Root Access

Aibobot

00:23

@djsmiley2k-CoW dead dead or mostly dead?

And doth thou hast backups?

bertieb

01:46

Can someone remind me of the right incantation to set up an ssh tunnel to an a machine on another network

(for the purposes of VNC tunnelling)

can I do ssh → gateway openssh (A) →→ VNC (B) ?

or do I have to a do a 'jump' ssh to the machine (B) running vnc

bwDraco - Reinstate Monica

You can set it up on the same machines. No additional jump server is needed. (That's how I set up RDP over SSH on Astaroth).

bertieb

Yea but how

I can never remember the right incantation of -R or -L

and pretty much just cycle through likely options until something works

I read an article but I think I came away knowing less that I did when I started reading

it's late and I have had an attack of the stupids

2

but want to get up and running while I sleep

bwDraco - Reinstate Monica

It's kinda hard for me to explain...

bertieb

Hmm

I thought I had it

but no

ssh -R localport:VNC_IP:VNC_PORT ssh_gateway

is what I thought

bwDraco - Reinstate Monica

On the server side, forward localhost:5900. On the client side, have it go to a local port of your choice (it's best to choose a high port, like 55900).

bertieb

01:54

Gods I've done this dozens of times over the years

I should really learn and remember how to do it properly

but I VNC so rarely these days

@bwDraco-ReinstateMonica I know what I'm trying to do, just not haow to do it :P

bwDraco - Reinstate Monica

You'll need to make sure there's a port forwarded to port 22 on your machine through your router.

Journeyman Geek

I've mostly done this on putty ._.

bertieb

@bwDraco-ReinstateMonica Er

this is why I asked about the ssh gateway

because guess what machine port 22 is forwarded to here

bwDraco - Reinstate Monica

-L 55900:localhost:5900

bertieb

and I don't want to change port forwardings when I'm not physically present in case it goes, uh, tents-up

bwDraco - Reinstate Monica

01:57

Then point your VNC client to localhost:55900 on the client machine.

bertieb

close

but good enough

Journeyman Geek

@bertieb g I'm thinking of setting up nebula for stuff like that ;)

bertieb

@JourneymanGeek nebula?

@bwDraco-ReinstateMonica I dunno why it would be -L but it is

Journeyman Geek

@bertieb newfangled mesh VPN by slack

bwDraco - Reinstate Monica

@bertieb Forward to local port.

bertieb

01:58

@JourneymanGeek Ah

@bwDraco-ReinstateMonica Yes

But why

(in my head, the logic goes) I am connecting to a remote machine's port

so I need -R

Journeyman Geek

@bertieb if memory serves I run a dynamic destination port on my ssh gateway, use the tunnel as a proxy and stuff 'just' works

bertieb

and I seem to remember being thrown by this on more than one occasion

bwDraco - Reinstate Monica

The tunneled connection is accessible to the local machine's port 55900. The SSH server connects to localhost:5900 (the server's own VNC port) and passes it through the SSH connection.

bertieb

@JourneymanGeek Yea, I'm currently using a dynamic port forwarding to see the internal router page

@bwDraco-ReinstateMonica Yes, but in this case it isn't the server's own VNC port

the server is not running VNC

Journeyman Geek

@bertieb noooo on anything

bertieb

02:01

client → ssh machine (A) → VNC machine (B)

bwDraco - Reinstate Monica

Then change the localhost in -L 55900:localhost:5900 to the proper host machine in the server-side network.

bertieb

@bwDraco-ReinstateMonica Yes, I've already done that

and it works

I just want to know why it uses the -L notation

bwDraco - Reinstate Monica

Which is precisely what you're trying to achieve.

bertieb

as I said

bwDraco - Reinstate Monica

-L means "forward to local port on the client".

bertieb

02:02

yes

perhaps I am being unclear here

(likely)

what is being forwarded to the local port?

and forwarding suggests a direction; whereas I am able to connect to the VNC server on machine 'B'

bwDraco - Reinstate Monica

The specified port on the specified host, from the perspective of the server.

bertieb

which is 'backwards' from my machine (client), if something is being forwarded to it

(I'm not being deliberately obtuse here to make a point, I just find the terminology backwards from the perspective I would expect)

if something says "this forward to a local port on the machine running the ssh command", I would expect remote things to be able to access the client machine's port

not being able to access a remote machine's port via a port on the client

bwDraco - Reinstate Monica

-L 55900:localhost:5900 means you're forwarding localhost:5900 as seen by the server to the client's port 55900, passing it through the SSH connection.

bertieb

Okay, that kinda makes sense!

my second question is: why does nowhere else explain it like that?

or am I the only person in the world (plus or minus one or two) that finds the terminology confusing?

bwDraco - Reinstate Monica

Yeah, I found it confusing, too.

bertieb

02:10

if I am that's fine, it's a learning experience, I can live with that

ah thank dogs

it's not just me

I appreciate your patience in explaining it

bwDraco - Reinstate Monica

Because the SSH server can forward any port on any host the server sees to the client. It's not limited to ports on the server itself.

Hence, if you're forwarding a port on the same server, localhost needs to be specified.

bertieb

Yeah, I get that bit too

it just... I dunno

nowhere explains it in an idiotproof way

bwDraco - Reinstate Monica

I could conceivably forward <network printer IP>:9100 on Astaroth to port 59100 on my laptop, and point the print driver to port 59100 on the local machine to send print jobs to my printer at home.

djsmiley2k - CoW

12:35

> 3. The Crash Mats - NOW Thats what I call Crash Mats 69 (15.2%) (missing tracks, artist, tracks, ...) (CD, 2016, XW, Horn & Hoof Records, HH-0011)

I don't even...

