Are SSDs good for long term backup?

SSDs, or solid-state drives, are a type of computer storage device that uses flash memory rather than spinning platters like traditional hard disk drives (HDDs). Some key benefits of SSDs over HDDs include:

  • Faster read/write speeds – SSDs can access data much more quickly than HDDs because they don’t rely on physical moving parts. This makes them better for tasks like booting your computer or launching applications. [1]
  • Increased durability – SSDs have no moving parts, making them more durable and shock-resistant than HDDs with spinning platters and read/write heads. SSDs can better withstand drops, vibration, etc. [2]
  • Lower power consumption – SSDs are more energy efficient than HDDs, using less power during operation and extending laptop battery life.
  • Compact size – SSDs come in much smaller physical packages than HDDs since they don’t require bulky spinning disks/heads.

For these reasons, SSDs are increasingly being used in computers and laptops as faster and more reliable storage options compared to traditional HDDs.

SSD Lifespan

SSDs have a finite lifespan and will eventually fail due to the way they store data. Unlike traditional HDDs that store data on magnetic spinning platters, SSDs store data in NAND flash memory cells. Each cell can only withstand a limited number of erase/write cycles before it becomes unusable, usually around 3,000-10,000 cycles (though some newer drives can last up to 100,000).

This means every time new data is written, it uses up some of the available write cycles. Once all the cycles are used up, portions of the SSD will become read-only and it will eventually fail entirely. The total amount of data written over the lifetime of the drive, known as total bytes written (TBW), determines when this will occur [1]. Heavy workloads with lots of writes will use up the available cycles faster.

So while SSDs don’t have moving parts that can mechanically fail like HDDs, their NAND flash memory does degrade over time. This makes them unsuitable for very long term archival storage spanning 5-10+ years. The finite write endurance must be considered when using SSDs for backup.

Data Retention

One concern with using SSDs for long-term backup is the potential for data retention issues over time, especially if the drive is not powered on regularly. Unlike traditional HDDs, SSDs store data in NAND flash memory cells that can slowly discharge over time if left unpowered.

According to tests by AnandTech, the threshold for data retention issues on consumer SSDs is typically around 1-2 years if stored at room temperature [1]. However, enterprise SSDs designed for archival use can retain data for much longer, with some rated for 10 years or more. The retention period also improves significantly if the SSD is stored at lower temperatures.

To avoid data loss, it’s recommended to power on SSDs used for long-term backup at least every 6-12 months to allow the drive to refresh the stored data. This resets the retention period. Otherwise, over longer periods of years, corruption can occur as cells discharge, especially for files that rarely get accessed.

Failure Modes

SSDs and HDDs have different failure modes. HDDs typically provide warning signs before complete failure, such as bad sectors and performance issues. This allows for data recovery if a backup exists. SSDs, in contrast, can fail suddenly with little or no warning (source).

Common SSD failure modes include write failures, read errors, and total unresponsiveness. These failures can happen abruptly at any point during the SSD’s lifetime. SSDs have complex controller electronics that can simply stop working correctly. Data recovery from a failed SSD is very difficult, if not impossible, unlike HDDs which often allow data recovery in failure scenarios.

In summary, HDDs tend to degrade slowly over time and show signs before total failure, allowing for data recovery. SSDs, however, can experience sudden catastrophic failures without warning, making data recovery extremely difficult.

Backup Medium

When comparing SSDs to HDDs and magnetic tape as backup mediums, there are a few key factors to consider – lifespan, reliability, and cost.

SSDs tend to have a shorter lifespan than HDDs or tape. Most SSDs last around 5-10 years under normal use before failures start occurring, whereas HDDs can last 10-15 years, and magnetic tape can last up to 30 years if stored properly (https://www.altaro.com/backup-dr/tape-storage-vs-disk-storage/). However, SSDs do have faster access times for data recovery.

In terms of reliability, tape has been proven to be very reliable for long-term backup storage. The linear magnetic format is less prone to corruption over time compared to the mechanical components in HDDs. SSDs can suffer from data retention issues after prolonged periods without power (https://www.techtarget.com/searchdatabackup/tip/Storage-media-showdown-The-benefits-of-tape-vs-disk-backup).

