As always, mine is in my sig.
@spikemixture said:
SSD CACHE POOL: 2x 500GB RAID1
Where do you see the benefit of running SSD as cache drives?
I assume Faster loading, Faster scanning, Faster streaming etc.?
You maybe spoilt now and can’t remmber what it was like pre SSD cache.How much faster ?
And if (when) you build again would you do it the same?
With UnRaid, all the dockers, plug-ins for the OS etc can be run from the cache pool. Also, uploads directly to the storage array can be slow due to having to make multiple writes to both parity drives as well as the data drive. So, uR implemented a cache pool system that when files are uploaded to a cache-sharing share, the files are actually uploaded to the cache pool (not the slower storage array) and made immediately available as if they were actually in the share you uploaded to. The file later gets moved to the array on a schedule.
I think the point you are trying to make is that the SSDs may seem overkill for a network limited to 1GB speeds. The cache pool serves two purposes for me: 1) faster upload speed than writing to the array directly and 2) ability to easily handle multiple processes (uploading, Plex clients streaming, Plex internal processes, etc).
short answer: faster, more fluid multitasking.
@interweb-tech said:
With UnRaid, all the dockers, plug-ins for the OS etc can be run from the cache pool. Also, uploads directly to the storage array can be slow due to having to make multiple writes to both parity drives as well as the data drive. So, uR implemented a cache pool system that when files are uploaded to a cache-sharing share, the files are actually uploaded to the cache pool (not the slower storage array) and made immediately available as if they were actually in the share you uploaded to. The file later gets moved to the array on a schedule.
Is their ever a need for it to be immediately available? I mean, a file is grabbed on your SSD cache and it takes about 2 minutes to copy it off to your device. Is that 2 minutes really needed? I ask because I am curious, I never understood the need for it, been using unRAID since 4.x beta days…
@don.alcombright said:
@interweb-tech said:
With UnRaid, all the dockers, plug-ins for the OS etc can be run from the cache pool. Also, uploads directly to the storage array can be slow due to having to make multiple writes to both parity drives as well as the data drive. So, uR implemented a cache pool system that when files are uploaded to a cache-sharing share, the files are actually uploaded to the cache pool (not the slower storage array) and made immediately available as if they were actually in the share you uploaded to. The file later gets moved to the array on a schedule.Is their ever a need for it to be immediately available? I mean, a file is grabbed on your SSD cache and it takes about 2 minutes to copy it off to your device. Is that 2 minutes really needed? I ask because I am curious, I never understood the need for it, been using unRAID since 4.x beta days…
With the launch of v6, the need as I see it is for running Dockers (PMS, etc). If you run them from the array, that share is always awake doing Plexy things. For my use case, cache pool is first and foremost a way to segregate the Dockers from the array and allow those drives to go to sleep.
