Troubleshooting Controll Domain High Memory Warning

stevewest15

Hi,

I'm running an older version of XCP-ng (v 8.0.1) which I'm trying to figure out what is causing the Dom0 high memory usage:

Checking dmesg shows tons of the following messages but not sure what they mean:

[39998832.644126] block tdx: sector-size: 512/512 capacity: 167772160
[39998833.318498] block tdy: sector-size: 512/512 capacity: 209715200
[39998844.591972] block tdz: sector-size: 512/512 capacity: 25165824
[39998844.612378] block tdab: sector-size: 512/512 capacity: 209715200
[39998844.665207] block tdaa: sector-size: 512/512 capacity: 209715200
[39998844.825059] block tdac: sector-size: 512/512 capacity: 167772160
[39998847.072573] block tdad: sector-size: 512/512 capacity: 25165824
[39998847.342641] block tdae: sector-size: 512/512 capacity: 209715200
[39998847.382385] block tdaf: sector-size: 512/512 capacity: 209715200
[39998848.091827] block tdag: sector-size: 512/512 capacity: 167772160
[39999260.166570] block tdr: sector-size: 512/512 capacity: 62914560
[39999262.000706] block tds: sector-size: 512/512 capacity: 62914560
[39999277.792759] block tds: sector-size: 512/512 capacity: 8388608
[39999277.793975] block tdt: sector-size: 512/512 capacity: 31457280
[39999277.800976] block tdr: sector-size: 512/512 capacity: 104857600
[39999277.839117] block tdu: sector-size: 512/512 capacity: 419430400
[39999278.241445] block tdv: sector-size: 512/512 capacity: 629145600
[39999280.463193] block tdw: sector-size: 512/512 capacity: 31457280
[39999280.546328] block tdx: sector-size: 512/512 capacity: 104857600
[39999280.684838] block tdy: sector-size: 512/512 capacity: 8388608
[39999280.733995] block tdz: sector-size: 512/512 capacity: 419430400
[39999281.088353] block tdaa: sector-size: 512/512 capacity: 629145600

Any recommendations on what to check before I do a full restart of the server?

Thank You,

SW

olivierlambert

Hi!

XCP-ng 8.0 isn't security safe nor supported since then. I will strongly suggest to upgrade to 8.2.1 with all patches
Are you using AD integration with XCP-ng Center? Note that XCP-ng Center is NOT officially supported too, so if you use AD feature/integration, then you are on your own (and it seems to have memory leaks from your screenshot)
Sector size/capacity isn't a problem

stevewest15

@olivierlambert Thank You Oliver! I've been meaning to move these 2 VMs to newer servers running latest XCP-ng. The issue in trying to move them is the migration takes so long as the VMs are very large.

Any recommendations on how best to move large VMs that use a mix of local and network storage to a new XCP-ng?

olivierlambert

Yes: for very large VMs, I'm using the "warm migration trick". See this post: https://xcp-ng.org/forum/post/50397

tjkreidl

@stevewest15 I would also increase your dom0 memory, 16 GB is already pretty much all being used and for migrating VMs, you need memory. Some of the resources are used for dealing with storage, whoch requires such resources. If the migration is slow, run iostat and see what resources are being used; there may be a storage bottleneck, as well.