WebDevHobo's questions

I created a ping check on pacemaker, like so:

pcs resource create ping ocf:pacemaker:ping dampen=5s multiplier=1000 host_list=127.0.0.1 clone

Used something other than 127.0.0.1 of course.

Here's the source code: https://github.com/ClusterLabs/pacemaker/blob/master/extra/resources/ping

The ping check foresees an rc code of 0, 1, and any other.

Wanting to see warning and errors, I enabled debug:

pcs resource update ping debug=1

However, instead of logging to /var/log/pacemaker.log, these messages are logged to /var/log/syslog.

Articles like this are just descriptors: https://support.sciencelogic.com/s/article/3961

And this is outdated: http://www.beekhof.net/blog/2013/pacemaker-logging

There doesn't seem to be a way to set this. What am I missing?

EDIT: Most guides I'm finding on this assume CentOs.

On Ubuntu, it seems the pacemaker sysconfig it located here:/etc/default/pacemaker

I read this page and the next: https://clusterlabs.org/pacemaker/doc/deprecated/en-US/Pacemaker/1.1/html/Pacemaker_Explained/_moving_resources_due_to_connectivity_changes.html

And it explains how to set up a ping that you can link to the allocation of a resource.

While this works, if I have more than 1 URL or more than 1 ping check, how can I know which one is failing?

It seems this isn't logged anywhere if it occurs. It just occurs and pacemaker makes a decision...

Reading this source code: https://github.com/ClusterLabs/pacemaker/blob/master/extra/resources/ping

It seems a debug environment variable needs to be enabled. I'd rather not do this, assuming I have to restart pacemaker for it and thus messing up allocations, plus whatever amount of extra logs will now be taking up disk space.

Is there a way to just only log a single line if a ping failed, saying only that, and affecting nothing else?

I want to set up the configuration for Docker as such that, on boot, it does not automatically start the containers.

I've read about disabling the service with systemctl, which would required enabling it manually on next boot.

That being said, I would prefer it if I could configure the systemd service for Docker to wait for the presence of a certain file, in a certain location.

Once the file appears, it can start. And then I just remove it again. This means not having to set the service to disabled every time and potentially entering the wrong command and shutting it back down.

I've google for this, but can't find it.

Things like Wants= and Required= in the Unit file seem to only accept other services and not file locations.

How could this be done?

For a specific user or list of specific users, I want to make it so they are not even asked for a password but just directly refused.

Although this is after I've allowed them 1 specif command. so the sudoers file would look something like this(example):

testuser ALL = (root) NOPASSWD:NOEXEC: /bin/ls, <REFUSE_EVERYTHING_ELSE_WITHOUT_ASKING_FOR_PASSWORD>

Is this at all possible? Basically, what I want to achieve can be written as:

Allow this 1 command listed in the custom sudoers file, refuse everything else without even asking for a password, if it is this particular user.

Is that possible?

I've gone over this entire page: https://www.sudo.ws/man/1.8.15/sudoers.man.html

And haven't found it. It's just the password asking part. I want that gone. Everything else in terms of properly checking permission, I want that to stay.

Is that possible?

EDIT: The solution was something like this:

##
# User alias specification (Example user, must actually exist)
##
User_Alias      Defaults:TEST_USER = test_user

##
# Cmnd alias specification (Example command, multiple wildcards possible)
##
Cmnd_Alias      TEST_CMD = /bin/ls */home/test_user/

# Don't ask for password on this particular user, just apply the rules.
Defaults:TEST_USER !authenticate

TEST_USER ALL = (root) NOPASSWD:NOEXEC: TEST_CMD

I'm just gonna add here: I read the comment on how this setting would allow an attacker to determine which user can execute sudo and which cannot, and that sounds like the attacker is already at the point where they're in my system and able to jump between accounts. Sounds like they got some kind of elevated access if they're at that point. That sounds worse than 1 limited account being compromised, it sounds like they can access all accounts at this point.

Perhaps I'll realize it later, and be all "oh dammit, that's right" but I don't see it right now. I would honestly prefer it be explained. Should I make a separate question for it? Googling this particular option does no yield many results, it seems relatively unknown.

That being said, this particular situation I created is for a user that doesn't have a password at all. So I think an attacker in that case might try a password a few times, maybe a purpose-crafted string even, and then conclude "oh this user doesn't have a password I can't do anything with this user" and move on. Just the same as with disabling authentication. At least now they can't enter a purpose crafted string at all.

Is that horribly naive?

2 machines are mounting the same NFS folder(which is on a single 3rd machine).

