Dell PowerConnect W-Airwave W-Airwave 7.2 Server Sizing Guide - Page 11

Disk Partitioning AWMS automatically partitions the disk subsystem upon installation. You can override these values. Table 5 and Table 6 below list the default partitioning and provides guidance for more advanced scenarios. Table 5 Default Partitions Default Partitions Size boot swap / 100 MB Twice size of RAM Rest of disk space Table 6 Advanced Partitions Default Partitions Purpose boot swap / /alternative /var/log /var/lib/pgsql /var/airwave/rrd /var/airwave-backup Boot partition Swap partition AWMS Database backup location All log from all services PostgreSQL database files Statistical flat files Nightly backup location Recommended Size 100 MB Twice size of RAM 25% of total disk space 10% of total disk space 5% of total disk space 25% of total disk space 25% of total disk space 10% of total disk space NOTE: Please ensure the disk subsystem can sustain these random write rates. Sustained sequential write rates will not help because AWMS writes are primarily random. For platforms servicing more than 2,500 devices, all "var" partitions should be located on SSDs. You may experience upgrade or installation issues when manually partitioning your disk subsystem. Symbolic links are not recommended when configuring disk subsystem because of backup and restoration issues. Storage System Tuning For RAID 10:  Ensure that all disks are configured to "One Virtual Disk".  If the RAID controller has battery-backed cache, ensure the Write Policy is configured to "Write-Back", otherwise ensure it is configured to "Write-Through". CentOS and RH Linux include four custom schedulers to handle I/O:  CFQ - Completely Fair Queuing is the default algorithm  Deadline elevator - uses a deadline algorithm to minimize I/O latency  NOOP scheduler -a simple FIFO  Anticipatory elevator - introduces a small delay before dispatching the I/O Dell PowerConnect W AirWave 7.2 | Sizing Guide CPU, BIOS, Operating Systems, and Storage | 9