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Aug 2021

Hi All,

I am new to MongoDB. What I do I follow the installation guide to install MongoDB

Using tarball. My OS is Oracle Linux 8.4

After completed installation

I started
mongod --dbpath /var/lib/mongo --logpath /var/log/mongodb/mongod.log

and always got “illegal instruction (core dumped)”

I dont know how to check it, and there is no log too and not sure why coredump.

Can you advise where to check and how to fix it?

Appreciated . Thanks

May be it is a permissions issue
mongodb is unable to access dbpath & logpath directories
Does the owner of mongod have read/write privs on these dirs

For test purpse you can change db & log path to some other dir like your home dir and check

Welcome to the MongoDB Community Forums @Dinh_Hoang !

An illegal instruction error suggests that you are running a binary which is not supported by your CPU.

Can you confirm:

  • Your CPU details
  • Version of MongoDB server you have installed

Regards,
Stennie

Thanks for reply.

I change dir again and start it but it is still the same

[mongod@localhost ~]$ ls -lrt total 0 drwxrwxr-x. 2 mongod mongod 6 Aug 21 09:03 mongo drwxrwxr-x. 3 mongod mongod 21 Aug 21 09:03 log [mongod@localhost ~]$ ls -lrt /home/mongod/log/mongodb/ total 0 [mongod@localhost ~]$ ls -lrt /home/mongod/mongo total 0 [mongod@localhost ~]$ mongod --dbpath /home/mongod/mongo --logpath /home/mongod/log/mongodb/mongod.log Illegal instruction (core dumped) [mongod@localhost ~]$

I am using Oracle Linux 8.4 on Virtual Box, It is x86-64 bits

I downloaded Linux redhat/CentOS 8.0. Is it correct bin?

Thanks for your help

Just add in more detail for OS

Static hostname: localhost.localdomain Icon name: computer-vm Chassis: vm Machine ID: ff3df1686a26409199f9686b0646ca6a Boot ID: 88496d361dad421e9d1e11113f9559f6 Virtualization: oracle Operating System: Oracle Linux Server 8.4 CPE OS Name: cpe:/o:oracle:linux:8:4:server Kernel: Linux 5.4.17-2102.201.3.el8uek.x86_64 Architecture: x86-64

Hi All,

I downloaded 4.4 and it works, I am not sure why latest version 5.0.2 did not work for Oracle Linux 8.4

Have a nice day!

Thanks

Hi Chris and Stennie,

Here is my info

processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 142 model name : Intel(R) Core(TM) i5-8350U CPU @ 1.70GHz stepping : 10 microcode : 0xffffffff cpu MHz : 1895.999 cache size : 6144 KB physical id : 0 siblings : 4 core id : 0 cpu cores : 4 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 22 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx rdtscp lm constant_tsc rep_good nopl xtopology nonstop_tsc cpuid tsc_known_freq pni ssse3 cx16 pcid sse4_1 sse4_2 hypervisor lahf_lm invpcid_single pti fsgsbase invpcid md_clear flush_l1d arch_capabilities bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit bogomips : 3791.99 clflush size : 64 cache_alignment : 64 address sizes : 39 bits physical, 48 bits virtual power management:

There is 4 cores , So it should be a “Sandy Bridge* or later Core processor”
therefore I am confusing why It did not work for MongoDB 5

Thanks

I found the note

MongoDB only supports Oracle Linux running the Red Hat Compatible Kernel (RHCK). MongoDB does not support the Unbreakable Enterprise Kernel (UEK).

It could be I am using kernel UEK, but how to check and confirm it?

#uname -a
Linux localhost.localdomain 5.4.17-2102.201.3.el8uek.x86_64 #2 SMP Fri Apr 23 09:05:57 PDT 2021 x86_64 x86_64 x86_64 GNU/Linux

It is EUK kernel but it works for 4.4 not 5.0.2, It is strange

Hi @Dinh_Hoang,

Your Core i5-8350U CPU looks like it should have the right feature support, but your /proc/cpuinfo output is missing AVX extensions.

Can you confirm:

  • version of VirtualBox used
  • host O/S

It looks like there are a few conditions for AVX support in VirtualBox:

Regards,
Stennie

Hi Stennie,

My Virtual box version is 6.1.26 (latest version) and on Win10 OS.

I tried 5.0.2 on Red hat OS 7.8, it works perfectly. Therefore it could be something with Oracle Linux kernel

Thanks
Dinh