Files get uploaded from either client server to this mount, usually in chunks. Server A might handle a chunk, then server B the next, all with start and end points defined so it all ads up in the end.

Still, there's been a few instances where if you run md5sum from serverA, you get a different result than with serverB.

Though in reality, the file is on the NFS server and there should be only 1 version pushed to all clients, far as I'm aware.

And it's not fixing itself over time.

I'm currently assuming this is a race condition, related to the chunks not being added in order and NFS caching, you might get one of the servers thinking the file is at a certain length while it isn't, causing a lot of 0000 0000 padding to be added.

So, how come this is happening? Is there a mount setting I need to use to prevent this? Is there a way to tell the NFS server to re-sync the file to all clients?

And just in general, how should this be dealt with?

EDIT: Mounting options on the clients:

machine1:~$ nfsstat -m
/mnt/dirA from <SERVER_IP>:/dirA
 Flags: rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP>

/mnt/dirB from <SERVER_IP>:/dirB
 Flags: rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP>

machine1:~$ cat /proc/mounts | grep <SERVER_IP>
<SERVER_IP>:/dirA /mnt/dirA nfs4 rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP> 0 0
<SERVER_IP>:/dirB /mnt/dirB nfs4 rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP> 0 0


machine2:~$ nfsstat -m
/mnt/dirA from <SERVER_IP>:/dirA
 Flags: rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP>

/mnt/dirB from <SERVER_IP>:/dirB
 Flags: rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP>

<SERVER_IP>:/dirA /mnt/dirA nfs4 rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP> 0 0
<SERVER_IP>:/dirB /mnt/dirB nfs4 rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP> 0 0

EDIT2: The machines are both Ubuntu 18.04, fresh install, the md5sum tool is version 8.28 on both machines.

EDIT3:

I found this note that I kept on the files. I performed an xxd to get the hexdump, from both machines, from the mount to the local filesystem of the machines. As to be certain it was captured from the point of view of the individual machines. As you can see, according to machine01, there's empty padding in the file, but not according to machine02.

This is the result:

root@machine01:/home/kdguser# grep -C 5 '2ddd5000' output01
2ddd4fb0: 0a78 95ff c53e e2c4 f79a db05 0a59 d7d1  .x...>.......Y..
2ddd4fc0: 85a8 1192 26a6 a25a d741 db3c a61f e72e  ....&..Z.A.<....
2ddd4fd0: 4d0b 97b6 93cc 7845 6ef4 0cca f9aa 9390  M.....xEn.......
2ddd4fe0: 9f00 bacd 707f 2398 f419 e49e 8073 67fb  ....p.#......sg.
2ddd4ff0: 89f5 9450 99f5 808f 4b21 3154 f97f 1271  ...P....K!1T...q
2ddd5000: 0000 0000 0000 0000 0000 0000 0000 0000  ................
2ddd5010: 0000 0000 0000 0000 0000 0000 0000 0000  ................
2ddd5020: 0000 0000 0000 0000 0000 0000 0000 0000  ................
2ddd5030: 0000 0000 0000 0000 0000 0000 0000 0000  ................
2ddd5040: 0000 0000 0000 0000 0000 0000 0000 0000  ................
2ddd5050: ba34 fb76 5af3 69d2 9af0 4711 8a0c eae8  .4.vZ.i...G.....

root@machine02:/home/kdguser# grep -C 5 '2ddd5000' output02
2ddd4fb0: 0a78 95ff c53e e2c4 f79a db05 0a59 d7d1  .x...>.......Y..
2ddd4fc0: 85a8 1192 26a6 a25a d741 db3c a61f e72e  ....&..Z.A.<....
2ddd4fd0: 4d0b 97b6 93cc 7845 6ef4 0cca f9aa 9390  M.....xEn.......
2ddd4fe0: 9f00 bacd 707f 2398 f419 e49e 8073 67fb  ....p.#......sg.
2ddd4ff0: 89f5 9450 99f5 808f 4b21 3154 f97f 1271  ...P....K!1T...q
2ddd5000: c969 a259 431e 2a17 12b4 8365 07cb 5e56  .i.YC.*....e..^V
2ddd5010: fa61 327f eb63 1b13 bc30 eb4b c8f0 af14  .a2..c...0.K....
2ddd5020: 6ebe 3f79 9012 7ece 1662 e104 be19 b249  n.?y..~..b.....I
2ddd5030: 9b9c f61d 180b e92a b93b 9980 aba4 ba41  .......*.;.....A
2ddd5040: 0929 fece fc8a 5309 3883 2562 fe2a 459a  .)....S.8.%b.*E.
2ddd5050: ba34 fb76 5af3 69d2 9af0 4711 8a0c eae8  .4.vZ.i...G.....

