Hi there can anybody please tell me the optimal tunable disk settings for my server. Thanks 

 

M/B: Supermicro - X10SRA-F

CPU: Intel® Xeon® CPU E5-2683 v3 @ 2.00GHz

Memory: 32 GB Multi-bit ECC (max. installable capacity 512 GB)

Cache: 1TB Samsung 850 Evo

Drives: 1x8TB Parity, 10x8TB Array, 9x4TB Array

These usually work well:

 

Tunable (md_num_stripes): 4096
Tunable (md_sync_window): 2048
Tunable (md_sync_thresh): 2000

If you're sig is correct and you're still using the SAS2LP also change this one:

 

Tunable (nr_requests): 8

 

7 minutes ago, johnnie.black said:

These usually work well:

 

Tunable (md_num_stripes): 4096
Tunable (md_sync_window): 2048
Tunable (md_sync_thresh): 2000

If you're sig is correct and you're still using the SAS2LP also change this one:

 

Tunable (nr_requests): 8

 

 

Thank You

Is there a method to how you arrived at these numbers or has it been mainly through trial and error? How would cutting down the memory size to 8GB affect the numbers?

Look at this thread: 

 

I saw this script, but with it only having been updated 5 years ago and a few major tunables added/removed (Inside and outside the gui) I didn't want to assume it would work on the latest version of unraid (potentially giving tunables that are no longer relevant)...Does anyone know if the script is still relevant/usable for the latest version of unraid?

The script does not work anymore. I just tried it.

On 11/7/2018 at 10:46 PM, bsim said:

I saw this script, but with it only having been updated 5 years ago and a few major tunables added/removed (Inside and outside the gui) I didn't want to assume it would work on the latest version of unraid (potentially giving tunables that are no longer relevant)...Does anyone know if the script is still relevant/usable for the latest version of unraid?

All the tuneable options are right in the GUI, so I would think if they didn't matter LT wouldn't have included them there. I wish I knew enough coding to make this script work with the latest version of unraid. Would be nice to have the optimal settings. 

On 3/23/2018 at 5:52 AM, spencer785 said:

Hi there can anybody please tell me the optimal tunable disk settings for my server. Thanks 

 

M/B: Supermicro - X10SRA-F

CPU: Intel® Xeon® CPU E5-2683 v3 @ 2.00GHz

Memory: 32 GB Multi-bit ECC (max. installable capacity 512 GB)

Cache: 1TB Samsung 850 Evo

Drives: 1x8TB Parity, 10x8TB Array, 9x4TB Array

What controller are you using?

 

On 5/23/2019 at 12:01 PM, opentoe said:

All the tuneable options are right in the GUI, so I would think if they didn't matter LT wouldn't have included them there. I wish I knew enough coding to make this script work with the latest version of unraid. Would be nice to have the optimal settings. 

Hey, so I was poking around these forums looking for performance optimisations and this script seemed like the bees knees.  I got it to work on Unraid 6.7.0 by doing the following:

 

Open a root command window (console) in your favourite way.

type the folowing

root@yoursever:~# ln /usr/local/sbin/mdcmd /root/mdcmd

 

Then run the script as per normal.

 

Notably I'm getting some errors and I haven't bothered to fix them as it doesn't seem like they matter because I'm getting the output I need. Hope this helps you out.

 

I'd be interested if it works for you anyway - I got the following report with a Dell H310 card flashed in IT Mode:

That was the fast test, this was the normal test.  I have of course drives connected to the Dell H310 and the onboard SATA, so not sure what that does.

 

Saving doesn't work obviously (tried that) but you can enter them manually.  I assume that sync_thresh in Unraid is the same as sync_window in this script.

No. Those are different, IIRC.

Thanks - then not sure which to put where yet lol.  Also, despite what I read online, it seems read ahead is set to 256 not 1024, so setting it to 2048 seems to improve things.  i.e # blockdev --setra 2048 /dev/md*

My googling isn't working to tell me what the difference is - there doesn't appear to be a GUI option for the sync_window that I can see, so not really sure why it would be provided.

3 hours ago, Marshalleq said:

My googling isn't working to tell me what the difference is - there doesn't appear to be a GUI option for the sync_window that I can see, so not really sure why it would be provided.

 

I found this explanation:

 

 

On unraid 6.3.5 there are options for the following, so I imagine they are still there in later versions:

md_num_stripes

md_sync_window

md_sync_thresh

 

What disappeared was md_write_limit.

 

Here is explanation of the older tunables:

 

I tried to do what you said, still errored out.

 

There is a patched version of the script buried within the post

 

 

unraid-tunables-tester.sh

Hey unRAIDers!!

 

So, it's now, 2020; can anyone offer any advice as to whether or not the tunables script is to be trusted on unRAID v6.8.3? I was able to get the update from the link that @Squid provided working via cli (sort of) with errors; thanks to the post from @Marshalleq (example below):

/usr/local/sbin/mdcmd: line 11: echo: write error: Invalid argument
Test 1   - md_sync_window=384  - Completed in 601.464 seconds =  96.6 MB/s

The final "Best Bang for the Buck" results show the following...

 

On my production box (Supermicro [I suspect either] AOC-USAS-L8i, [or] AOC-USASLP-L8i)

          Current in disk.cfg   |      New Setting
    -----------------------------------------------
     md_num_stripes="4096"  | md_num_stripes="1536"
     md_write_limit=""  | md_write_limit="768"
     md_sync_window=""  | md_sync_window="640"
     
     Not Saved. Exiting.

 

and my backup box (2 Dell H310s):

 Current in disk.cfg   |      New Setting
    -----------------------------------------------
     md_num_stripes="4096"  | md_num_stripes="1280"
     md_write_limit=""  | md_write_limit="768"
     md_sync_window=""  | md_sync_window="384"

Type SAVE (uppercase) to modify disk.cfg

Not Saved. Exiting.

Any input, thoughts, etc. are much appreciated!! I feel like this is a message in a bottle, but I hope someone will respond soon. Thanks in advance!

Edited May 14, 20206 yr by Joseph
grammar

2 hours ago, Joseph said:

So, it's now, 2020; can anyone offer any advice as to whether or not the tunables script is to be trusted on unRAID v6.8.3?

No, v6.8.x uses a different engine, and it should mostly auto-tune, though there are some known issues for very large arrays, usually with 24+ devices.

8 hours ago, johnnie.black said:

No, v6.8.x uses a different engine, and it should mostly auto-tune, though there are some known issues for very large arrays, usually with 24+ devices.

@johnnie.black Thanks for the quick reply! I'll set all values to default then... fwiw, I'm running 20 drives in the array (incl. dual parity), also raid 1 cache on my production box and a few devices outside the array, so it sounds like I might be pushing it? Lemmie know. Thanks!!