Disk Space

Predicting disk sizing requirements for QAD BI is complex. See Key IO Subsystem Sizing Notes below and Reference: Estimation of Initial Database Size for details. Follow these guidelines.

1. Minimum - A minimum of 500-GB disk space is recommended, but see points 5 and 6.

2. Ideal - Ideally 1 TB of disk space is recommended, but see points 5 and 6.

3. Allowance for database growth - To allow for BI database growth, 2-3 times the size of the original BI database is recommended. See Allowance for Future Database Growth for the exact details.

4. Allowance for disk expansion – If appropriate and to allow for future project growth, it is recommended that you allow for disk expansion capabilities in the SAN/NAS device.

5. Estimation - Reference: Estimation of Initial Database Size provides an approximate method of estimating the initial BI database size from source ERP tables. This method can be used along with point 3 above. To provide an estimate of the initial disk space requirements for a new implementation, multiply “estimated”database size by a factor of 2-3 to allow for growth.

6. If the estimate from point 5 returns over 500 GB or over 1 TB of disk space requirements, then obviously size accordingly.

SAN/NAS?

It is preferable to use external disk arrays or SAN/NAS devices where possible. Configure internal disk drives to hold the operating system only.

RAID Level

RAID 5 or RAID 10 preferred.

Physical Disks

Fastest disks available: 15 k rpm SAS (or fiber channel) disks preferred.

Note 1: Due to the larger IO demands of BI systems, a minimum of six disks is recommended. Double the number of disks when using mirroring.

Note 2: More disks are preferred, as this significantly helps performance and IO rates.

IO Controller

Ensure that IO controller throughput does not limit transfer rates to/from disks. Where possible spread the IO across as many controllers as possible.