Cannot boot a new VPS on XenHVM node? We can help you.

As part of our Server Management Services, we assist our customers with several VPS queries.

Today, let us see how we can fix this error quickly.

Are you unable to boot a new VPS on XenHVM node?

 
Usually while booting or starting a new VPS in XenHVM node via SolusVM , users may see certain errors which can happen due to several reasons.

Today, let us discuss about the two reasons that we noticed and it’s resolution provided by our Support Techs.

Cannot boot a new VPS on XenHVM node if the VMID greater than 10000

 
Typical error will look as below on attempt to start VPS from command line.

# xl create -c /home/xen/vm10003/vm10003.cfg
Parsing config from /home/xen/vm10003/vm10003.cfg
WARNING: ignoring “vncviewer” option. Use “-V” option of “xl create” to automatically spawn vncviewer.
WARNING: you seem to be using “kernel” directive to override HVM guest firmware. Ignore that. Use “firmware_override” instead if you really want a non-default firmware
libxl: error: libxl_exec.c:118:libxl_report_child_exitstatus: /etc/xen/scripts/vif-bridge add [12018] exited with error status 1
libxl: error: libxl_device.c:1150:device_hotplug_child_death_cb: script: ip link set vif1541.0-emu name vifvm10003.0-emu failed
libxl: error: libxl_create.c:1384:domcreate_attach_vtpms: unable to add nic devices

Resolution:

• Firstly, connect to the SolusVM Xen slave server via SSH.
• Then, comment out the option no_vif_prefix in configuration file /usr/local/solusvm/data/config.ini and set is as true.

[XEN]
; Set this to true to remove the vifvm prefix from the interface vif names
no_vif_prefix = true

• If the file /usr/local/solusvm/data/config.ini does not exist, create it from /usr/local/solusvm/data/config.ini.example.

# cp /usr/local/solusvm/data/config.ini.example /usr/local/solusvm/data/config.ini

• The new setting will be applied for the new VPSes automatically. For already existing VPS, rewrite configuration file of the VPS by clicking on Rewrite Config icon on the virtual server management page.

If the issue persists on the new server, there is a probability that NetworkManager prevents starting virtual interface.

VPS on SolusVM Xen HVM node does not start

 
Again, on attempt to start VPS from command line you can see the below error:

# xl create -c -V /home/xen/vm101/vm101.cfg

c: error: panic: xc_dom_boot.c:379: xc_dom_gnttab_hvm_seed: failed to add gnttab to physmap [errno=12]
: Internal error
libxl: error: libxl_dom.c:708:libxl__build_dom: xc_dom_gnttab_init failed: Cannot allocate memory

Sometimes, Xen HVM VPS starts but shuts down unexpectedly.

In Xen dmesg logs you can see the following error:

# xl dmesg

(XEN) Failed to shatter gfn 44a75: -12
(XEN) d12124v0 EPT violation 0x59c (–x/rw-) gpa 0x00000044a750d6 mfn 0x644a75 type 0
(XEN) d12124v0 Walking EPT tables for GFN 44a75:
(XEN) d12124v0 epte 9c000019e5d86107
(XEN) d12124v0 epte 9c00000640000bf3
(XEN) d12124v0 — GLA 0xffffb00a430100d6
(XEN) domain_crash called from vmx.c:3385
(XEN) Domain 12124 (vcpu#0) crashed on cpu#10:

It usually occurs if SolusVM sets too low value for shadow_memory.

Resolution:

 
Let us see the steps followed by our Support Techs to resolve it.
 

For an existing VPS

• Firstly, open SolusVM > Virtual Servers > VPS > Custom Config.
• Then, tick the “Enable Custom Config” and “Custom Only” options.
• Copy and paste Live Config to Custom Config field.
• Next, remove the line “shadow_memory”.
• Finally, press Save and Reboot.

For a new VPS

• Firstly, connect to Master server over SSH.
• Access Master database.

# wget https://raw.githubusercontent.com/solusvm-support/helpers/master/solusvmdb.sh && sh solusvmdb.sh

• Finally, Run the query below:

ALTER table xendata modify shadow int(5) NULL;

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Conclusion

In short, today we saw the steps followed by the Support Techs to resolve boot error on VPS.