centos7 interview questions
Top centos7 frequently asked interview questions
CentOS 7 EPEL now includes Python 3.4: yum install python34
However, when I try that, even though Python 3.4 installs successfully, it doesn't appear to install pip. Which is weird, because pip should be included by default with Python 3.4. which pip3 doesn't find anything, nor does which pip.
How do I access pip from the Python 3.4 package in CentOS 7 EPEL release?
Source: (StackOverflow)
I'm using python 3.4 in a virtual environment:
(af)[root@domain backend]# pip --version
pip 7.1.0 from /home/af/af-stage/backend/.ves/af/lib/python3.4/site-packages (python 3.4)
Installation of lxml failed "error: command 'gcc' failed with exit status 4":
(af)[root@domain backend]# pip install lxml
You are using pip version 7.1.0, however version 7.1.2 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
Collecting lxml
Using cached lxml-3.5.0.tar.gz
Building wheels for collected packages: lxml
Running setup.py bdist_wheel for lxml
Complete output from command /home/af/af-stage/backend/.ves/af/bin/python3.4 -c "import setuptools;__file__='/tmp/pip-build-tlogtyk2/lxml/setup.py';exec(compile(open(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" bdist_wheel -d /tmp/tmpod9hcw0ypip-wheel-:
Building lxml version 3.5.0.
Building without Cython.
Using build configuration of libxslt 1.1.28
Building against libxml2/libxslt in the following directory: /usr/lib64
running bdist_wheel
running build
running build_py
creating build
creating build/lib.linux-x86_64-3.4
creating build/lib.linux-x86_64-3.4/lxml
copying src/lxml/usedoctest.py -> build/lib.linux-x86_64-3.4/lxml
copying src/lxml/__init__.py -> build/lib.linux-x86_64-3.4/lxml
copying src/lxml/builder.py -> build/lib.linux-x86_64-3.4/lxml
copying src/lxml/sax.py -> build/lib.linux-x86_64-3.4/lxml
copying src/lxml/doctestcompare.py -> build/lib.linux-x86_64-3.4/lxml
copying src/lxml/_elementpath.py -> build/lib.linux-x86_64-3.4/lxml
copying src/lxml/cssselect.py -> build/lib.linux-x86_64-3.4/lxml
copying src/lxml/ElementInclude.py -> build/lib.linux-x86_64-3.4/lxml
copying src/lxml/pyclasslookup.py -> build/lib.linux-x86_64-3.4/lxml
creating build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/__init__.py -> build/lib.linux-x86_64-3.4/lxml/includes
creating build/lib.linux-x86_64-3.4/lxml/html
copying src/lxml/html/usedoctest.py -> build/lib.linux-x86_64-3.4/lxml/html
copying src/lxml/html/html5parser.py -> build/lib.linux-x86_64-3.4/lxml/html
copying src/lxml/html/__init__.py -> build/lib.linux-x86_64-3.4/lxml/html
copying src/lxml/html/_html5builder.py -> build/lib.linux-x86_64-3.4/lxml/html
copying src/lxml/html/builder.py -> build/lib.linux-x86_64-3.4/lxml/html
copying src/lxml/html/_setmixin.py -> build/lib.linux-x86_64-3.4/lxml/html
copying src/lxml/html/_diffcommand.py -> build/lib.linux-x86_64-3.4/lxml/html
copying src/lxml/html/ElementSoup.py -> build/lib.linux-x86_64-3.4/lxml/html
copying src/lxml/html/formfill.py -> build/lib.linux-x86_64-3.4/lxml/html
copying src/lxml/html/soupparser.py -> build/lib.linux-x86_64-3.4/lxml/html
copying src/lxml/html/diff.py -> build/lib.linux-x86_64-3.4/lxml/html
copying src/lxml/html/defs.py -> build/lib.linux-x86_64-3.4/lxml/html
copying src/lxml/html/clean.py -> build/lib.linux-x86_64-3.4/lxml/html
creating build/lib.linux-x86_64-3.4/lxml/isoschematron
copying src/lxml/isoschematron/__init__.py -> build/lib.linux-x86_64-3.4/lxml/isoschematron
copying src/lxml/lxml.etree.h -> build/lib.linux-x86_64-3.4/lxml
copying src/lxml/lxml.etree_api.h -> build/lib.linux-x86_64-3.4/lxml
