# Immich Thumbnail Storage Guide: SSD Size for Generated Media Thumbnails and transcoded derivatives are easy to ignore because they are not the original photo library, yet they still consume real storage and can grow as the library expands. The safest approach is to treat generated media as a measurable working-data layer, give it its own planning allowance and leave free space for regeneration rather than filling the SSD to its advertised capacity. ## Buying answer Plan generated-media storage as a percentage of your projected original library, then adjust the percentage after measuring your own server. A 1TB SSD can be a practical working tier for many households, while larger video-heavy collections or multi-year growth plans may justify 2TB or more. Keep original photos and videos protected independently because generated files are not a replacement for source media. ## Buying guide ### Generated media is a real capacity layer Immich creates working data that is separate from the source photo and video library. Thumbnails make browsing practical and transcoded derivatives can support playback workflows. Even though these files can often be regenerated, they still occupy space during normal operation. Treating them as a dedicated planning layer prevents the application SSD from becoming unexpectedly full after a large import or a change in the library’s video mix. ### Use a percentage as a starting model There is no single thumbnail percentage that fits every library because photo resolution, video share, transcoding behavior and application settings differ. A planning percentage is useful precisely because it is adjustable. Start with a reasonable allowance, then measure the actual generated directories after the server has processed a representative portion of the collection. Replace the planning assumption with your own observed ratio as soon as real data is available. ### Video-heavy libraries need more caution A photo-only archive and a collection full of phone videos can create very different working-storage pressure. Transcoded video can consume substantially more space than image thumbnails, and a family that records high-resolution clips may see the generated layer grow quickly. Increase the generated-media allowance when the collection is video-heavy rather than assuming every terabyte of originals creates the same overhead. ### Why SSD storage is attractive here Thumbnails and generated files are accessed frequently during browsing and background work, so solid-state storage can make this layer responsive without requiring the entire original archive to live on flash. A 1TB or 2TB internal SSD is often easier to cool, replace and manage than scattering application data across several small devices. The best capacity depends on projected library growth and whether the SSD also hosts the database or other containers. ### Separate original importance from generated convenience Original uploads are irreplaceable user data unless another independent copy exists. Generated thumbnails and transcodes have different recovery value because the application can recreate them from originals under the right conditions. This difference should affect backup strategy. You may back up the whole application volume for faster restoration, but the protection priority for originals and database state should remain explicit even when generated files share the same device. ### Leave free space for regeneration A regeneration job can temporarily increase write activity and storage pressure. Planning an SSD to operate nearly full leaves little room for rebuilds, updates or temporary files. Leave a meaningful free-space reserve so normal operation retains headroom instead of choosing an SSD whose advertised capacity barely matches the current generated directory. ### Database and thumbnails can share a drive For a compact home server, one reliable internal SSD can hold the database, application data and generated media. This keeps the system simple and reduces device count. The trade-off is that capacity and write activity from all roles accumulate on one SSD. Size for the combined workload, keep database backups independent and avoid assuming that a drive sized only for PostgreSQL will automatically have enough room for years of generated media. ### A second SSD can simplify large libraries When generated data grows into the terabyte range, a second SSD can create a clean operational boundary. The primary application drive remains modest and easy to back up, while the larger SSD absorbs thumbnails and transcodes. This separation can also make migrations less disruptive. It is not mandatory, but it becomes attractive when a single application drive would otherwise need to be oversized mainly because of regenerable files. ### SATA can be economical for large generated sets Generated media may benefit from SSD latency without requiring top-end NVMe throughput. If the server has spare SATA bays and limited M.2 slots, a larger SATA SSD can be a cost-effective working-data tier. The decision should account for cabling, bay availability, power, airflow and future expansion. Use NVMe when it fits naturally; do not spend on an interface solely because a benchmark chart places it above SATA. ### Track actual usage after major imports Capacity plans should be revisited after a bulk migration, a phone upgrade that changes video behavior, or a major Immich configuration change. Record original library size and generated-data size at the same point in time. That observed ratio gives you a stronger forecast than generic guidance. If the ratio rises, update the growth model before the SSD is close to full rather than waiting for a low-space warning. ### Do not delete generated files without a recovery plan Generated content may be recreatable, but regeneration can take time and compute resources, especially for a large archive. Before clearing a generated directory to reclaim capacity, understand the current Immich maintenance process and what will rebuild automatically. A storage problem should not be solved by deleting directories blindly. Capacity planning is safer than emergency cleanup because it preserves the application’s expected data relationships. ### Buy for the next growth interval The right SSD capacity is the size that survives the next planned growth interval while retaining free space. Compare 1TB, 2TB and 4TB options using live price, interface, endurance and host compatibility, then choose the smallest class that preserves a comfortable margin. This avoids both extremes: paying for unused flash far beyond the expected workload or buying so tightly that another migration is needed within months. ## Live Amazon prices See the canonical page for current or last-valid marketplace evidence.