While the actual file is the one as seen from machine02. Yet machine01 is showing something else.

EDIT4: Just to be clear, the length of the files is identical, the md5 is different on each client.

My setup:

3 machines, 2 client, 1 server. The server is redhat 7.6, the clients are ubuntu server 18.04.2.

The mount is a few dozen TB, the files placed on the clients are a few 100Gigs each.

The behavior I'm seeing is as follows:

A file gets placed on machine1. Another service then sees it appear on machine2 and tries to append something to it. However, the file on machine2 is not yet complete and this fails.

So there's some sort of latency going on there and I wonder how I should deal with that.

I'm getting the following output when checking the configuration of the mounts(anonymized):

machine1:~$ nfsstat -m
/mnt/dirA from <SERVER_IP>:/dirA
 Flags: rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP>

/mnt/dirB from <SERVER_IP>:/dirB
 Flags: rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP>

machine1:~$ cat /proc/mounts | grep <SERVER_IP>
<SERVER_IP>:/dirA /mnt/dirA nfs4 rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP> 0 0
<SERVER_IP>:/dirB /mnt/dirB nfs4 rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP> 0 0



machine2:~$ nfsstat -m
/mnt/dirA from <SERVER_IP>:/dirA
 Flags: rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP>

/mnt/dirB from <SERVER_IP>:/dirB
 Flags: rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP>

<SERVER_IP>:/dirA /mnt/dirA nfs4 rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP> 0 0
<SERVER_IP>:/dirB /mnt/dirB nfs4 rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,acregmin=1,acregmax=1,acdirmin=1,acdirmax=1,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=<LOCALHOST_IP>,local_lock=none,addr=<SERVER_IP> 0 0

Which all seems pretty normal.

My question is: how can I measure this latency, perhaps monitor it, and deal with it? Is it inevitable? Is there a way to make it so the file won't be shown until complete? Or is there a better solution I haven't considered yet?

I installed Ubuntu Server 10.10 on VmWare. I installed apache and php and then created a virtual directory, following these steps: http://www.phpfreaks.com/tutorial/a-simple-debian-based-dev-environment

So, I now have a V-host foo.local. I wanted to see the results on my Win7 host, so I checked the IP-address with ifconfig and went there. Sadly, I'm only getting the standard "It Works" page. How can I view my vhost?

EDIT: when I say "Virtual host", I mean the PHP website. I do not mean my Guest OS Ubuntu Server. That is the Virtual Machine, on which the Virtual Host is running.

I can reach the Machine, I can't reach the specific host on it.

EDIT2: solved. I initially thought this wouldn't work. Adding the line to the hosts file did it, I was under the impression that all the hosts file does is redirect something to an IP-address. So if I'm going to 192.168.53.84 manually or telling the hosts file that foo.local points to it, I thought there would be no difference, because Win7 doesn't know what's on the Ubuntu Server. Only that it exists... oh well...

On linux distros, it's more rule than exception to install things via some sort of package. Via a manager or command line. This then configures a lot of stuff for you and it just works.

As such, there's stuff like LAMP of XAMPP.

However, I'm not content with this. I want to have the option of getting the most recent of each piece of software, and keeping it up to date.

There are a couple problems:

1. What directories do I install the individual pieces of software to?
2. How do I make them properly work together?
3. With #2 in mind: in what order do I install them?
4. Do I download the sources and compile them myself, or are there precompiled binaries I can download(not the same thing as installing LAMP)?
5. If a new version of one of the components comes out and I want to update, how do I proceed? Compile again and overwrite install folders? What about a major update, like from MySQL 4.x to 5.x?

Number 4 especially applies to PHP, since you can give a lot of command line options to compile it very specifically.

These are the questions that continue to bug me. How do I proceed?

Or at least, that's what I think is happening. There doesn't appear to be a debug command for this, or to see if something is in the routing table.

I'm testing out this setup in Packet Tracer. I have 3 routers and a webserver

From left to right, you have: Webserver -> Router1 -> Router2 -> Router3

Router1 and Router2 can succesfully ping WebServer. Router3 cannot.

Router2 has a default gateway set, to send all not-recognized data through its serial interface to Router1.

Like this: ip route 0.0.0.0 0.0.0.0 Serial 0/0/1 Serial 0/0/1 being the connection to Router1

Router2 and Router3 have OSPF configured. From their "show run":

Router2:

router ospf 1
 log-adjacency-changes
 passive-interface Serial0/0/1
 network 10.1.1.0 0.0.0.3 area 0
 default-information originate
!