> 1656

mp3s to go... :D

@bertieb how long ago did you tell me about beets? XD

> Dec 22 12:40:58 MushaV3 smartd[4411]: Device: /dev/sda [SAT], SMART Usage Attribute: 190 Airflow_Temperature_Cel changed from 78 to 77
Dec 22 12:40:58 MushaV3 smartd[4411]: Device: /dev/sda [SAT], SMART Usage Attribute: 194 Temperature_Celsius changed from 22 to 23

errr

Why report one in C and the other in F?! :D

bertieb

12:58

@djsmiley2k-CoW Something something galaxy far far away

djsmiley2k - CoW

13:17

:D

djsmiley2k - CoW

13:41

hm,mmmm

is logrotate rotating my logs I wonder

> -rw------- 1 root root 9.7K Dec 22 03:10 messages-20191222.gz

seems so

djsmiley2k - CoW

14:35

@Aibobot one is dead dead (as in constant IO errors, but it at least responds to commands, and I managed to badblocks write it... so it's 'empty' of data

the other is just occasionally reporting ECC corrections and suchj

> pastebin.com/uCrWpKZA

wait

what

> MushaV3 /home/tim/server/media/music # zgrep SMART /var/log/messages-* | grep ECC
/var/log/messages-20191201.gz:Nov 24 04:40:58 MushaV3 smartd[4411]: Device: /dev/sdb [SAT], SMART Usage Attribute: 195 Hardware_ECC_Recovered changed from 23 to 24
/var/log/messages-20191201.gz:Nov 24 12:10:58 MushaV3 smartd[4411]: Device: /dev/sdb [SAT], SMART Usage Attribute: 195 Hardware_ECC_Recovered changed from 24 to 23
/var/log/messages-20191201.gz:Nov 24 21:10:58 MushaV3 smartd[4411]: Device: /dev/sdb [SAT], SMART Usage Attribute: 195 Hardware_ECC_Recovered changed from 23 to 24

The values going UP and DOWN?!

Journeyman Geek

15:30

16

Q: Should I be concerned about a high SMART Hardware_ECC_Recovered value?

I got such a message in /var/log/messages: Jun 25 06:29:27 server.ru smartd[4477]: Device: /dev/sda, SMART Usage Attribute: 195 Hardware_ECC_Recovered changed from 46 to 47 #smartctl -a /dev/sda: smartctl version 5.38 [i686-redhat-linux-gnu] Copyright (C) 2002-8 Bruce Allen Home page is htt...

specifically

4

A: Should I be concerned about a high SMART Hardware_ECC_Recovered value?

First, lower values are worse for SMART, not higher values (notice how the threshold column is always lower than the current value). So, a value increasing is no cause for worry. (This rule does not apply to the raw values, however.) SMART values tend to oscillate a bit (yours might be in the ed...

and

6

A: Should I be concerned about a high SMART Hardware_ECC_Recovered value?

A high value for this attribute is actually pretty good: Hardware ECC Recovered S.M.A.R.T. parameter indicates time between ECC-corrected errors. https://kb.acronis.com/content/9131

djsmiley2k - CoW

16:53

ah interesting

it's the average time between corrections

That Brazilian Guy

Hello there

djsmiley2k - CoW

o/

That Brazilian Guy

Is it me or is this place empty?

Is it the holidays? Or the SEpocalipse?

I haven't been here in...

checks chat history

Okay, you can't search for "*" said by [user] =/

Canadian Luke REINSTATE MONICA

@djsmiley2k-CoW No, it wasn't. Even though the Debian package says it was....

bertieb

17:47

@ThatBrazilianGuy I think it works if you search for space

or maybe not

I was sure I did this a while back when people were asking when I joined chat

Canadian Luke REINSTATE MONICA

@bertieb You could have asked here anytime :) I could have explained it too

We use it almost every day at my work...

bertieb

@CanadianLukeREINSTATEMONICA I did, last night ;-P

the other times I've done it I've figured it out eventually (well, 50/50 chance of picking the correct one, right?)

Canadian Luke REINSTATE MONICA

Well, fail... I wasn't here to explain it in my blog-format :P

jk

But yea, with SSH, you can do lots of cool stuff

bertieb

but this time I was sufficiently tired ~~and emotional~~ and grumpy that I rant-asked about the meaning

Oh yea

I am happy to do "An Interview with an Idiot" if that would help create the blog post? ;-P

Canadian Luke REINSTATE MONICA

X11 forwarding - run server programs and have the window appear on your local system
VPN - Create a tunnel interface, and route traffic through it (not just ports!)
SSH-Agent Forwarding - Use one key, and pass that key automatically from SSH to SSH to SSH session

@bertieb Sure! Come up with some questions, and I'll do my best

bertieb

17:58

@CanadianLukeREINSTATEMONICA Cool cool, I might wait until I'm less grumpy

or more grumpy

I'm not sure which would work better

I'm just having one of those days

except it's been more than a day

I think my IQ has dived about twenty points this year

plus or minus 20

djsmiley2k - CoW

18:24

:D

"Explain like my IQ is $IQ-20."

That Brazilian Guy

18:37

@bertieb Found this: chat.stackexchange.com/users/57459/…

So I haven't been here since Nov 6 and before that Sept 4

Canadian Luke REINSTATE MONICA

18:55

@bertieb Anytime!

Journeyman Geek

23:10

@ThatBrazilianGuy actually I think more the latter. Riot has been quietish too

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