Finally, tape is the most cost-effective backup medium for long-term archival storage. HDDs are cheaper than SSDs, but the cost per terabyte for tape drives and media is much lower than disk storage, especially at larger scales. The trade-off is slower access times compared to disk (https://www.minitool.com/backup-tips/tape-vs-disk-storage.html).

Backup Strategy

When backing up to SSDs, it’s important to follow best practices to ensure your data is protected. Some key recommendations include:

Perform frequent backups – Back up your SSD on a regular basis, such as daily or weekly. More frequent backups reduce the risk of data loss if the drive fails.

Maintain multiple copies – Keep at least three copies of your backup, such as the original data and two backup copies. This provides redundancy in case one copy becomes corrupted or lost.

Use offsite or cloud storage – Store one copy of your backup offsite or in the cloud. This protects against data loss due to events like fires, floods or theft.

Test your backups – Periodically restore files from your SSD backup to ensure the process is working properly. This verifies you can successfully recover data when needed.

Follow the 3-2-1 rule – Maintain three copies of your data, using two different media types, with one copy stored offsite. This covers the key principles of backup best practices.

With the right backup strategy, SSDs can provide reliable storage for protecting important data over the long term. Following best practices is key to get the most out of SSD backup.

Archival Storage

SSDs may not be the most suitable option for long-term archival storage compared to HDDs and tape drives. SSDs have a limited lifespan and gradual degradation of data retention over time, whereas magnetic HDDs and tape can reliably store data for decades if stored properly. According to a Reddit discussion on r/DataHoarder, SSDs realistically only last 3-5 years for archival storage due to wear from writing/rewriting data. Tape drives designed for archival use offer much longer 30+ year lifespans. HDDs also outlive SSDs with 7-10 years of archival usage commonly reported. For true long-term archival needs, tape or HDDs are better options than SSDs currently. However, SSDs may still be suitable for shorter term backup/archival needs of 3-5 years.

Cost Considerations

When comparing the costs of HDDs and SSDs for backup storage, it’s important to look at the cost per gigabyte (GB) over time. Initially, SSDs were significantly more expensive than HDDs on a per GB basis. However, over the past decade, SSD costs have declined rapidly while HDD costs have remained relatively flat.

According to one analysis, in 2007 the average cost per GB for a consumer HDD was around $0.50, compared to $7.37 for an SSD. By 2019, HDD costs had only declined to $0.03 per GB while SSDs had dropped to $0.10 per GB. So although SSDs are still more expensive for an equivalent amount of storage, the cost premium has shrunk considerably.

Industry projections expect this trend to continue, with SSD $/GB declining up to 30% per year while HDD costs decline about 10% annually. As production scales up, SSD costs should continue becoming more competitive with HDDs in terms of upfront purchase price.

Source: Overview of the Pt and Ru Demand during Recent HDD Technology Transitions

Recommendations

SSDs can serve as a reliable backup medium in certain use cases. Their fast transfer speeds, compact size, and durability make them well-suited for backing up important files you access frequently.

For short-term backups or backups of your operating system and applications, an SSD is a great option. The speed of copying files on and off the drive is far faster than a traditional hard disk drive. This makes SSDs convenient for quick backups before major system changes or regular file backups 1.

However, for archival or long-term backups, an SSD may not be the best choice. SSDs have a finite number of write cycles before failure, whereas magnetic hard drives can rewrite data indefinitely. So for backups you don’t access often and want to keep for 5-10+ years, a traditional HDD is more suitable 2.

In general, SSDs work very well for short-term backups and data you need to access frequently. For true archival storage, HDDs are a better option due to their longer lifespan. Using a tiered backup approach with both an SSD and HDD can provide both speed and long-term reliability.

Conclusion

In summary, while SSDs provide fast access speeds and reliability against physical shock, they may not be the most suitable technology for long term archival storage and backups. The limited write endurance, potential for data retention issues after prolonged periods of inactivity, and lack of longevity compared to HDDs are factors to consider. Using SSDs in conjunction with other backup media, and migrating data periodically to new drives can help mitigate risks. But for truly archival storage spanning 5-10+ years, HDDs or tape may be better options. So in most cases, SSDs are likely suitable for short-medium term backups, but not ideal for indefinite archival storage. Their strengths lie more in performance, rather than longevity.