Router3:

router ospf 1
 log-adjacency-changes
 network 10.1.1.0 0.0.0.3 area 0
 passive-interface FastEthernet0/0
!

I was under the assumption that setting default-information originate on Router2 would give Router3 the needed information. What's going wrong here?

The interfaces are up. Ip addresses are with mask-range, clock rate is set at correct end. I don't know what else to check.

EDIT: I was going to post a screenshot, but now it's working all of the sudden. I opened the PKT file, repositioned stuff so the labels would be clear, took the screenshot and then ran the test again, to see where the real-time analyzer said the mistake was. And it worked.

I'm sorry to have taken your time over this. I'm flabbergasted over this.

I usually look at the DNS cahce via the commandline "ipconfig/displaydns"

Someone told me the other day "you can just look it up in the Server Manager window".

I've tried and I've searched, but I can find how to view the cache here.

Is this possible, or was the person speaking of something entirly different, like an MMC snap-in?

I'm in the following situation(With SQL 2008 Express):

It says "Microsoft recommends that you use a separate account for each SQL Server service."

Okay. This is my local machine I'll be developing on, so I think I'll only need one instance.

The problem comes with the "account name" linked to the SQL Server Database Engine(the top one).

The field is clickable. Normally, both fields are blank. I picked system, but I'm not sure what effects this might have. I tried using my own username and password, but that was rejected. That last part is what worries me most.

I want to make a certain switch in the network root, but all I remember is the command "set spantree root vlan-id"

Sadly, the "set" command is not available on this switch. How do I proceed?

EDIT: I think I did it with the following command, in config mode:

spanning-tree vlan <number> root primary

Sadly, I have no idea how to confirm this. That becomes the question now.

To install Maven, I downloaded the latest version from the website and then followed these steps:

http://maven.apache.org/download.html#Installation

The last step, the version control, does not work. It says that 'mvn' is currently not installed and that I should type sudo apt-get install maven2

If I go directly to the mvn file itself, it does work:

root@ubuntu:~# /usr/local/apache-maven/apache-maven-2.2.1/bin/mvn --version
Apache Maven 2.2.1 (r801777; 2009-08-06 12:16:01-0700)
Java version: 1.6.0_21
Java home: /usr/java/jdk1.6.0_21/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "linux" version: "2.6.32-25-generic" arch: "i386" Family: "unix"

So, what am I doing wrong here? Or what would and apt-get install do extra that I might have forgotten?

I'm running WAMP on a Win7 virtual machine. I'm trying to access the server via my web browser, but it's not working.

Inside the VM, the IP address is shown to be 192.168.31.132

Going to http://192.168.31.132/ however, delivers a 403 Forbidden error.

I don't know what happened to cause this. I tried this right after installing the software, default settings all the way.

I turned off Windows Firewall on the VM, didn't change anything.

So I wonder, what setting in Apache is making this happen?

EDIT: things did work after I put the server online...

Question solved

Can someone inform me as to what is the best way to send files from my hard disk to any of my VmWare images.

I'm thinking FTP(FileZilla might be usefull), but I'm not sure how to do this.

EDIT: some people don't seem to understand: I have VmWare Server installed. I then want to be able to transfer files from the host OS, on which VmWare server is running, to whatever VMDK file I have running on VmWare server.

For instance, I now have Windows 7 RC running on VmWare, I want to send some files from my Vista, to the Windows 7 running on VmWare

Thusly, I am transfering individual files from my host onto my VMDK. I do not wish to create VMDK backups or copy the VMDK to another machine.

I'm running openSuse 11.1 on VmWare and I can't get on internet.

I'm at home, no ports blocked or anything, I've tried every single ethernet option, nothing works.

Can anybody point me at settings I might be missing?

If any of you have ever installed Ubuntu via the program Wubi, you'll have noticed an extra folder on your partition named "host".
When you open this folder, you get to see the contents of your Windows C:\> drive. You can then work with it, open files, copy files from it and to it and everything else you can do with every other folder on your partition.

When manually installing Ubuntu or any other Linux distro, this is not the case. So I'm wondering, how can I make this happen in any multi-boot environment?

Anybody who's ever worked with servers and even a small LAN environment knows (or should know) how messy things can get. Cables, routers, hubs, servers and so on.

Everything crawling where it shouldn't go, and good luck finding that one cable that's preventing John's PC to connect to the rest of the Intranet when John works on the first floor and the servers where you need to check it are on the third floor.

So, for everyone here who works in environments like this: how do you keep it clean? A clean environment means at least some improvement in efficiency, so what are you tricks? What are the absolute do's and don'ts and why?

Or do you enjoy some Spaghetti?