Best way to configure drives for new installation

[Medwynd]

For my build I have:

4 x 3TB WD Red drives

2 X 4TB HGST NAS drives

1 X 250GB Samsung EVO SSD

1 or possibly 2 2TB WD Green

 

I believe the proper setup would be:

Data drives:

4 X WD Reds

1 X HGST

 

Parity drive:

1 X HGST

 

Now, I would ideally only like to use the SSD to run my virtual machines, as it is small but fast and I would be doing all of the plex transcoding to this drive.

 

I would then probably use a 2TB Green drive, assuming they pass preclear as I want to stress them since they are pretty old,  as the cache drive.

 

Does this seem like a proper way to set this up?  Would I then setup the SSD to not be managed by unraid in anyway since it will not need to copy information to the array?

[tdallen]

Yes, assuming you want to use a cache drive to cache writes to the array.  You'll want to use the Unassigned Devices plugin for the SSD.

[trurl]

But many people aren't very concerned with caching a lot of user share data, and just use their SSD as a cache/app drive. I have SSD for cache, but I don't cache anything, just have apps there. It is simpler to let unRAID manage the cache disk than it is to use a drive outside unRAID management.

[Medwynd]

But many people aren't very concerned with caching a lot of user share data, and just use their SSD as a cache/app drive. I have SSD for cache, but I don't cache anything, just have apps there. It is simpler to let unRAID manage the cache disk than it is to use a drive outside unRAID management.

 

So you are suggesting just using the SSD as the cache drive but not actually caching anything there?  Just use it to hold the vms and any app data needed, such as the plex database?

 

When I am orginally setting up the server I will have well over the 250GB of space that the SSD holds.  Can I copy directly to the array if there is a cache disk present?  Or does it only get cached if you copy data to the cache, then the mover will move it at a later time?

[trurl]

But many people aren't very concerned with caching a lot of user share data, and just use their SSD as a cache/app drive. I have SSD for cache, but I don't cache anything, just have apps there. It is simpler to let unRAID manage the cache disk than it is to use a drive outside unRAID management.

 

So you are suggesting just using the SSD as the cache drive but not actually caching anything there?  Just use it to hold the vms and any app data needed, such as the plex database?

 

When I am orginally setting up the server I will have well over the 250GB of space that the SSD holds.  Can I copy directly to the array if there is a cache disk present?  Or does it only get cached if you copy data to the cache, then the mover will move it at a later time?

Disk shares (if you use them) are not cached. Only user shares are cached if you set them to be, and whether to cache or not can be set for each user share independently.

[Medwynd]

http://lime-technology.com/setting-up-your-file-structure-and-user-shares-on-unraid/

 

I read this article on user shares, and i think i get the idea.  How would a disk share differ?  So none of your user shares are set to be cached?

[trurl]

http://lime-technology.com/setting-up-your-file-structure-and-user-shares-on-unraid/

 

I read this article on user shares, and i think i get the idea.  How would a disk share differ?  So none of your user shares are set to be cached?

No user shares cached except for VM and appdata, which are set to cache-only, so they just stay on the cache. Write speed is unimportant to me because most of the data written to my server is unattended scheduled backups from other computers, or unattended downloads.

 

VM and appdata live on cache so they will not be impacted by parity write speed, and also will not make the parity disk spinup.

[tdallen]

So you are suggesting just using the SSD as the cache drive but not actually caching anything there?  Just use it to hold the vms and any app data needed, such as the plex database?

Yes.  A lot of us do that.  Writes to the array are reasonably fast and we like the idea that our data is protected immediately, rather than after mover runs in the early morning hours.  My "apps" user share is the only one I have configured to use cache, and I have that set as "cache-only" so it resides strictly on the cache drive and won't get moved to the array by mover.  I actually tend to refer to the cache drive as the application drive these days.

 

By the way - a common strategy when you are setting up a new server is to defer setting up the parity drive until after the data is loaded.  That way, writes to the array will occur at full speed during the initial load.  After all your data is loaded, then setup parity and let it sync.  If you use this strategy make sure you data is secure in it's original location - your data won't be protected on unRAID until the parity sync occurs.

[Medwynd]

Thanks for the tips.  The last of the hardware arrived today so hopefully Ill be able to do the build tonight.