Disk Partitioning; Storage System Tuning - Dell PowerConnect W-Airwave Manual

Disk Partitioning

AWMS automatically partitions the disk subsystem upon installation. You can override these values.
Table 6 below list the default partitioning and provides guidance for more advanced scenarios.
Table 5
Default Partitions
Default Partitions
boot
swap
/
Table 6
Advanced Partitions
Default Partitions
boot
swap
/
/alternative
/var/log
/var/lib/pgsql
/var/airwave/rrd
/var/airwave-backup
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
Size
100 MB
Twice size of RAM
Rest of disk space
Purpose
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
CPU, BIOS, Operating Systems, and Storage | 9
Table 5 and