ButchR Posted December 7, 2021 Share Posted December 7, 2021 (edited) I have the following CPU_IOWAIT errors on my UNRAID: I have research this error a little and there is some older information available with maybe issues with older versions of UNRAID. Some discussions related to Mover and/or Samsung drives starting at a different location causing a delay of data transfer (not very clear). Is there a definitive answer or maybe a guide to solve the problem? Edited December 7, 2021 by ButchR mistake Quote Link to comment
Squid Posted December 7, 2021 Share Posted December 7, 2021 It really all depends upon what's going on at the time. IO wait isn't an "error" per se. It just means that the system is hung up waiting for data to arrive from an I/O device (most likely hard drive(s)) But, if you started your journey with Unraid prior to (I believe) 6.8.x, then at some point you should be reformatting your cache drive to take advantage of increased speeds IF the partition doesn't start on sector 64. Quote Link to comment
ButchR Posted December 7, 2021 Author Share Posted December 7, 2021 I am fairly new to UNRAID and learning how to troubleshoot and resolve some issues. How can I determine what the bottleneck is via the data I supplied. Could recommend some steps to troubleshoot this issue? Quote Link to comment
ButchR Posted December 7, 2021 Author Share Posted December 7, 2021 Just been trying a few things to resolve this issue. My Plex output is not stable getting snow filled video, replaying video and freezing. I pinned CPU to 5 cores and notice CPU_IOWAIT has reduced to 2 entries: Quote Link to comment
ButchR Posted December 8, 2021 Author Share Posted December 8, 2021 Well I started my journey with UNRAID at 6.8.x. I am at version 6.9.2 right now. What steps do I need to take to have my Samsung's drives (SSD & Samsung 970_EVO) to start at sector 64? Any help would be appreciated. My Plex is is not stable. I been reading about formatting drives, which is understandably a needed step. Most of the comments assumed the reader was familiar with the process and/or UNRAID. Just need some help to achieve the end result of starting at sector 64 that hopefully will resolve this issue. I hope that I can achieve some successful help from the community. Thanks in advance. Quote Link to comment
ButchR Posted December 9, 2021 Author Share Posted December 9, 2021 Unsuccessful so far in finding the issue that causing my URAID/ Plex server to be so unstable. I had a few months of Plex server running great. Now, I thinking maybe I will have to start over from the beginning. Reading and trying a few things and wondering how it could have gone so wrong . Only if I could decipher the critical warnings better. Making list of things to try and crossing them off my list. Wish me luck and will need it for sure. Quote Link to comment
ButchR Posted December 14, 2021 Author Share Posted December 14, 2021 Still researching information on cpu_iowait and troubleshooting my unraid server issues. Attached a diagnostic file and screen capture. from Glances. Also, netdata information Any help will be greatly appreciated. thecave-diagnostics-20211213-1859.zip netdata-TheCave-20211213-190202-720.snapshot Quote Link to comment
ButchR Posted December 14, 2021 Author Share Posted December 14, 2021 I have exhausted trying things that I have discovered with the help of the forum. My Unraid server had been running good for three months. At the present time it is not stable enough to run Plex with out crashing or not functioning al at all. What are so basic steps I can take to start over? I thinking of cause use my flash and slowly add hardware back one step at a time. Hopefully, I will be able to get my Unraid server back running. Any help with steps or guides on how to start over with an unstable Unraid server from scratch. Quote Link to comment
Zonediver Posted December 14, 2021 Share Posted December 14, 2021 (edited) Is the CPU or RAM overclocked? Edited December 14, 2021 by Zonediver Quote Link to comment
ButchR Posted December 14, 2021 Author Share Posted December 14, 2021 No overclocking setup... Quote Link to comment
Zonediver Posted December 14, 2021 Share Posted December 14, 2021 26 minutes ago, ButchR said: No overclocking setup... Can you provide a full list of your Hardware please? Quote Link to comment
ButchR Posted December 14, 2021 Author Share Posted December 14, 2021 Here is a list of the hardware: Supermicro Motherboard MBD-X11SCA-F-O Intel Core i9-9900K 3.6 GHz Eight-Core Corsair Vengeance LPX 8GB (1 x 8GB) DDR4 DRAM 2400MHz (PC4-19200) Corsair Vengeance LPX 8GB (1 x 8GB) DDR4 DRAM 2400MHz (PC4-19200) Dell 6Gbps H310 SAS HBA w/ LSI 9211-8i P20 IT Mode HP NVIDIA Quadro P620 Graphics Card - 2GB GDDR5 Parity ST6000VN001-2BB1_ZR10HA6A - 6 TB (sde) Disk 1ST 6000VN001-2BB1_ZR10J15M - 6 TB (sdf) Disk 2 WDC_WD60EFAX-68S_WD-WX11D192V428 - 6 TB (sdc) Disk 3 ST4000DM004-2CV1_ZTT15GZD - 4 TB (sdl) Disk 4 WDC_WD40EZRZ-00G_WD-WCC7K7PA29TT - 4 TB (sdm) Disk 5 WDC_WD40EZRZ-00G_WD-WCC7K7PA267U - 4 TB (sdb) Disk 6 ST4000DM004-2CV1_ZTT17LGL - 4 TB (sdg) Cache_nvme Samsung_SSD_970_EVO_Plus_2TB_S59CNM0R419774J - 2 TB (nvme1n1) Pool of two devices Cache_protected SHGS31-500GS-2_ED0CN90861140CP4E - 500 GB (sdh) Cache_pr...ted SHGS31-500GS-2_EN08N831310208U2A - 500 GB (sdj) Cache_ssd CT1000BX500SSD1_2110E583F484 - 1 TB (sdd) Pool of two devices Ssdpool_test Samsung_SSD_850_EVO_250GB_S3PZNF0JC10412H - 250 GB (sdk) Ssdpool_test 2 Samsung_SSD_850_EVO_250GB_S3PZNF0JC08916B - 250 GB (sdi) Vms_nvme WDBRPG0010BNC-WRSN_205348801911 - 1 TB (nvme0n1) Quote Link to comment
