Storage tools for planning arrays before buying drives

Plan a storage array or backup before you buy drives: usable space, how many drives can fail, rebuild risk, growth, and backup size. Enter the drives and layout you plan to run. Not sure where to start? Use the storage layout advisor, or find your question in the table below the tools.

Tools

3-2-1 backup calculator

Size local and off-site backup storage from your data and retention.

RAID calculator

See usable space and how many drives can fail for any RAID level, even with mixed drives.

ZFS capacity calculator

Estimate writable space for a pool of mirror and RAIDZ vdevs.

ZFS padding calculator

See how much space one block takes on RAIDZ, with parity and padding.

RAIDZ expansion planner

See the space you gain by adding disks to a RAIDZ vdev.

SHR calculator

Estimate Synology SHR-1 or SHR-2 space from mixed drive sizes.

Unraid calculator

See Unraid array space and whether a new drive needs bigger parity.

SnapRAID and mergerfs planner

Build a snapraid.conf and mergerfs fstab line from your disks.

Drive reliability explorer

Look up and compare hard drive failure rates by model.

RAID rebuild calculator

Estimate rebuild time and read-error exposure after a drive fails.

Ceph capacity calculator

See usable Ceph space and what happens when the largest host or rack fails.

Storage growth planner

See when your data outgrows your storage and what it costs to run.

Storage layout advisor

Compare RAID and ZFS layouts for your drives and failure target.

Restic retention simulator

See which restic snapshots a keep-daily, weekly, and monthly policy keeps.

NFS firewall rules

Get the ports and firewall rules NFSv3 or NFSv4 needs on a server or client.

Which storage tool do I need?

Find the question you're asking.

Your questionTool to use
Which layout should I build with my drives?Storage layout advisor
How much space will this RAID level give me?RAID calculator
How much space will my ZFS pool have?ZFS capacity calculator
Why does RAIDZ use more space than I expected?ZFS padding calculator
What do I gain by adding a disk to a RAIDZ vdev?RAIDZ expansion planner
How much space will my Synology, Unraid, or Ceph setup have?SHR calculator, Unraid calculator, Ceph capacity calculator
How do I set up SnapRAID with mergerfs?SnapRAID and mergerfs planner
Which drive models fail least?Drive reliability explorer
How long will a rebuild take, and how risky is it?RAID rebuild calculator
When will I run out of space?Storage growth planner
How much backup storage do I need?3-2-1 backup calculator
Which snapshots will my restic policy keep?Restic retention simulator
Which ports does an NFS share need open?NFS firewall rules