## Contents

## What type of RAID’s can be created with ZFS?

### stripe

### mirror

### n-way mirror

### raidz or raidz1

### raidz2

## Size and Speed of the different RAID-types

**Info**

These information I’ve got from: WHEN TO (AND NOT TO) USE RAID-Z

S_{t} |
= | Total size of the pool |

n |
= | Number of disks in the pool |

S_{disk} |
= | Size of one Disk |

v_{f} |
= | Speed Factor (1 = Same speed as a single Disk) |

v_{disk} |
= | Speed of the disk is Blocks/Seconds |

x |
= | Number of Stripes |

### Stripe

You stripe all disks together:

S_{t} = n * S_{disk}

v_{f} = n

**Example:** Assume we have 100 Disks 50GB each which can write 200 Blocks/seconds:

Total RAID size...: 5000 GB = 100 Disk * 50 GB/Disk Speed factor......: 100 = 100

### Mirror

You mirror two disks or two stripe-sets:

S_{t} = (n / 2 ) * S_{disk}

v_{f} = n / 2

**Example:** Assume we have 100 Disks, 50GB each which can write 200 Blocks/seconds. We make the mirror over a stripesets of 50 Disk each:

Total RAID size...: 2500 GB = ( 100 Disk / 2 ) * 50 GB/Disk Speed factor......: 50 = 100 Disks / 2

### raidz

You stripe some raidz’s:

S_{t} = (( n / x ) – 1 ) * S_{disk} * x

v_{f} = x

**Example:** Assume we have 100 Disks 50GB each which can write 200 Blocks/seconds and we stripe 5 raidz’s together:

Total RAID size...: 4750 GB = (( 100 Disk / 5 Stripes ) - 1 ) * 50 GB/Disk * 5 Stripes Speed factor......: 5 = 5