copying src/lxml/includes/etreepublic.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/uri.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/xmlschema.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/config.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/xmlerror.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/xslt.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/tree.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/xpath.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/relaxng.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/htmlparser.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/xinclude.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/xmlparser.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/schematron.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/dtdvalid.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/c14n.pxd -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/lxml-version.h -> build/lib.linux-x86_64-3.4/lxml/includes
copying src/lxml/includes/etree_defs.h -> build/lib.linux-x86_64-3.4/lxml/includes
creating build/lib.linux-x86_64-3.4/lxml/isoschematron/resources
creating build/lib.linux-x86_64-3.4/lxml/isoschematron/resources/rng
copying src/lxml/isoschematron/resources/rng/iso-schematron.rng -> build/lib.linux-x86_64-3.4/lxml/isoschematron/resources/rng
creating build/lib.linux-x86_64-3.4/lxml/isoschematron/resources/xsl
copying src/lxml/isoschematron/resources/xsl/RNG2Schtrn.xsl -> build/lib.linux-x86_64-3.4/lxml/isoschematron/resources/xsl
copying src/lxml/isoschematron/resources/xsl/XSD2Schtrn.xsl -> build/lib.linux-x86_64-3.4/lxml/isoschematron/resources/xsl
creating build/lib.linux-x86_64-3.4/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_svrl_for_xslt1.xsl -> build/lib.linux-x86_64-3.4/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_dsdl_include.xsl -> build/lib.linux-x86_64-3.4/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_abstract_expand.xsl -> build/lib.linux-x86_64-3.4/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_schematron_message.xsl -> build/lib.linux-x86_64-3.4/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/iso_schematron_skeleton_for_xslt1.xsl -> build/lib.linux-x86_64-3.4/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
copying src/lxml/isoschematron/resources/xsl/iso-schematron-xslt1/readme.txt -> build/lib.linux-x86_64-3.4/lxml/isoschematron/resources/xsl/iso-schematron-xslt1
running build_ext
building 'lxml.etree' extension
creating build/temp.linux-x86_64-3.4
creating build/temp.linux-x86_64-3.4/src
creating build/temp.linux-x86_64-3.4/src/lxml
gcc -pthread -Wno-unused-result -DDYNAMIC_ANNOTATIONS_ENABLED=1 -DNDEBUG -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -D_GNU_SOURCE -fPIC -fwrapv -fPIC -I/usr/include/libxml2 -Isrc/lxml/includes -I/usr/include/python3.4m -c src/lxml/lxml.etree.c -o build/temp.linux-x86_64-3.4/src/lxml/lxml.etree.o -w
{standard input}: Assembler messages:
{standard input}:1531298: Error: unknown pseudo-op: `.uleb'
gcc: internal compiler error: Killed (program cc1)
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://bugzilla.redhat.com/bugzilla> for instructions.
Compile failed: command 'gcc' failed with exit status 4
creating tmp
cc -I/usr/include/libxml2 -I/usr/include/libxml2 -c /tmp/xmlXPathInitpm92p5c8.c -o tmp/xmlXPathInitpm92p5c8.o
cc tmp/xmlXPathInitpm92p5c8.o -L/usr/lib64 -lxml2 -o a.out
error: command 'gcc' failed with exit status 4
----------------------------------------
Failed building wheel for lxml
Failed to build lxml
Installing collected packages: lxml
Running setup.py install for lxml
Complete output from command /home/af/af-stage/backend/.ves/af/bin/python3.4 -c "import setuptools, tokenize;__file__='/tmp/pip-build-tlogtyk2/lxml/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-99hwjy1o-record/install-record.txt --single-version-externally-managed --compile --install-headers /home/af/af-stage/backend/.ves/af/include/site/python3.4/lxml:
Building lxml version 3.5.0.
Building without Cython.
