Let’s have a look at drive reliability and performance.

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Reliability and Performance
In this video I will look at some of the ways we can check the reliability of our storage devices. For example, using S.M.A.R.T. to measure reliability and tools like CrystalDiskMark to measure performance.

Let’s have a look at how to read this information and use it.

S.M.A.R.T.
Many drives have built-in reporting called S.M.A.R.T., short for Self-Monitoring Analysis and Reporting Technology. S.M.A.R.T. reports various indicators of drive reliability and other information. It can also anticipate hardware failures. However, before you start using S.M.A.R.T. there are some things to understand.

S.M.A.R.T. reporting is vendor specific. Unfortunately, there are no standards. Thus, it is implemented differently on different devices and some implementations are better than others. You will generally find that S.M.A.R.T. is always implemented on Solid-State-Drives, but not all hard disks support it.

CrystalDiskInfo [ Ссылка ]
I will now have a look at the software CrystalDiskInfo. This freely available software reads S.M.A.R.T. and other information for storage devices. Interpreting S.M.A.R.T can be challenging as each manufacturer may provide S.M.A.R.T. information differently.

The storage device I am showing is a Solid-State-Drive. The software processes the information it finds and attempts to present it in a friendly way at the top. The S.M.A.R.T. data is at the bottom of the screen.

In the case of Solid-State-Drives, the main factor affecting life expectancy is how many writes have been performed. Once cells in a Solid-State-Drive are worn out, it has some spares to replace the failed cells. You can see in the S.M.A.R.T. data a value called “Available Spare”. This value is 6 4 in hexadecimal and 100 in decimal.

If the number of spare cells available starts going down, you should consider replacing the storage device.

In the S.M.A.R.T. data, you can also see the amount of data that has been written to the Solid-State-Drive. The software provides a friendly version of this number at the top. In this case, almost 50,000 Gigabytes have been written to this drive. This storage device has a lifespan of some 200 Terabytes of data, so there is still some life left.

I will now change to a hard disk. Hard disks suffer from wear and tear but writing a lot of data to the drive does not affect it the same way. However, sectors on the hard disk can still go bad. When this occurs, the hard disk drive swaps the bad sector with some spares reserved at the end of the drive.

You will notice the value, “Reallocated Sector Count” has a current value of 200. So, this would tend to suggest that there have been 200 sectors reallocated. However, this is incorrect. The raw value is zero, which would tend to indicate no sectors have been reallocated. One value suggests the hard disk needs to be replaced, while the other indicates it is fine. This goes to show how difficult it can be to understand and interpret S.M.A.R.T. data. To understand what the S.M.A.R.T. data is telling us, I will have a look at a tool from the manufacturer.

Manufacture’s Tools
Each storage manufacturer has their own tools. I will have a look at a dashboard provided by Western Digital. These tools will often only work with storage devices from that manufacturer. You will find these tools often provide additional information and options that are not available in non-specific manufacturer tools.

The first screen provides general information including health information. If there is a serious problem with your storage device, it should be shown here.

I will now select a hard disk from the pull-down menu. You will notice that some of the information displayed changes slightly, since the health of these storage devices is measured differently.

I will now select the tab “Tools”. The manufacturer will generally provide some additional tools to test the storage device. In this case, I will select the option to open the S.M.A.R.T. data.

You will notice that only five S.M.A.R.T. settings are shown. Some tools will show more information than others. Even tools from the manufacturer may not show all the available options but will generally show some options not available in other tools. You will notice that the option, “Reassigned Sector Count” is displayed here.

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References
“The Official CompTIA A+ Core Study Guide (Exam 220-1101)” pages 103 to 105

Credits
Trainer: Austin Mason [ Ссылка ]
Voice Talent: HP Lewis [ Ссылка ]
Quality Assurance: Brett Batson [ Ссылка ]

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