID 4 uses three of more disks. It uses striping where data is written across many disks to improve speed and parity. Therefore if one disk fails, it can be replaced and the data would be recreated.
The minimum recommended structure is to have
- RAID 1 disk with the Operating System, Page file, Temporary Database, SQL Executables, SAP Executables and the transaction log.
- RAID 5 disks would only hold the database.
The recommended structure is to have a three RAID 1 and one RAID 5 setup.
- RAID 1 disk with the Operating System, Page file, Temporary Database, SQL Executables, SAP Executables and the transaction log.
- RAID 1 disk with the Temporary Database, SQL Executables and SAP Executables
- RAID 1 disk with the transaction log.
- RAID 5 disks with only the database.
Both the minimum and recommended structure should have the RAID disks partitioned as below
- C Drive: (RAID1) Operating System
- D Drive: (RAID1) Page File
- E Drive: (RAID1) Temporary Database
- F Drive: (RAID1) SQL Executable and SAP Executables
- G Drive: (RAID1) Transaction Log for the database
- H Drive: (RAID5) Database
The disks should be formatted in NTFS.
