# DiskScan — The way to answer if a disk is good or not

Diskscan is intended to provide the information needed to decide if a disk is good or not, be it an HDD or an SSD it is likely to be holding important data and if you have a suspicion that it is failing it is also important to know how bad is it down the road. Diskscan will only perform reads in its disk surface scan so it is not destructive in any way and it will report on all the key metrics needed to decide if the disk is good or not, currently that includes reporting all the errors that were encountered, a latency histogram over the entire surface and a graph of the min/max/median latency over the disk surface.

# How to install

## Prerequisites

• You’ll need C compiler, gcc is assumed, you can set CC to change it
• To build the documentation you need the python-markdown and python-beautifulsoup packages.

## Install

Fetch the latest release from diskscan releases

Untar and Run:

DESTDIR=/ PREFIX=/usr/local ./do all install


# Usage

## Run

As shown in the screenshot all you need to do is give diskscan the device name to test, it can be either /dev/sdx or /dev/sg4 both enable the use of raw SCSI commands to get the best test results for both accuracy of timing and accuracy of error reporting.

./diskscan /dev/sdx


## Understanding the results

TODO


## Is my disk failing or marginal?

TODO