ButchR Posted December 15, 2021 Author Share Posted December 15, 2021 Updated diagnostics.. thecave-diagnostics-20211214-1803.zip Quote Link to comment
Zonediver Posted December 15, 2021 Share Posted December 15, 2021 Maybe this mainboard and the Samsung-SSDs doesnt work togethter well... just a guess... Quote Link to comment
Squid Posted December 15, 2021 Share Posted December 15, 2021 On 12/13/2021 at 10:15 PM, ButchR said: Still researching information on cpu_iowait and troubleshooting my unraid server issues. Attached a diagnostic file and screen capture. from Glances. IO wait simply means that the CPU is waiting for information from a device. It all depends upon what's going on at the time this is happening. Now if you're seeing that spike on the hour, every hour its because you're trimming the drives far far too often than necessary. Once a week during off times is more than sufficient. Everything gets hung up while that's going on. Quote Link to comment
ButchR Posted December 15, 2021 Author Share Posted December 15, 2021 Okay How do make adjustments to drive trimming ? Any information you could provide? Also, I read where Samsung drives need to be reformatted for a different starting bit for Samsung drives. I have used hard drive utilities in the past to partition etc. . Do I need to use some software like that to prep the Samsung drives? Do you know the steps I need to take? Quote Link to comment
ChatNoir Posted December 15, 2021 Share Posted December 15, 2021 1 hour ago, ButchR said: Okay How do make adjustments to drive trimming ? Just go to the Scheduler (settings/scheduler) and adjust the frequency to once a week and time to some downtime. Quote Link to comment
ButchR Posted December 15, 2021 Author Share Posted December 15, 2021 Thanks. Okay this is my adjustments: Quote Link to comment
ButchR Posted December 15, 2021 Author Share Posted December 15, 2021 Okay here is a refence shot of my Unraid: Quote Link to comment
ButchR Posted December 16, 2021 Author Share Posted December 16, 2021 After making the trimming adjustments yesterday still getting cpu_iowait warnings. Quote Link to comment
ButchR Posted December 19, 2021 Author Share Posted December 19, 2021 Help. How can I reverse engineering my Unraid server? I am not getting anywhere with my troubleshooting on this issue. Has anyone dial it back on their handicapped Unraid server? Quote Link to comment
Squid Posted December 19, 2021 Share Posted December 19, 2021 This is completely a bandwidth issue with multiple concurrent I/O's happening and the system having to wait to complete. EG: You appdata share exists on two of the cache pools and on the array. This may be by design, but it existing on the array is going to be a huge penalty. The same with the system share (this won't affect anything unless within the system share the docker.img is the file that's existing on the array) The worst case for this happening with say Plex is buffering, stuttering etc. It won't cause any crashes. Crashes would be something else. The graphs in Netdata showed that the I/O wait stopped. The key to diagnosing is figuring out what is changing with what's going on at the point in time when the I/O wait increases to the point its causing issues and what changed when the I/O wait drops back down. Quote Link to comment
ButchR Posted December 19, 2021 Author Share Posted December 19, 2021 I see how, not by design I have set up bandwidth bottlenecks. I as a novice unraid user I took a little from various guides and videos to create my dream unraid server. I overlap or doubled share locations and set a share in an inefficient location. Now I have conflicting I/O's ; appdata on two shares and cache pools on the array. I would like to correct these issues and have a standard setup for I/O's. Then I could learn the functions of shares and modify in the future if needed. What steps can I take to perform surgery on the unraid server's setup to make the setup more efficient? Quote Link to comment
ButchR Posted December 20, 2021 Author Share Posted December 20, 2021 Here is what my shares look like. I have added apps that look cool but have not totally implemented. So I am open to remove any apps that may look like an issue. Help with removing conflicts and setting up a move efficient structure were be so appreciated. To correct: "multiple concurrent I/O's happening and the system having to wait to complete.". "appdata share exists on two of the cache pools and on the array" Efficient "system share" . Quote Link to comment
ButchR Posted December 22, 2021 Author Share Posted December 22, 2021 Any suggestions how I can start to make changes to my unraid shares? I thinking to create basic share structure and build on the basic structure. I wish I was an expert with unraid to know what moves to make next. Just like learning chess for the first time. After sometime playing chess one knows what moves to make. I am a little frustrated that all I put in my unraid server so far is not working well. Hopefully one day I get my unraid server where I would like ....... Quote Link to comment
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