Oracle Cloud – Logging into your instance via SSH

In my last post I showed how easily we could create a new instance, after the machine has initialised you should be able to login using the SSH key

We can find out the public IP address for our instance from the Services dashboard and drilling into the Service by clicking the name.

ssh1.png

ssh2.png

note – I’ve obscured my Public IP here for obvious reasons.

So now that I know the Public IP, I can try and connect via SSH using the private key I created in the earlier post.

[jes@mac oracle-cloud]$ ssh -i oracle_cloud_rsa root@<my.public.ip.here>
Permission denied (publickey,gssapi-keyex,gssapi-with-mic).

I use the -i parameter to SSH to use my private key and pass my IP address, but it doesn’t work. Hmmm, after quickly checking the docs I see that the SSH key doesn’t correspond to the root user but rather the ‘opc‘ user (where presumably ‘opc‘ represents Oracle Public Cloud).

So let’s try again, using the opc user this time:

[jes@mac oracle-cloud]$ ssh -i oracle_cloud_rsa opc@<my.public.ip.here>
[opc@DEMO ~]$

success (and a very underwhelming login message)! We’re now SSH’d into our Oracle DBaaS service.

So let’s run a few basic system commands what we have here:

[opc@DEMO ~]$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/xvdb3  25G   16G  7.8G 68% /
tmpfs      3.6G  2.0G  1.6G 56% /dev/shm
/dev/xvdb1 477M  148M  300M 34% /boot
/dev/xvdc1  30G  8.3G   20G 30% /u01
/dev/mapper/dataVolGroup-lvol0
 99G 4.0G 90G 5% /u02
/dev/mapper/fraVolGroup-lvol0
 9.8G 131M 9.1G 2% /u03
/dev/mapper/redoVolGroup-lvol0
 9.8G 3.1G 6.2G 33% /u04

So you can see the standard installation creates a few Oracle specific mount points (/u01, /u02, /u03 and /u04).

My first observation was that I would have preferred /home to be on a seperate mount as I’m always slightly paranoid about the root filesystem filling up (as most verteran Linux / Unix admins are). Personally I think 7.8Gb free in the root filesystem is just a little too low for a production system and I’d like to see

  • An option for putting /home on a seperate mount
  • Ability to tweak the default sizes for / and /home

(just as Amazon AWS does)

Ok, so that’s the disk, what about the CPU? Running the ‘top’ command shows me the following output.

top.png

 

Remember I opted for 1 OCPU, but that each OCPU gives me 2 threads (vCPU’s), that’s why I see Cpu0 and Cpu1 in the output (if I’d gone for 4 OCPU’s then I’d see 8 CPU’s listed in top).

I can see what type of CPU’s they are reported to the OS by querying /proc/cpuinfo (remember this is a virtualised environment so the information might not be strictly ‘correct’, but should be a good indication).

[opc@DEMO ~]$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 62
model name : Intel(R) Xeon(R) CPU E5-2690 v2 @ 3.00GHz
stepping : 4
microcode : 0x428
cpu MHz : 2992.846
cache size : 25600 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 13
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 eagerfpu pni pclmulqdq ssse3 cx16 pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm xsaveopt fsgsbase smep erms
bogomips : 5985.69
clflush size : 64
cache_alignment : 64
address sizes : 46 bits physical, 48 bits virtual
power management:
...extra duplicate output for processor 1 omitted...

So we can see we have 2 Intel Xeon E5-2690 v2 CPU’s running at 3.00Ghz (or at least reporting that they are).

Not much else to say here, once you’ve SSH’d into the machine it’s just like any other machine. In the next post we’ll cover connecting to the Oracle DB.

 

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