Using build configuration of libxslt 1.1.28
Building against libxml2/libxslt in the following directory: /usr/lib64
running install
running build
running build_py
copying src/lxml/includes/lxml-version.h -> build/lib.linux-x86_64-3.4/lxml/includes
running build_ext
building 'lxml.etree' extension
gcc -pthread -Wno-unused-result -DDYNAMIC_ANNOTATIONS_ENABLED=1 -DNDEBUG -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -D_GNU_SOURCE -fPIC -fwrapv -fPIC -I/usr/include/libxml2 -Isrc/lxml/includes -I/usr/include/python3.4m -c src/lxml/lxml.etree.c -o build/temp.linux-x86_64-3.4/src/lxml/lxml.etree.o -w
{standard input}: Assembler messages:
{standard input}:1320351: Error: unknown pseudo-op: `.uleb1'
gcc: internal compiler error: Killed (program cc1)
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://bugzilla.redhat.com/bugzilla> for instructions.
Compile failed: command 'gcc' failed with exit status 4
cc -I/usr/include/libxml2 -I/usr/include/libxml2 -c /tmp/xmlXPathInit3tj66iu0.c -o tmp/xmlXPathInit3tj66iu0.o
cc tmp/xmlXPathInit3tj66iu0.o -L/usr/lib64 -lxml2 -o a.out
error: command 'gcc' failed with exit status 4
----------------------------------------
Command "/home/af/af-stage/backend/.ves/af/bin/python3.4 -c "import setuptools, tokenize;__file__='/tmp/pip-build-tlogtyk2/lxml/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-99hwjy1o-record/install-record.txt --single-version-externally-managed --compile --install-headers /home/af/af-stage/backend/.ves/af/include/site/python3.4/lxml" failed with error code 1 in /tmp/pip-build-tlogtyk2/lxml
Notes:
I've already done yum install libxslt-devel libxml2-devel
Source: (StackOverflow)
I'm trying to reboot server running CentOS 7 on VirtualBox. I use this task:
- name: Restart server
command: /sbin/reboot
async: 0
poll: 0
ignore_errors: true
Server is rebooted, but I get this error:
TASK: [common | Restart server] ***********************************************
fatal: [rolcabox] => SSH Error: Shared connection to 127.0.0.1 closed.
It is sometimes useful to re-run the command using -vvvv, which prints SSH debug output to help diagnose the issue.
FATAL: all hosts have already failed -- aborting
What am I doing wrong? How can I fix this?
Source: (StackOverflow)
I am trying to resize a logical volume on CentOS7 but am running into the following error:
resize2fs 1.42.9 (28-Dec-2013)
resize2fs: Bad magic number in super-block while trying to open /dev/mapper/centos-root
Couldn't find valid filesystem superblock.
I have tried adding a new partition (using fdisk) and using vgextend to extend the volume group, then resizing.
Resize worked fine for the logical volume using lvextend, but it failed at resize2fs.
I have also tried deleting an existing partition (using fdisk) and recreating it with a larger end block, then resizing the physical volume using lvm pvresize, followed by a resize of the logical volume using lvm lvresize. Again everything worked fine up to this point.
Once I tried to use resize2fs, using both methods as above, I received the exact same error.
Hopefully some of the following will shed some light.
