6.0.0-git
2019-11-13

Diff for HardwareRequirements between 1 and 2

++Horde Hardware Requirements

You can get a general sense for the hardware requirements of Horde by looking at the ((Deployments)) page.

Here are some general guidelines for determining the number of hard disk drives required for a given I/O load.  This information is probably more useful for email server administrators than Horde administrators because Horde is generally not I/O bound.

+++Determining disk drives if you know the IOPS required

If you can make an estimate of how many I/O's Per Second (IOPS) you need you can determine how many disks you'll need as RAID10 and how many disks you'll need as RAID5.

Generally, a single disk drive can do this many IOPS per disk:

> 15k rpm: 180-210 IOPS
> 10k rpm: 130-150 IOPS
> 7200 rpm: 80-100 IOPS
> 5400 rpm: 50-80 IOPS

In a mirrored configuration:

> Disk IOPS = Read IOPS + (2 * Write IOPS)

In a parity (RAID5) configuration:

> Disk IOPS = Read IOPS + (4 * Write IOPS)

+++Example calculations

Now let's look at an example.  If you estimate that you need to support 40 Read IOPS (40 reads/sec) and 80 Write IOPS (80 writes/sec).

If you want to use a mirrored configuration of drives:

> Disk IOPS = Read IOPS + (2 * Write IOPS) = 40r/s + (2 * 80w/s) = 200 Disk IOPS
> 
> Using 7200 rpm drives, you need: 200 / 50 = 4 disk drives
> Using 10k rpm drives, you need: 200 / 130 = 2 disk drives (always round up)

If you want to use a parity (RAID5) conigurationconfiguration of drives:

> Disk IOPS = Read IOPS + (4 * Write IOPS) = 40r/s + (4 * 80w/s) = 360 Disk IOPS
> 
> Using 7200 rpm drives, you need: 360 / 50 = 8 disk drives (always round up)
> Using 10k rpm drives, you need: 360 / 130 = 3 disk drives