Question hdd, ssd, temperature humidity

• No — HDDs don’t suffer the same charge‑loss issues as NAND flash, so they’re generally better for long “cold” storage than SSDs. However magnetic media still can slowly degrade (thermal agitation, bit‑decay, rare radiation events, mechanical failures) so data can become corrupted over many years if left completely untouched. Periodically powering/reading the drive helps you detect problems and can reduce risk, but it does not make an HDD immortal.
• Practical rule of thumb used by many: verify/check archived HDDs on a schedule (annual or every 1–2 years for risky environments; every few years in good conditions) and plan to migrate important archives to fresh media every ~5–7 years. That combination (verification + migration + redundancy) is what keeps archives safe.

• There’s no single “perfect” number, but the ideal storage window for long‑term retention is cooler and drier (roughly 20–25°C and humidity below ~50% RH). Higher temperature and higher humidity accelerate chemical and physical aging and increase the risk of corrosion and condensation — which can cause real damage over time. Your 33–38°C and 55–66% RH are warmer and more humid than ideal and will raise long‑term risk (especially humidity above ~60% and any chance of condensation). That said, those conditions by themselves are unlikely to instantly “demagnetize” the platters; demagnetization usually requires very strong external fields or extreme temperatures.
• Corrosion/oxidation is the real environmental threat in humid conditions — metallic parts, connector pins, and electronics can corrode if moisture is present. Avoiding condensation and controlling humidity around the drives are the main protective actions.

1. Use redundancy: keep at least 2 independent copies of any important archive (3-2-1 rule recommended: 3 copies, 2 media types, 1 off-site).
2. Verifications and checks:
   • Compute and save checksums (SHA256) for your files or images and re‑check them during each audit. In PowerShell: Get-FileHash C:\path\file.iso -Algorithm SHA256.
   • Check SMART attributes (CrystalDiskInfo or hdparm) when you power the drives to catch reallocations / pending sectors.
3. Power/verify schedule:
   • Continue powering/reading them once a year if that’s what you can do; given your higher temperature/humidity I’d recommend at least yearly verification, and consider copying the data to a fresh drive every 3–7 years for critical data.
4. Storage containment to reduce humidity effects:
   • Store drives in airtight containers or anti‑static bags inside a drawer/box. Add fresh silica‑gel desiccant packs (and replace/regenerate them periodically). Use insulated boxes to buffer temperature swings. These measures help even when you cannot control the room climate.
5. Avoid condensation:
   • Don’t move drives from hot to cold locations rapidly; allow gradual acclimatization in their container. Keep drives off floors and away from windows / direct sunlight. If you can add a small fan for ventilation or place drives in a part of the house that runs a bit cooler, that helps.
6. Keep magnets / CRTs in perspective:
   • Everyday electronics (a turned‑off CRT a half‑meter away, or internal DVD drives) are unlikely to demagnetize a modern HDD. Extremely strong fields or very close proximity while devices are energized would be the risk. Still, keep drives a reasonable distance from large speakers or old CRTs if practical.
7. Consider alternative/extra archival media for the most important data:
   • M‑DISC optical media or LTO tape (enterprise/archive solutions) or cloud cold‑storage are options that reduce dependence on one HDD and are designed for long retention.

• Give a short checklist you can follow when you “energize” a drive (what to run, what SMART attributes to look for).
• Provide a PowerShell script to create and verify SHA256 hashes for entire folders or disk images.
• Recommend specific humidity/temperature buffering containers or desiccant pack sizes.

samHoney said:

It’s normal to worry about long-term data retention, but HDDs generally don’t need periodic rewrites like SSDs. As long as the drive is healthy, the magnetic domains stay stable for many years. Bitrot can happen, but it’s rare on spinning disks unless the drive itself is failing.


Your humidity and temperature range isn’t ideal, but it’s not catastrophic either. HDDs are pretty tolerant as long as there’s no condensation and the drive isn’t powered on while overheated. For long-term storage, just power them up once a year, let SMART run, and keep them in a cool, stable place if possible.

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nandobadam88 said:

Can 2.5" HDDs be used for long-term archiving, or are only 3.5" HDDs suitable for that purpose?

Is my daily temperature variation of 30-38°C (55-66%) over 24 hours (without rain) very critical for the long lifespan of 2.5" HDDs, even if they are only used once a year?

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• Magnetic data retention (bit‑decay) is not the same bug as NAND charge loss — HDDs don’t need the same frequent rewrites as SSDs — but higher temperature and humidity accelerate slow magnetic decay and increase corrosion risk over years. That raises long‑term failure probability if drives sit in 31–38 °C and 55–66% RH.
• Powering a drive daily increases mechanical stress (spindle, bearings, head parking cycles) and exposes the electronics to more hours of operation and thermal stress, which can shorten life in other ways. HDDs are mechanical devices and are subject to wear if run frequently.
• Annual power‑ups help you detect problems (SMART warnings, bad sectors) but do not “reset” magnetic ageing; they are a monitoring step, not a cure. Frequent powering only helps if you use that opportunity to verify and refresh data — otherwise it merely trades one failure risk (mechanical wear) for another (accelerated thermal aging while powered).

1. Treat drives as monitored cold storage, not “set and forget” archives: keep doing a scheduled power‑up + verification — at least once per year; given your hot/humid climate, consider increasing checks to every 6–12 months.
2. On each check: run SMART, read a sample of files, and verify checksums (e.g., SHA256) so you catch silent corruption early. If you find errors, copy the data immediately to fresh media.
3. Use redundancy and migration: keep at least two independent copies on separate drives (3‑2‑1 principle) and plan to migrate critical data to new media every ~3–7 years (shorter in your environment).
4. Reduce humidity exposure: store drives in airtight boxes or anti‑static bags with fresh silica‑gel desiccant and an insulated container to buffer temperature swings. That lowers corrosion risk far more effectively than frequent powering.
5. If you must power them more often, use that time to verify and (if needed) rewrite files — don’t just spin them idly. Avoid heavy writes while the drive is hot; let drives acclimate in their container before powering.
6. Consider alternate/extra archival options for your most important data: M‑DISCs, LTO tape, or cloud cold storage — these are designed for longer retention under poor local climate conditions.

• Post a short checklist you can run when you “energize” a drive (SMART checks + commands), or
• Provide a PowerShell script to create and verify SHA256 hashes for a folder or disk image. Which would you prefer?