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1500 questions
52
votes
4 answers

Should I edit /etc/crontab or run crontab -e as root?

I'm setting up regular system maintenance tasks which have to run as root. I plan to use the flavour of cron which comes with Ubuntu 14.04 LTS as the default. I see the previous admin (who since left the company) edited /etc/crontab directly.…
marcv81
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52
votes
8 answers

Can I create SSH to tunnel HTTP through server like it was proxy?

Say I have a server and client. I need to create connection from client to a website through server like it was proxy. Is it possible to do this using a SSH tunel, or do I have to install some proxy service to the server?
Jakub Arnold
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52
votes
4 answers

Start N processes with one systemd service file

I found this systemd service file to start autossh to keep up a ssh tunnel: https://gist.github.com/thomasfr/9707568 [Unit] Description=Keeps a tunnel to 'remote.example.com' open After=network.target [Service] User=autossh # -p [PORT] # -l…
guettli
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52
votes
6 answers

How useful is mounting /tmp noexec?

Many people (including the Securing Debian Manual) recommend mounting /tmp with the noexec,nodev,nosuid set of options. This is generally presented as one element of a 'defense-in-depth' strategy, by preventing the escalation of an attack that lets…
Phil Miller
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52
votes
6 answers

e1000e Reset adapter unexpectedly / Detected Hardware Unit Hang

I have a Dell 1U Server with Intel(R) Xeon(R) CPU L5420 @ 2.50GHz, 8 cores running Ubuntu Server Kernel Version 3.13.0-32-generic on x86_64. It has dual 1000baseT networking cards. I have it set up to forward packets from eth0 to eth1. I have…
Kyle Coots
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52
votes
10 answers

Windows TCP Window Scaling Hitting plateau too early

Scenario: We have a number of Windows clients regularly uploading large files (FTP/SVN/HTTP PUT/SCP) to Linux servers that are ~100-160ms away. We have 1Gbit/s synchronous bandwidth at the office and the servers are either AWS instances or…
SmallClanger
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52
votes
1 answer

What's the difference between import virtual machines types in Hyper-V?

I was importing a virtual machine to my Hyper-V manager and I got 3 options: Register the virtual machine in place (use the existing unique ID) Restore the virtual machine in place (use the existing unique ID) Copy the virtual machine (create a new…
user214512
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52
votes
3 answers

Configure multiple SSL certificates in Haproxy

My haproxy instance serves 2 domains (mostly to avoid XSS on the main site). The rules look something like this bind :443 ssl crt /etc/ssl/haproxy.pem acl is_static hdr_end(Host) -i example.com acl is_api hdr_end(Host) -i api.example.com acl…
user22711
52
votes
1 answer

Fibre channel long distance woes

I need a fresh pair of eyes. We're using a 15km fibre optic line across which fibrechannel and 10GbE is multiplexed (passive optical CWDM). For FC we have long distance lasers suitable up to 40km (Skylane SFCxx0404F0D). The multiplexer is limited by…
Marki
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52
votes
5 answers

PDU wiring - is this normal (or even safe)?

I removed the side panel of our server rack so I can clean up some of the wiring. Inside I found the PDU was wired like in the picture. Instead of an incoming power cable, there's just 3 uninsulated spade connectors. Is there any reason for wiring…
Grant
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52
votes
3 answers

Do I need to restart my server after editing fstab and mtab?

I'm just wondering if I need to restart my server after editing fstab and mtab. I changed something in this file manually due to problem with awstats report. I am using ISPConfig 3 with the help of the tutorial from howtoforge. But due to…
jaypabs
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52
votes
6 answers

How to automatically close netcat connection after data is sent?

I am executing the following command from a script: echo '{"hostUp": true}' | sudo /usr/local/bin/netcat localhost 8001 However, the netcat client stays open indefinitely. How can I close the connection once this data has been sent?
Justin Meltzer
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52
votes
3 answers

ipmitool - can't find /dev/ipmi0 or /dev/ipmidev/0

Based on a previous question, I installed ipmitool (yum install ipmitool). Even after a reboot, though, i get the following error when trying to run ipmitool power status: Could not open device at /dev/ipmi0 or /dev/ipmi/0 or /dev/ipmidev/0: No such…
warren
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52
votes
4 answers

Can a CNAME DNS record point to a subdirectory

Can a DNS record point to an address like my.domain.com/subdir1
Hannes de Jager
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52
votes
1 answer

nginx server directive is not allowed here

I know there are dupes of this out there, but I can't seem to solve this in my situation. I'm following an article on setting up nginx as reverse proxy with apache. And I get this error: nginx: [emerg] "server" directive is not allowed here in …
gideon
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