Parity Check Consumes All Disk Speed Preventing Docker Containers from Running

[kjcsg]

Hello,

 

I recently converted my HTPC setup to unRAID 6.8.3 and am loving it. I have run into one issue that my googling has yet to come up with a solution for. Any time parity check is running, whether it be from an unclean shutdown or scheduled, parity check eats up all the read/write speed of my disks running around 150MBps on average, with the CPU sitting around 20% and ram around 15%, so it's a disk usage problem. This in turn prevents my docker containers (Emby, LetsEncrypt w/ Nginx, etc) from running at all in the case of a startup parity check after an unclean shutdown. And if it runs after docker has the containers up and running, streaming any media or even using Emby is nearly impossible. I understand the purpose of the parity check after an unclean shutdown, but my parity checks take approximately 12 hours to complete, especially if it's happening when I get home from work and just want to watch something before bed. 

So my question is twofold; is there a way to limit the disk usage of the parity check or prioritize it lower than docker and docker containers so that Emby and my other docker containers are still fully functional during a parity check? I don't mind if the parity check takes longer as long as performance is prioritized to my docker containers. Or is there a way to disable the unclean shutdown parity check? I understand the risk entailed in doing so.

 

Thank you for any and all help!

[trurl]

Why are you having unclean shutdowns? 

 

Do you have cache?

[kjcsg]

We've been having some power outages and yesterday it froze up, couldn't even type in the username text box. I have an asrock rack motherboard with bmc and watchdog to recover in case of errors, but it usually does a hard reset when it does any recoveries, so that would start the parity check and disable the HTPC functions. 

 

I do have a cache drive, a 250gig samsung nvme m.2.

[trurl]

Go to Tools - Diagnostics and attach the complete Diagnostics ZIP file to your NEXT post in this thread.

[Squid]

On 8/11/2020 at 6:49 AM, kjcsg said:

So my question is twofold; is there a way to limit the disk usage of the parity check or prioritize it lower than docker and docker containers so that Emby and my other docker containers are still fully functional during a parity check?

Install the parity check tuning plugin, and schedule the check to run in multiple increments when there is nothing else going on (2 am for a couple of hours a day)

[trurl]

15 hours ago, kjcsg said:

I do have a cache drive

Diagnostics would tell whether cache is being used to make dockers more efficient.

[kjcsg]

On 8/12/2020 at 7:08 AM, trurl said:

Go to Tools - Diagnostics and attach the complete Diagnostics ZIP file to your NEXT post in this thread.

Attaching diag and syslog that I saved to the flash. You can see the time jumps in the syslog. Is there a debug mode to get more info in the logs? It seems the server is up and running for about 30 minutes before freezing up now and so I've been watching the temps and they're all solid around 30 degrees Celsius. 

 

On 8/12/2020 at 9:18 AM, Squid said:

Install the parity check tuning plugin, and schedule the check to run in multiple increments when there is nothing else going on (2 am for a couple of hours a day)

I set that up, which is helpful, but I still have to go in and cancel or pause the unclean parity check before the 6am start time I set. 

 

Edited August 18, 2020 by kjcsg

[Squid]

AMD Ryzen 7 1700 Eight-Core Processor

Have you read https://forums.unraid.net/topic/46802-faq-for-unraid-v6/page/2/?tab=comments#comment-819173, in particular setting the Power Supply Idle Control to be typical?

ASRockRack - X470D4U

Other than that, I find it curious that you're running a Ryzen 7 1700 on a Motherboard which in it's specifications only lists that it's 2nd and 3rd gen compatible, and the 1700 is most definitely not on its supported CPU list.  Doesn't necessarily mean anything, but I personally wouldn't have bought the combination...

[kjcsg]

12 hours ago, Squid said:

AMD Ryzen 7 1700 Eight-Core Processor

Have you read https://forums.unraid.net/topic/46802-faq-for-unraid-v6/page/2/?tab=comments#comment-819173, in particular setting the Power Supply Idle Control to be typical?

ASRockRack - X470D4U

Other than that, I find it curious that you're running a Ryzen 7 1700 on a Motherboard which in it's specifications only lists that it's 2nd and 3rd gen compatible, and the 1700 is most definitely not on its supported CPU list.  Doesn't necessarily mean anything, but I personally wouldn't have bought the combination...

That is the first I'm seeing of that thread and I changed the setting mentioned in it and it worked, the server has been up flawlessly for 6.5 hours now. Thank you. 

 

As for why I'm running that mobo with the 1700, I had the 1700 build with a different mobo running my server on Ubuntu with flex raid, but it had its issues and crashes so I got the mobo because it was an am4 ryzen mobo that had a watchdog and could auto recover from faults. I didn't look any deeper at it than seeing it was am4 and ryzen ready tbh. Once I get the money I'll upgrade to a Ryzen 3000 series chip.

 

Any tips on making it so my docker containers can run during a parity check? 

 

Thank you again. 

[trurl]

1 hour ago, kjcsg said:

Any tips on making it so my docker containers can run during a parity check? 

Get your appdata and system shares all on cache where they belong. They have files on the array where they will have performance impacted by parity, and where they will keep array disks spinning.

 

1. Settings - Docker, disable
2. Main - Array Operation - Move
3. Wait for it to complete and post new diagnostics.

 

[kjcsg]

On 8/13/2020 at 5:37 AM, trurl said:

Get your appdata and system shares all on cache where they belong. They have files on the array where they will have performance impacted by parity, and where they will keep array disks spinning.

 

1. Settings - Docker, disable
2. Main - Array Operation - Move
3. Wait for it to complete and post new diagnostics.

 

Alrighty, I set the appdata and system shares to only for the use cache drive setting. Is that the best choice for that setting?

 

Edited August 18, 2020 by kjcsg

[trurl]

7 hours ago, kjcsg said:

Alrighty, I set the appdata and system shares to only for the use cache drive setting. Is that the best choice for that setting?

Looks good. You might consider moving domains share to cache also but I didn't mention it since you didn't have VMs enabled. Depends on how you configure VMs to use storage.