VM's going really slow after 3 - 4 weeks
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@Gheppy I was surprised to see a graylog VM using so much CPU, but maybe it's normal.
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Yes, it is a VM with a heavily used database.
At the moment I am trying to convince them to buy an XO license for this server.
I work for a public service and I have no say when it comes to money. -
@Danp said in VM's going really slow after 3 - 4 weeks:
@Gheppy I was surprised to see a graylog VM using so much CPU, but maybe it's normal.
Not sure if Gheppy DB is graylog. Mine was and when I searched for an answer as to why the strange CPU utilization came up with the same answer Oliver supplied.
I would like to point out, as I didn't earlier, that the graylog cpu utilization in the xentop image I up loaded has been fixed so CPU util is much much less now.
However, the CPU utilization of that vm was also at the high levels after a server reboot so dont think its the answer to why all vm's slowly slow down
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What's the hardware behind it by the way?
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My server is HP DL380 G9, CPU 2 x E5-2620 v3 @ 2.40GHz with 4xSSD and 16xHDD 2.5" and 128Gb RAM.
System ( XCP-ng and OS ) is on 4 x SSD RAID 10, DB is on 14 x HDD RAID 10. -
@Gheppy What is free disk space like on this VM?
This is what caused the CPU's in our graylog server to go nuts. It had almost run out of free disk space. The only thing I have done was to increase free disk space by clearing out some of the older logs.
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There is free space, on real disks I have:
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4 x 400Gb SSD = 800Gb RAID 10, on which I have XCP-ng and the rest of the disk is with the first disk of the VM where is the operating system, which has 350 Gb allocated in which I have 2 partitions with 150 Gb SO and 200 Gb SQL log (for some speed). The occupied space being for SO 65Gb and for SQL log of 120Gb.
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14 x 1200Gb = 8.4Tb RAID 10, on which I have the rest of the database divided on 3 virtual disks of 2Tb with soft RAID in the OS ( which is windows ),the configuration is like this because of the XCP-ng limit of 2Tb per vdisk. The database currently has 3.7 Tb.
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@Gheppy If you run top, how is the dom0 CPU load and how is the swap space? If dom0 is saturated it may need more memory allocated to it.
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This is a top img, swap it seems to be ok but memory is 103 Mb free of 7.4Gb.
I will increase the memory for Xen. Thank you
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@tjkreidl
I increased the RAM for Xen to 10Gb and it is much better, maximum 156% on CPU on xentop.
Thank you -
@Gheppy You have to give dom0 enough CPU power for various reaasons: 1) to be able to not be bogged down, itself, 2) to allow VMs to be able to interact with dom0 reasonably fast, 3) to provide enough resources to deal with storage and network I/O. Showing essentially no swap space in use is good!
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Seasons greetings to all,
So the slowness of is creeping back. Still cant find any thing obvious
Latest Xen Top
Due to business pressures we have had to reboot the physical server.
So now have to wait for the issue to re occur.there were 5 more patch's which have been applied.
If anyone has any other suggestion of what to check, specific logs to search etc, etc they would be gratefully received
Kind regards
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Adding @fohdeesha in the loop
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can't say that time from reboot a cause of problem, but sometimes i'm feel something about it. Even ssh connection takes tooooo long, like 10 sec in local network. Same for http speed for small services without any load.
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@Berrick Run iostat and see if anything shows up as slow or saturated with your storage I/O.
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hi Berrick, most of the issues that happen like this is due to IO i believe. I've been using XCP ng for many years and I have about 100 VMs. I love xcp and its the best out there. There are few instance that my VM starts to crawl to be unusable.
- One of the disk fails in the raid and cause my VMs on that particular server to crawl.
- Too little memory provisioned. Heavy usage.
Hope my above helps
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@EddieCh08666741 Indeed. Run top and make sure you have adequate resources allocated for dom0 for both memory and CPU. There should be no swapping to speak of and the CPU should be nowhere close to 100% in use.
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Thanks for all the replies.
I will be checking when the issue starts again in a few weeks and report back.From previous xentop output I don't believe Dom0 is showing high CPU or Memory.
I also dont think there is a problem with the physical disks.
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@Berrick
So its been a while since my last post on this topic but finally I think we have bottomed this issue out!
So the long and the short.
Nothing we tried, checked or diagnostics ran up to this point showed any issue.
Then one Monday morning there was one alert from the iLO about "Corrected Memory Error threshold exceeded"As this server was due a memory upgrade to LV memory soon and we would need to reboot to clear the alert we brought the upgrade forward.
Since the new memory was installed, tempting fate here, it has been OK
Thanks to all that offered advice.
Kind regards
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Oh wow. So something was wrong with the hardware, specifically the memory, and potentially more errors and error correction trying to keep up, slowing down everything. Is it a good recap?
