Symptoms
ESXi host is being prepared for NSX-T.
Workloads (Virtual Machines) are running on the host during host preparation.
ESXi host may experience a Purple Screen of Death (PSOD) with backtrace similar to:ip_init: failed to allocate flowtableCode start: 0x42000f400000 VMK uptime: 87:01:14:56.2830x4539b829b180:[0x42000f4ff0a3]PanicvPanicInt@vmkernel#nover+0x327 stack: 0x4539b829b2880x4539b829b250:[0x42000f4ff90a]Panic_vPanic@vmkernel#nover+0x23 stack: 0x41ffd38142980x4539b829b270:[0x42000f5165aa]vmk_vPanic@vmkernel#nover+0xf stack: 0x80000x4539b829b280:[0x42001076ff3b]panic@(tcpip4)#<None>+0x4c stack: 0x4539b829b2e00x4539b829b2e0:[0x4200107c3669]ip_init@(tcpip4)#<None>+0x686 stack: 0x41ffd3802f600x4539b829b320:[0x42001078d5da]domain_init@(tcpip4)#<None>+0x2f stack: 0x431a529010800x4539b829b340:[0x42001077462e]vmk_net_instance_init@(tcpip4)#<None>+0x463 stack: 0x2af8000000800x4539b829b3f0:[0x4200107652f6]Tcpip_InitializeStackInstance@(tcpip4)#<None>+0x217 stack: 0x20x4539b829b4b0:[0x42000f6be9df]Net_TcpipCreateStackInstance@vmkernel#nover+0xe4 stack: 0x30x4539b829b500:[0x42000f706e53]NetVsi_TcpipCreateNetinstanceSet@vmkernel#nover+0x184 stack: 0x3b0x4539b829b5a0:[0x42000f4023dd]VSI_SetInfo@vmkernel#nover+0x2ca stack: 0x4539b829b6a00x4539b829b620:[0x42000f92a702]UW64VMKSyscallUnpackVSI_Set@vmkernel#nover+0x1eb stack: 0x4539b829b8e00x4539b829bee0:[0x42000f8b408a]User_UWVMK64SyscallHandler@vmkernel#nover+0x183 stack: 0xd783bed685fd8450x4539b829bf40:[0x42000f54b4b8]SyscallUWVMK64@vmkernel#nover+0x90 stack: 0x0
Cause
The issue is from not having enough TCP/IP heap space. If the ESXi host is running low on memory. It can't allocate the heap space needed to become an NSX Host Transport Node. This can lead the kernel to exhaust its memory completely. That results in the ESXi host crashing with a Purple Screen of Death (PSOD).
Resolution
The issue with ESXi TCP/IP heap is fixed in 7.0 u3o.
Workaround
Reduce memory consumption on the ESXi host (e.g. by managing number of VMs on the host, or putting the host to Maintenance Mode).
If the host has already experienced a PSOD, NSX preparation is expected to complete after the reboot.
