I was wondering I see that my array is running at 10 - 14 MB/s. Is this normal. I know that when I was running my parity I was getting around 180MB/s on all drives. The time this was taken I was using the Mover Service and moving files from my Cache Pool to the array.

 

I Have Unraid configured to run my Share Allocation method as Most Free instead of the High Water. This is because I wanted the data equally shared on all of my drives.

 

If I were to add more drives would I expect to see this speed go up. How can I increase the transfer rate?

3 hours ago, emsbas said:

array is running at 10 - 14 MB/s. Is this normal

It's normal if you're writing to all disks at the same time, which by the screenshot looks like you are, possibly using most free as allocation method?

Yes I am what I am wondering is if I add more drives to the array would that number increase or decrease. What I have happening is that because of this slow rate my cache is filling up and causing me issues.

If you care for write speed never user the most free allocation option, when writes switch from one disk to another parity writes will overlap making write speeds very slow, use hight water or fill up and this won't happen, also see turbo write for a faster write method (but still shouldn't be used with most free for best results).

I will give turbo write a try I have not implemented it. My thought process was that if I use Most Free Allocation method I hoped that Unraid would multi thread the writes to the drives which would allow for all of the drives to be use simultaneously. This would mimic the function of striping but not striping by bit but by file.

FYI Turbo Write increased my performance by about 40% which is great. I wonder if there is a way to optimize it more?

29 minutes ago, emsbas said:

I wonder if there is a way to optimize it more?

Don't use fill up.

Yea fill up is counter intuitive I  know unraid does a parity but the backup to the parity is having the option to only loose 1 drive worth of data that is on the array

57 minutes ago, emsbas said:

My thought process was that if I use Most Free Allocation method I hoped that Unraid would multi thread the writes to the drives which would allow for all of the drives to be use simultaneously.

It will use them all, and for reads that's fine. Writes all update the parity drive, so every time a write is requested, the system has to wait for the parity drive to commit before it can move on to the next write, regardless of which data drive is involved. If you wanted, I suppose you could get a hardware RAID card that is supported, and RAID0 a bunch of SSD's to use as parity.

Or just Raid 0 two 4tb drives or 4 x tb drives???

 

Rust Platters??

 

But doesnt Unraid Dislike that lol

Edited December 4, 20187 yr by emsbas

So to the same point if I had 2 parity drives it would be even slower.

 

I wonder if I just try to backup data to another unraid platform and use the slow parity there

Then switch this machine to no backup???

Just now, emsbas said:

So to the same point if I had 2 parity drives it would be even slower.

It would be the same, assuming both parity disks have the same characteristics/performance.

humm so Raid 0 two 8tb Red's ??

Should give me better performance on my Parity Maybe?

Likely not by much, the problem are the constant seeks, it would only be significantly faster with raided SSDs as parity.

Any other options being that 8tb of SSD's wont be fun... any thing else any one can think up

What about like a compute drive as my parity drive or a WD Black something with some more Balls??? Instead of a WD Red NAS. Maybe even like a 10k or 15k sas drive?

5 minutes ago, emsbas said:

Maybe even like a 10k or 15k sas drive?

Never tested but doubt it's fast enough.

We would guess it should be better though lol if not I guess ebay 8tb SSD slightly used lol

 

Edited December 4, 20187 yr by emsbas

I am wondering the 8tb Reds are 5400 RPM's

Would I see a gain if I switched my Parity drive to an 8TB Barracuda 7200 RPM?

Or even a 8tb 7200RPM SAS?

11 minutes ago, emsbas said:

Would I see a gain if I switched my Parity drive to an 8TB Barracuda 7200 RPM?

Possible very small gain. Probably not something you could feel except using a stopwatch and a consistent set of files.

So short of that it is what it is. Unless some how I can find an 8TB SSD for a parity lol.

Edited December 4, 20187 yr by emsbas

FYI Turbo Write increased my performance by about 40% which is great. I wonder if there is a way to optimize it more?

What are you doing as speed test here?

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I call it real world speed test lol.

 

I am transferring data from the Cache Drive to the Array that is where I noticed the speed difference. The file sizes are all the same roughly 1.5 to 5 GB

I call it real world speed test lol.
 
I am transferring data from the Cache Drive to the Array that is where I noticed the speed difference. The file sizes are all the same roughly 1.5 to 5 GB

My point being if it were over network, your bottleneck would probably be network and not the disks with those speeds

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It is over the network but I am running 10GB Lan SFP+ the write speed of the Cache is understandable being that I am transferring from a USB2.0 device but the Cache to Array speed is what doesnt make sense.