What are you missing? Long-term data retention and SSD/HDD stories < Special Feature < Main article

“Forgetfulness is also God’s consideration,” says the grim reaper from the drama Goblin, serving tea that can help you forget the memories of this world. Like this saying, forgetting a fact is not necessarily bad by human standards. Those shameful memories that give you goosebumps just thinking about them are slowly forgotten as if they were nothing as time goes by.

But what if you can’t find happiness in oblivion? Then don’t forget Especially if it’s not a person. For example, the reason for taking pictures is to leave evidence for loss. At the same time as proving the truth of the moment, it can be used as an auxiliary means of memory. But what if those photos are damaged? A photograph that cannot be associated with memory has no meaning. Data is like this. If it is not related to the ‘right to be forgotten’, there is virtually no net function when data is compromised. So, data retention is very important.

There is a passage like this in the Sutra of Great Companion Nirvana, which was recorded about Shakyamuni’s nirvana. “Everything that is born, exists, and is formed is a law that is bound to break, but it is impossible that it does not disappear,” Sakyamuni said, “nothing is permanent in this world.”

Data is also like this. No data can be preserved forever without effort. Of course, there may be media that are more stable for long-term storage, but it should be taken into account that storage media has a lifespan. This is the reason why magnetic tape storage media are still used even at the present time when SSD and HDD are popular. This is because it is just an expensive, complicated and slow storage device from the point of view of general users, but it has a particularly long lifespan among storage media in terms of data backup and preservation.

Let’s get back to HDDs and SSDs. Which storage device is faster, HDD or SSD? Simple. It’s an SSD. Then, which of the two storage media is the cheapest compared to the capacity? This is simple too. It is HDD. For a little more than the cost of a high-end PCIe 4.0 1TB SSD, you can buy a consumer 8TB HDD.

It’s the last one. Which storage device is better, HDD or SSD, for long-term data retention? Let’s take a simple example to help you understand. Here, a couple from South Korea are trying to store a time capsule in a warehouse. The couple put a storage device containing their precious memories in a time capsule. Which storage device would you recommend for this couple? The reporter seems to choose HDD.

I was asked to install an older version of Windows. It reminded me of the Windows installation USB I made a long time ago. It’s a well-used USB. However, when I go through the installation process, it says that the installation failed. It obviously worked well in the past, so why did it fail?

This failure case is due to the characteristics of flash memory. Flash memory retains its data even when the power is turned off. However, that is not permanent. Flash memory stores data as a small charge. What happens to that charge after a period of time without power being supplied? You can get out slowly. The cell whose charge is drained in this way can change its data from 1 to 0. Then data will be lost. Therefore, flash memory left unattended for a long time may lose data. Power must be supplied to keep the data stable.

The same goes for SSDs. Data is stored on the SSD, and of course the data remains when the power is turned off. In a state where power is always supplied, SSD is a very good storage device. But what if you leave it turned off for a long time?

SSDs are greatly affected by temperature when power is not supplied. The data was included in the JEDEC SSD specification explanation presentation released in 2015.

Let’s say you have a consumer SSD that’s been used 8 hours a day at around 40 degrees. If this SSD is stored in an environment of 25 degrees after the power is turned off, it is expected to be able to preserve data for 105 weeks (about 2 years). But what if it is stored in a 30 degree environment? The data retention period is expected to be 52 weeks (approximately 1 year). cut in half For reference, if stored in a 55 degree environment, the data retention period is expected to be approximately 2 weeks.

In other words, when considering SSDs for data retention purposes, temperature cannot be ignored. In addition, the write life of the SSD must be taken into account. The inability to hold charge in the floating gate can lead to poor data retention and eventually to failure. So, if you use an SSD for the purpose of preserving data, there are a lot of things to worry about.

There is one more. This is when the SSD storing the data fails. If the firmware is damaged, you can try various things, but if the NAND flash is damaged, data cannot be recovered.

In terms of data retention, HDDs are definitely better than SSDs. The reason can be easily divided into two parts. First, HDDs, which are magnetic drives, are more reliable for long-term storage of data than flash memory drives, SSDs, when power is not applied. Second, even if the HDD fails, data recovery attempts can be made. The probability of saving data is much higher than SSD.

The countermeasure is different when connecting the storage device to a PC after long-term storage. If the data on the SSD is corrupted, you can see that it is not recognized or that the data inside is altered. At this time, there is nothing you can do.

However, the HDD gives many hints to detect the symptoms of failure. No power, no vibration, or a scratching sound from inside. If you see such symptoms, you can prepare quickly. In this case, if you quickly cut off the power of the hard disk and send it to a recovery company, the chances of saving the data are very high.

Then, which hard disk should be selected for data preservation? The selection criterion can be considered as simple as two.

1. Do you carry it often?

2. Do you provide data recovery services?

For general consumers, the storage media specialized for data storage is an external hard drive. It can contain a large amount of data in a small size. For example, products such as the Seagate Ultra Touch HDD (Seagate Ultra Touch) are divided into 2TB, 4TB, and 5TB, and the weight of the 5TB family is about 267g at most. It is not that difficult to carry.

If you don’t carry it often, you should choose a 3.5-inch hard disk. As of May 26, 2023, an 8TB hard disk can be purchased for around 170,000 won. Next, if you need a hard disk with a large capacity, a NAS HDD such as the recently released 22TB Seagate IronWolf Pro is a good option.

Second, it’s a good idea to check whether a data recovery service is offered. This can be thought of as being insured. If you use a hard disk that does not provide data recovery service and lose data, the recovery cost is quite high. In many cases, recovery is even abandoned because of cost.

However, if a data recovery service is provided by default, you can use it without much worry. If you can recover data from a failed storage device for free, this is a great option for data retention.

Seagate ‘Rescue Recovery Service’ is like this. For example, if data is lost while preserving data in an external hard drive, the rescue data recovery service can restore the data of the damaged storage device. The service is provided free of charge for 3 years after purchase. The data recovery success rate averages over 90%. When requesting a recovery service, an ultra touch with the same capacity is provided, and the recovered data is delivered to an external hard drive, USB memory, or cloud storage, depending on the capacity.

HDDs can now store up to 22TB of capacity with a single drive. It is developing in a different direction than SSD. So, it is no longer possible to simply see that SSDs replace HDDs. At this point, it is more appropriate to view it as a symbiotic relationship. It can be seen that the OS drive and program execution are in charge of the SSD, and the data preservation is in charge of the HDD. As the size of the data that the world creates is getting bigger and bigger, it is expected that the demand for HDD will be steady in the future.