kaine1688

Cache Drive Suggestions

16 posts in this topic

So after reading many threads on NAS software and the fact that I don't want just a storage computer I decided to bite the bullet and make a quite overkill server, but I need some help with the cache pool drives.

 

Is there a common rule of thumb on the size of drives you should be using, I will definitely do a cache drive with a parity in-case one fails.

System specs:

mobo: Z10PE-D16 WS

cpu: 2x e5-2690v4

ram: 4x16 ECC

case: supermicro with 1200W dual psu, 24 hot swaps

gpu: W5900 2gb

HBA: 2278300-R Adaptec SAS HBA 71605H Single

drives: 6x8TB (2 parities) helium drives, i have a crapton of 4tb greens and reds but I will use them in a separate enclose as backups.

 

I plan to run Plex, emby, torrent, couchpatoate, and other things related to media library, owncloud, teamspek server, retro game server, probably 2 Windows 10 VMs, and a Ubuntu VM to learn.

 

Anyways, i wonder if 2x1TB enterprise SSDs will do for cache or would 2x2TB drives be a better choice. There has been days that between moving data files and light torrents I can probably move over 1TB of data in one day. Question is how does unRaid handle this, does it just accumulate the data and move it all at night.

 

Is it possible to fill up the cache drive? Will it just start moving files to spinner HDDs at some point once it starts filling up?

 

Thanks for filling in my noobnes on this subject.

0

Share this post


Link to post
Share on other sites

You set the schedule for running the mover. As often as once an hour to as few as once a month. If you ran it twice a day, 2x1TB SSD would be more than enough and you can configure as RAID1 cache pool so you have some redundency on the unprotected data until it gets moved to the array. Its also where all your VMs & Dockers will live.

 

I have 2x275GB in RAID1 and run once a day @3 AM. Never more than half full.

0

Share this post


Link to post
Share on other sites

Sounds great, so if the VMs live there, basically the more VMs you want, the more space you should have then.

 

How about torrents, do they live on the cache drive like everything else till completion?

 

0

Share this post


Link to post
Share on other sites

How about torrents, do they live on the cache drive like everything else till completion?

Everything else doesn't store on cache.

 

Each user share can be configured to use cache or not. Files written to array disks will never use cache.

 

If you save your torrents on a user share that is configured to use cache, then they will stay on cache until they are closed and then moved on schedule. Mover will not move open files.

0

Share this post


Link to post
Share on other sites

Looking through the forums, there has not been a lot of talk regarding NVMe or PCIe based SSDs as of lately.

 

Are there any of these SSDs that are compatible and usable as cache drives?

0

Share this post


Link to post
Share on other sites

Are there any of these SSDs that are compatible and usable as cache drives?

 

All NVMe devices should work with v6.2 and above.

0

Share this post


Link to post
Share on other sites

Looking through the forums, there has not been a lot of talk regarding NVMe or PCIe based SSDs as of lately.

 

Are there any of these SSDs that are compatible and usable as cache drives?

 

Running 6.2.4 and a 950 pro, it hasn't missed a beat. Those things do tend to run a little bit warm, though.

0

Share this post


Link to post
Share on other sites

Ended up getting a sweet deal on 2 SM863 960GB, cheaper than a 850 equivalent :o

 

Now waiting on 7x HGST he8 8TB HDDs 7.2k RPM, i am not looking forward to moving 30TB of data or so....

 

Assuming I should turn off caching until I move all of the data right?

0

Share this post


Link to post
Share on other sites

Yes, no point in using cache for the initial data dump, you should enable turbo write, that will make a big difference.

0

Share this post


Link to post
Share on other sites

Maybe even consider turning on turbo-write (or copy over w/o parity protection since you will still have a copy of the data should disaster strike.

0

Share this post


Link to post
Share on other sites

Thank you guys for all the suggestions, I finally got all my drives. Will be doing the build over the weekend. UnRaid here i come.

0

Share this post


Link to post
Share on other sites

I just changed to an ADATA SX8000 NVMe SSD, it's really nice.  Quick enough for unRAID, uses MLC memory (so will last longer than TLC), and runs a LOT cooler than Samsung drives.  The ADATA runs at 35C, the Samsung drives were closer to 60C or more.  Was a good price too.

0

Share this post


Link to post
Share on other sites

I was going to go the NVMe route, but my workstation board is c612 chipset and only has 1 m.2 slot, and I prefer redundancy, plus 2 SM863 960GB will serve me well, read/write isnt the greatest, compared to my 850, but it is more suited to server use, plus i got 2 for $240...........cant go wrong there.

 

Hows the heat on those NVMe, I have a 750 pcie and those tings get HOT, kinda why I always stayed away from m.2, with no heatsinks I can only imagine?

0

Share this post


Link to post
Share on other sites

How about torrents, do they live on the cache drive like everything else till completion?

Everything else doesn't store on cache.

 

Each user share can be configured to use cache or not. Files written to array disks will never use cache.

 

If you save your torrents on a user share that is configured to use cache, then they will stay on cache until they are closed and then moved on schedule. Mover will not move open files.

 

I watched a video the other day that explained that putting a SSD cache drive in helps with transfer speeds eg putting the files your transferring to cache first then the "mover" moves them later.

 

If i was to put a cache drive in do i need to enable this ? eg to write to the cache first then the server moves it to the array later or is this enabled by default if the server has a cache drive /

 

my setup is a Parity drive 1 2TB drive and a 128g SSD for cache - if i take the cache drive out would the transfer speeds drop as its writing to the parity drive instead of SSD first ?

 

thanks for reading

 

Happy Nassing

0

Share this post


Link to post
Share on other sites

Seems to me like your question was already answered in my post that you quoted.

How about torrents, do they live on the cache drive like everything else till completion?

Everything else doesn't store on cache.

 

Each user share can be configured to use cache or not. Files written to array disks will never use cache.

 

If you save your torrents on a user share that is configured to use cache, then they will stay on cache until they are closed and then moved on schedule. Mover will not move open files.

 

I watched a video the other day that explained that putting a SSD cache drive in helps with transfer speeds eg putting the files your transferring to cache first then the "mover" moves them later.

 

If i was to put a cache drive in do i need to enable this ? eg to write to the cache first then the server moves it to the array later or is this enabled by default if the server has a cache drive /

 

my setup is a Parity drive 1 2TB drive and a 128g SSD for cache - if i take the cache drive out would the transfer speeds drop as its writing to the parity drive instead of SSD first ?

 

thanks for reading

 

Happy Nassing

0

Share this post


Link to post
Share on other sites

So the server is working out great, took 4 days to move all the data..........but it is done, dockers are awesome! Thanks again to everyone who explained the extra details for me.

0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now

Copyright © 2005-2017 Lime Technology, Inc. unRAID® is a registered trademark of Lime Technology, Inc.