pufferfish's questions

I'm looking for a way to periodically check a file system tree for permissions that have been set incorrectly.

The context is:

• this is in an academic compute environment, with students, researchers and overworked sysadmins
• the focus is not on malicious actors, but rather mistakes made by any of the above
• existing users/group hierarchy
• prevention does not have to be immediate, we're thinking of something that can run daily
• ideally don't want to have to install extra tools such as tripwire
• don't need a forensic trail to be captured

My hunch is a script that:

• runs daily via cron
• runs as a user with read permissions for the entire tree
• checks that rwx is off for the "all" bits.. (more rules to be added)

Before I start this, is there an established way to do this that I'm not aware of?

I'm running a Hyper-V cluster with three nodes that host a collection of VMs between them. When we need to service a node we can live migrate the roles on that node to one of the others.

What is the correct way to implement the constraint that two specific VMs should be running on the same node, whichever node that is?

When outside our company firewall, I use a script to tunnel via SSH and expose our internal wiki to my OSX machine. Is there a command to temporarily tell OSX to resolve to my local port when the tunnel is set up?

The sequence I'm hoping to use is:

1. open the tunnel ssh -f external-proxy.example -L 8001:internal-wiki.example:8000 -N

2. [DO SOMETHING HERE]

3. typing the URL internal-wiki.example:8000 in my browser causes it to transparently view localhost:8001

Other details:

• I could edit /etc/hosts but that would be a persistent change. I want to use this only when outside
• We're not using SSL or certs.

Is there a way to measure/report the overall latency in a tunneled SSH session?

My particular setup is:

• Client (OS X + wifi router + ADSL modem)
• Gateway SSH server exposed to Internet
• Internal SSH target to which I'm tunneling

I'm interested in seeing the latency between the console on my local machine and the final machine on which I have the session open.

I have a software RAID5 array with 4 + 1 disks in which 2 of the disks have failed. I'm hoping that with some percussive maintenance, I might get one of the failed disks working again long enough to do a block level copy to get the image off.

The plan would be to make images of 4 (or all 5) of the disks with dd, and then try rebuild the array on those images.

Is there something right off the bat that I've missed that would make this impossible? If not, how would I:

1. Copy an image of each device to a file
2. Mount these
3. Reconfigure mdadm to use these images as the devices

Obviously, there are a lot of things that might have happened that make the data corrupt, but there are reasons to think the actual data might be intact across the 4 disks:

1. The second disk failure might have been due to power loss
2. The data I'm interested in recovering wasn't written after the first failure

What is the easiest way to "patch" an Ubuntu ISO so that the default mirror is different?

Details:

• We're behind a proxy so upon initial installations, the process isn't able to the see the mirror
• We do have an internal mirror I'd like to point to
• I'm looking for something easy so that future ISOs can just be "patched" then burned

I'm looking for a quick way to compare directory contents. Is it possible to do an md5sum (or equivalent checksum) of an entire directory?

Using Ubuntu Linux

How do I upgrade an older version of Ubuntu Server (Jaunty, for example) to a specific later version (Lucid, for example) using the command line?

I'm concerned that dist-upgrade is going to update to the latest, which is not LTS

clarification:

• has to be command line
• our internal mirror has removed the Jaunty images
• tried editing /etc/update-manager/release-upgrades to use only LTS versions, but it hangs. (trying to reach an outside server?)

Update: It seems Jaunty to Lucid is not possible (directly) ref, but my question was still for the more general case

How do I find what Rocks version I'm running?

I've tried:

• Looking on the Ganglia page
• uname -a
• Google

so far, no luck

Is there a way that my users can kill their own jobs that are stuck in the dr state?

qstat -f <jobid>

as the user, returns

job <jobid> is already in deletion

yet when run as root it does get deleted

Is there a command to test whether jumbo frames are actually working? i.e. some sort of "ping" that reports whether or not the packet was broken up along the way.

I've an ESXi host with an Ubuntu VM which mounts a Dell MD3000i via iSCSI. I suspect jumbo frames are not enabled on the switch, and can't easily get admin access to it. I have the option to connect the disk array directly to the ESXi host, but would like some way of confirming that jumbo frames are a problem first.

Is there a feature (or plugin, or macro) in Trac that allows one to include sections from other wiki pages?

For instance, if each of my servers has a wiki page about it, and a section on the DNS info, is it possible to create a page that contains only the DNS sections of all the server pages? A link to the live section of course, not a copy.

Even better, some way to label sections and then have automatic summaries of them. e.g. Label a section "troubleshooting" on a server's page and it gets included in the "troubleshooting" summary page.

What is the simplest way to check read/write performance to a specific location (e.g. a mounted iSCSI device).

I suspect I can't use hdparm because that's lower level. Am I right?

I would like to make a VNC connection from home to a Windows machine at work. The Windows machine is not accessible from the outside, but there is a Linux box that does have port 22 open, so it would seem that this can be done.

I suspect it's just a command that "forwards" connections to port 22 on the Linux machine to the Windows machine? Just can't find an example that does exactly this though

Thanks in advance!

Is there a simple ping-like command to test whether a DHCP service is running on a network? ...on Linux

I'm looking for a way to monitor a process, and relaunch the executable if the process dies for whatever reason. Does Linux have a built-in tool that can do this?

How do I uninstall Python packages that have been built from source and installed via...

python setup.py build
python setup.py install

?

Which ports (and/or protocols) should be given priority for WinSCP to connect to a *nix machine?

Details:

I have a Windows client running WinSCP, which connects through a WRT54 router (running Tomato) to a remote Ubuntu server. The Tomato router has Quality of Service options which allow me to specify what ports and protocols get priority.

What settings do I need to add to classify WinSCP?

I'm looking for a solution in Ubuntu that indexes PDF (and ps?) files for searching later.

The criteria would be:

1. Compatibility: Often extracting text varies, depending on what software was used to create the PDF. Some PDFs can also be "locked", which I guess one should respect.
2. Search functionality: wildcards, regex's, "fuzzy" matching.
3. Speed of search

In my case I want to index a folder of academic journal articles, hence the requirement that it works consistently regardless of what software created the PDF. I'm already using a reference manager so would rather not replace that.

For example: A good front-end to Beagle, and a plugin that allows it to index PDFs would be perfect.

Is there a way to view the actual commands that have been scheduled to execute using the GNU at command? atq just gives the job ids and execution time, I need to see the command.

p.s. In my case the distro is Ubuntu