fdisk -l
[root@server~]# fdisk -l
Disk /dev/xvda: 32.2 GB, 32212254720 bytes, 62914560 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0009323a
Device Boot Start End Blocks Id System
/dev/xvda1 * 2048 1026047 512000 83 Linux
/dev/xvda2 1026048 41943039 20458496 8e Linux LVM
/dev/xvda3 41943040 62914559 10485760 8e Linux LVM
Disk /dev/mapper/centos-swap: 2147 MB, 2147483648 bytes, 4194304 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/mapper/centos-root: 29.5 GB, 29532094464 bytes, 57679872 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
pvdisplay
[root@server ~]# pvdisplay
--- Physical volume ---
PV Name /dev/xvda2
VG Name centos
PV Size 19.51 GiB / not usable 2.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 4994
Free PE 0
Allocated PE 4994
PV UUID 7bJOPh-OUK0-dGAs-2yqL-CAsV-TZeL-HfYzCt
--- Physical volume ---
PV Name /dev/xvda3
VG Name centos
PV Size 10.00 GiB / not usable 4.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 2559
Free PE 0
Allocated PE 2559
PV UUID p0IClg-5mrh-5WlL-eJ1v-t6Tm-flVJ-gsJOK6
vgdisplay
[root@server ~]# vgdisplay
--- Volume group ---
VG Name centos
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 6
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 2
Act PV 2
VG Size 29.50 GiB
PE Size 4.00 MiB
Total PE 7553
Alloc PE / Size 7553 / 29.50 GiB
Free PE / Size 0 / 0
VG UUID FD7k1M-koJt-2veW-sizL-Srsq-Y6zt-GcCfz6
lvdisplay
[root@server ~]# lvdisplay
--- Logical volume ---
LV Path /dev/centos/swap
LV Name swap
VG Name centos
LV UUID KyokrR-NGsp-6jVA-P92S-QE3X-hvdp-WAeACd
LV Write Access read/write
LV Creation host, time localhost, 2014-10-09 08:28:42 +0100
LV Status available
# open 2
LV Size 2.00 GiB
Current LE 512
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0
--- Logical volume ---
LV Path /dev/centos/root
LV Name root
VG Name centos
LV UUID ugCOcT-sTDK-M8EV-3InM-hjIg-2nwS-KeAOnq
LV Write Access read/write
LV Creation host, time localhost, 2014-10-09 08:28:42 +0100
LV Status available
# open 1
LV Size 27.50 GiB
Current LE 7041
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:1
I've probably done something stupid, so any help would be greatly appreciated!
Source: (StackOverflow)
Due to a misconfiguration I've migrated a VPS from CentOs 6 to CentOs 7 for a fresh start. Among other things I had a beanstalkd service installed on CentOs 6.
At the time I've followed this tutorial http://viewsfromtheside.com/2014/06/12/install-beanstalkd-centos-6/ and it worked perfectly for me.
But now, I can't install Beanstalkd on my CentOs 7 version.
I used those line for EPEL repo :
# wget http://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-2.noarch.rpm
# rpm -ivh epel-release-7-2.noarch.rpm
Then I tried :
# yum install beanstalkd --enablerepo=epel-testing
and :
# yum --disablerepo="*" --enablerepo="epel" list available | grep 'beanstalkd'
and even :
# yum search beanstalkd
But still : No matches found for: beanstalkd ...
I am new to CentOs and EPEL repos, so maybe I missed something ? Anyway, how can I install Beanstalkd on CentOs 7 ?
Source: (StackOverflow)
I installed Centos7 minimal and then: ansible, docker, pip and using pip I installed docker-py.
Versions:
- Docker version 1.6.0, build 8aae715/1.6.0
- ansible 1.9.1
- docker_py-1.2.2
Trying to run a playbook, for example
- name: redis container
docker:
name: myredis
image: redis
state: started
i get msg: docker-py doesn't seem to be installed, but is required for the Ansible Docker module.
I can't see the problem. Is it the CentOS, docker and ansible version?
PS: I disabled the firewalld and SELinux
Any ideas?
Thanks
Source: (StackOverflow)
Recently I had the problem of starting a postgresql service with custom PGDATA path. It tried to look in the default data directory (/var/lib/pgsql/9.3/data/) which was not initialized and therefore triggered these errors. It appears the problem is that the service starter on Centos 7 strips all the environment variables, including PGDATA.
Interesting thread on the issue
Is there a way to configure
service postgresql-9.3 start
to use custom environment variables? Are there configuration files for services where these variables have to be defined?
Thank you in advance!
Source: (StackOverflow)
I have a file that is very large (>500GB) that I want to prepend with a relatively small header (<20KB). Doing commands such as:
cat header bigfile > tmp
mv tmp bigfile
or similar commands (e.g., with sed) are very slow.
What is the fastest method of writing a header to the beginning of an existing large file? I am looking for a solution that can run under CentOS 7.2. It is okay to install packages from CentOS install or updates repo, EPEL, or RPMForge.
