QuTS hero 6.0 Public Beta - “CACHED Storage and QTier”

Beta Program Archive QuTS hero h6.0 Beta
1

Thanks for CACHE new feature implementation, Now for manage CACHE content I can choose what data for me are need to cache and what data not need.

Will be nice to implement there also request quantity when data will be cached and cache time, when data will be expired.

Screenshot From 2026-01-07 11-40-32
Screenshot From 2026-01-07 11-40-321187×628 91 KB

QNAP Team can you please explain what happen, when on the same device will be nvme ssd for cache and additional nvme for qtier in same disk pool.

If DATA migrated from cold drive (SAS/SATA HDD) to qtier hot drive(nvme SSD) and than requests come and data will be cached?

How NAS QuTS hero working in this situation, because both cache and qtier is nvme!

How data migrated?

Where is priority request and maybe I can define what data will be in qtier and what data in cache?

Best regards

2

Forum users here generally recommend that cache not be used. It is does not work well and can actually slow things down.

3

QuTS is using native ZFS cache..so that should not be broken.

Still cache has limited use cases l, useful for some cases, useless for others.

Only advantage for Qtier would be the addition of usable space of the extra bays and the option to remove this space again (vs. destruction of all data on normal mixed array pools)

4

Does there is methods, how cache or qtier tested, can you provide test methods or results if they are available?

5

Actually it depends on your workflow. You should try your concerned workflow and just meter the performance.

I think the main concerns on cache include:

  • Sequencial IO speed of HDD is usually not worse than network speed, especially when there’s a large RAID. Cache will not help sequencial IO in this case.
  • QTS (not QuTS hero) had a strange policy of moving data from write cache to underlying storage. This was widely discussed in the old QNAP forum where many people reported that writing performance will greatly degrade and even become slower than a single HDD without cache when write cache disks are full.

If you have spare SSD and spare time, trying out every setup and meter them will give you all the answer. Also posting your results will let others better understand the situation.