@olivierlambert Where? How to find it? As you can see, I only have 4 virtual machines on the XCP-ng host.

Hello,
This issue was related to XPC-ng and caused me to delete and recreate and configure one of the most important virtual machines I have. As I said, every virtual machine I create is only 33% complete, and when I try to turn on virtual machines that are already turned off, I get the message "VM state is halted but should be running".
I had to turn the server off and back on to fix the problem. To be honest, I'm afraid to test again to see if the problem is fixed, because I have a VPN server that has a number of users connected to it, and I also have a monitoring server.
If it is a hardware problem, the green lights on the hard drive should change to orange or red, but all the hard drive lights on the server are green. I think the problem is related to the stability of XCP-ng.

I rebooted the server and now I got:

@Pilow
I guess my server using RAID5.
I created a VM with PXE as boot, but it is VM.start: 50%.

@Pilow
Please take a look at these:

[09:08 xcp-ng ~]# df -h
Filesystem      Size  Used Avail Use% Mounted on
devtmpfs        2.8G   20K  2.8G   1% /dev
tmpfs           2.8G  160K  2.8G   1% /dev/shm
tmpfs           2.8G   11M  2.8G   1% /run
tmpfs           2.8G     0  2.8G   0% /sys/fs/cgroup
/dev/sda1        18G  2.0G   15G  12% /
xenstore        2.8G     0  2.8G   0% /var/lib/xenstored
/dev/sda5       3.9G  836M  2.8G  23% /var/log
tmpfs           571M     0  571M   0% /run/user/0
[09:17 xcp-ng ~]# mount | grep -E "(\/var|\/opt)"
xenstore on /var/lib/xenstored type tmpfs (rw,relatime,mode=755)
/dev/sda5 on /var/log type ext3 (rw,relatime)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw,relatime)
[09:18 xcp-ng ~]# dmesg | grep -iE "(error|fail|timeout|scsi|sd|hba)" | tail -20
[81734324.210688] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.217399] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.223994] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.230647] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.237867] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.244529] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.251239] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.257781] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.264466] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.270941] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.277574] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.284149] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.290576] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.297118] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.306270] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.314061] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.322632] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.330717] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.337242] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[81734324.344686] Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
[09:18 xcp-ng ~]# pvs
  PV         VG                                                 Fmt  Attr PSize  PFree  
  /dev/sda3  VG_XenStorage-00f82a18-a9f6-f7bc-9ca1-f42698d46b5f lvm2 a--  95.18g <95.18g
  /dev/sdb   VG_XenStorage-c5129868-a590-68ca-e587-db708ad61f38 lvm2 a--  <3.64t   3.09t
[09:18 xcp-ng ~]# vgs
  VG                                                 #PV #LV #SN Attr   VSize  VFree  
  VG_XenStorage-00f82a18-a9f6-f7bc-9ca1-f42698d46b5f   1   1   0 wz--n- 95.18g <95.18g
  VG_XenStorage-c5129868-a590-68ca-e587-db708ad61f38   1   8   0 wz--n- <3.64t   3.09t
[09:18 xcp-ng ~]# lvs -o lv_name,vg_name,lv_size,lv_attr
  LV                                       VG                                                 LSize    Attr      
  MGT                                      VG_XenStorage-00f82a18-a9f6-f7bc-9ca1-f42698d46b5f    4.00m -wi-a-----
  MGT                                      VG_XenStorage-c5129868-a590-68ca-e587-db708ad61f38    4.00m -wi-a-----
  VHD-1461c885-89c6-4e0e-8ee1-7d5be059f3dc VG_XenStorage-c5129868-a590-68ca-e587-db708ad61f38  <30.07g -wi-------
  VHD-2aaa4501-1c9b-48d6-8532-961ab8a3e627 VG_XenStorage-c5129868-a590-68ca-e587-db708ad61f38  <30.07g -wi-ao----
  VHD-4de5831d-5a4d-4d2d-9f0a-ce4d1c2d8ef5 VG_XenStorage-c5129868-a590-68ca-e587-db708ad61f38  100.20g -wi-a-----
  VHD-6b1ea821-d677-4426-99e0-43314ef3c536 VG_XenStorage-c5129868-a590-68ca-e587-db708ad61f38 <250.50g -wi-ao----
  VHD-6c08ae7f-71a7-4f97-a553-3c067dbbe243 VG_XenStorage-c5129868-a590-68ca-e587-db708ad61f38  <50.11g -wi-a-----
  VHD-bc8dd3e4-ea0e-4006-a918-817b18d65456 VG_XenStorage-c5129868-a590-68ca-e587-db708ad61f38  <50.11g -wi-ao----
  VHD-ccaaabb0-b5ae-4e29-ab8d-c895af000550 VG_XenStorage-c5129868-a590-68ca-e587-db708ad61f38  <50.11g -wi-a-----
[09:18 xcp-ng ~]# lvdisplay /dev/VG_XenStorage-c5129868-a590-68ca-e587-db708ad61f38/VHD-ccaaabb0-b5ae-4e29-ab8d-c895af000550
  --- Logical volume ---
  LV Path                /dev/VG_XenStorage-c5129868-a590-68ca-e587-db708ad61f38/VHD-ccaaabb0-b5ae-4e29-ab8d-c895af000550
  LV Name                VHD-ccaaabb0-b5ae-4e29-ab8d-c895af000550
  VG Name                VG_XenStorage-c5129868-a590-68ca-e587-db708ad61f38
  LV UUID                TggCle-7H7d-BN1o-KU5U-8oME-lckS-z0puvZ
  LV Write Access        read/write
  LV Creation host, time xcp-ng, 2023-07-11 14:19:40 +0330
  LV Status              available
  # open                 0
  LV Size                <50.11 GiB
  Current LE             12827
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:2
  

I don't know what happened.

@Pilow
Doesn't work. It just show VM.start: 33%
I'm afraid to restart the server too because the XO will not run also.

@Pilow
I just have one host and I use local storage.

[09:27 xcp-ng ~]# xl list
Name                                        ID   Mem VCPUs	State	Time(s)
Domain-0                                     0  5936    16     r-----  18024910.4
XO                                          72  4096     2     -b----  8899359.6
Grafana                                    114 16383     1     --psr-  2983554.9
Tor                                        156  2039     1     --p---       0.0
[09:28 xcp-ng ~]# xenops-cli list
Name                                         ID   Mem   VCPUs     State   Time(s)
Tor                                          -    2048  4         Paused  
Grafana                                      -    16384 4         Paused  
XO                                           72   4096  2         Running 

@Pilow
I see :

Headers Timeout Error

Nothing in the HEALTH and I use Xen Orchestra, commit 83a69 and:

[09:04 xcp-ng ~]# cat /etc/redhat-release 
XCP-ng release 8.2.1 (xenenterprise)

Hello,
Every virtual machine I restart doesn't boot. It just show VM.start: 33%. I did:
# xe-toolstack-restart
# service xapi restart

But, problem exit. All my servers went down.

What should I do?

Thank you.