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1500 questions
66
votes
5 answers
Correct way to move kvm vm
I'm wondering what is the correct way of moving a VM between two KVM hosts without using any kind of shared storage
Would copying the disk files and the XML dump from the source KVM machine to the destination one suffice? If so, what commands need…
Onitlikesonic
- 1,291
- 5
- 19
- 25
66
votes
7 answers
DNS failing to propagate worldwide
I haven't changed anything related to the DNS entry for serverfault.com, but some users were reporting today that the serverfault.com DNS fails to resolve for them.
I ran a justping query and I can sort of confirm this -- serverfault.com dns appears…
Jeff Atwood
- 13,264
66
votes
1 answer
Why are my XFS filesystems suddenly consuming more space and full of sparse files?
I've run XFS filesystems as data/growth partitions for nearly 10 years across various Linux servers.
I've noticed a strange phenomenon with recent CentOS/RHEL servers running version 6.2+.
Stable filesystem usage became highly variable following…
ewwhite
- 201,205
66
votes
7 answers
How to convert 'dmesg' time format to 'real' time format
I have (for example) this log entry in dmesg output:
[600711.395348] do_trap: 6 callbacks suppressed
Is there a possibility to convert this 'dmesg' time to 'real' time to know, when this event happend?
Jan Marek
- 2,230
66
votes
19 answers
The perfect server room?
What do I have to consider when I'm planning a new server room for a small company (30 PCs, 5 servers, a couple of switches, routers, UPS...)?
What are the most important aspects in order to protect the hardware?
What things do not belong in a…
splattne
- 28,776
66
votes
7 answers
What are the drawbacks of running a database inside a virtual machine? How do I overcome them?
Running anything inside a virtual machine will have some level of performance hit, but how much does it really impact the performance of a database system?
I found this academic reference paper with some interesting benchmarks, but it was a limited…
Russ
- 713
66
votes
14 answers
Why would you use IPv6 internally?
Of course, I realize the need to go to IPv6 out on the open Internet since we are running out of addresses, but I really don't understand why there is any need to use it on an internal network. I have done zero with IPv6, so I also wonder: Won't…
KCotreau
- 3,461
66
votes
3 answers
What's the difference between socat and netcat?
I understand that socat is described as a "more advanced" version of netcat, but what is the actual difference?
Would it be correct to say that everything you can do in netcat you can also do in socat? What about the opposite (everything you can do…
bantic
- 1,639
- 3
- 15
- 17
66
votes
4 answers
How to use nginx to proxy to a host requiring authentication?
How can I setup an nginx proxy_pass directive that will also include HTTP Basic authentication information sent to the proxy host?
This is an example of the URL I need to proxy to:
http://username:password@192.168.0.5/export?uuid=1234567890
The…
bwizzy
- 1,345
66
votes
4 answers
How to: 1 Cron Job every ODD minutes and 1 other every EVEN minutes?
I have 2 cron jobs, i want one of them to run every odd minute (1,3,5,7,9,11....57,59)
and i want the other one to run every even minute (0,2,4,6,8,10,12...58)
how can i do it in an easy way? (no scripting - just cron job rules)
wabbajay
- 669
66
votes
5 answers
A better Unix 'find' with parallel processing
The Unix find(1) utility is very useful, allowing me to perform an action on many files that match certain specifications, e.g.,
find /dump -type f -name '*.xml' -exec java -jar ProcessFile.jar {} \;
The above might run a script or tool over every…
PP.
- 3,606
66
votes
7 answers
What permissions are needed to write a PID file in /var/run?
On Ubuntu:
touch: cannot touch `/var/run/test.pid': Permission denied
I am starting start-stop-daemon and like to write the PID file in /var/run
start-stop-daemon is run as my-program-user
/var/run setting is drwxr-xr-x 9 root root
I like to…
s5804
- 785
66
votes
7 answers
Apache 2 startup warning: NameVirtualHost *:80 has no VirtualHosts
When my Ubuntu Apache server (Apache 2) starts up I get a warning message that reads:
[warn] NameVirtualHost *:80 has no VirtualHosts
However, the web server is working fine. What might I have wrong in my site's configuration to make it give me…
Kit Roed
- 763
66
votes
19 answers
How do you document a network?
I'm not sure how to ask this question, since I'm not in the field. Say you're a network admin and you leave your job. How does the new guy know where to start?
Esteban Araya
- 921
66
votes
12 answers
Subversion error: (405 Method Not Allowed) in response to MKCOL
I am getting the following error while trying to commit a new directory addition.
svn: Commit failed (details follow):
svn: Server sent unexpected return value (405 Method Not Allowed) in response to MKCOL request for '....
I have never seen this…
Sergio del Amo
- 835