It would be great if some method exists that doesn't involve relocating or copying the large amount of data in the bigfile. That is, I'm hoping for a solution that can operate in fixed time for a given header file regardless of the size of the bigfile. If that is too much to ask for, then I'm just asking for the fastest method.
Source: (StackOverflow)
Brand new instance using Vagrant file
VAGRANTFILE_API_VERSION = "2"
Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
config.vm.box = "chef/centos-7.0"
config.vm.network "forwarded_port", guest: 3000, host: 3007
end
Then ran the following commands
vagrant up
vagrant ssh
sudo su
yum install -y docker
systemctl status docker.service
which all ran fine.
Then the errors:
[root@localhost vagrant]# sudo systemctl start docker
Job for docker.service failed. See 'systemctl status docker.service' and 'journalctl -xn' for details.
[root@localhost vagrant]# systemctl status docker.service -l
docker.service - Docker Application Container Engine
Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled)
Active: failed (Result: exit-code) since Fri 2015-04-03 18:56:57 UTC; 26min ago
Docs: http://docs.docker.com
Process: 10359 ExecStart=/usr/bin/docker -d $OPTIONS $DOCKER_STORAGE_OPTIONS $DOCKER_NETWORK_OPTIONS $ADD_REGISTRY $BLOCK_REGISTRY $INSECURE_REGISTRY (code=exited, status=127)
Main PID: 10359 (code=exited, status=127)
Apr 03 18:56:57 localhost.localdomain systemd[1]: Starting Docker Application Container Engine...
Apr 03 18:56:57 localhost.localdomain docker[10359]: time="2015-04-03T18:56:57Z" level="info" msg="+job serveapi(unix:///var/run/docker.sock)"
Apr 03 18:56:57 localhost.localdomain docker[10359]: /usr/bin/docker: relocation error: /usr/bin/docker: symbol dm_task_get_info_with_deferred_remove, version Base not defined in file libdevmapper.so.1.02 with link time reference
Apr 03 18:56:57 localhost.localdomain systemd[1]: docker.service: main process exited, code=exited, status=127/n/a
Apr 03 18:56:57 localhost.localdomain systemd[1]: Failed to start Docker Application Container Engine.
Apr 03 18:56:57 localhost.localdomain systemd[1]: Unit docker.service entered failed state.
[root@localhost vagrant]# journalctl -xn
-- Logs begin at Fri 2015-04-03 18:41:26 UTC, end at Fri 2015-04-03 19:01:01 UTC. --
Apr 03 19:01:01 localhost.localdomain CROND[10368]: (root) CMD (run-parts /etc/cron.hourly)
Apr 03 19:01:01 localhost.localdomain run-parts(/etc/cron.hourly)[10371]: starting 0anacron
Apr 03 19:01:01 localhost.localdomain anacron[10377]: Anacron started on 2015-04-03
Apr 03 19:01:01 localhost.localdomain anacron[10377]: Will run job `cron.daily' in 35 min.
Apr 03 19:01:01 localhost.localdomain anacron[10377]: Will run job `cron.weekly' in 55 min.
Apr 03 19:01:01 localhost.localdomain anacron[10377]: Will run job `cron.monthly' in 75 min.
Apr 03 19:01:01 localhost.localdomain anacron[10377]: Jobs will be executed sequentially
Apr 03 19:01:01 localhost.localdomain run-parts(/etc/cron.hourly)[10379]: finished 0anacron
Apr 03 19:01:01 localhost.localdomain run-parts(/etc/cron.hourly)[10381]: starting 0yum-hourly.cron
Apr 03 19:01:01 localhost.localdomain run-parts(/etc/cron.hourly)[10385]: finished 0yum-hourly.cron
Ideas as to how to get this working?
Source: (StackOverflow)
I'm looking for a way to get a working Common Lisp compiler in CentOS 7.
It seems that neither base or EPEL repos contain any of the widely available open-source Lisp compilers. There are bits of info regarding CLISP and SBCL on CentOS 6 but none about any compiler on CentOS 7.
Am I missing something here or has the switch from RHEL6 to RHEL7 completely forgot about CL compilers ?
Source: (StackOverflow)
I am using CentOS 7 and seting up a new server.
Whilst logged in as root, I have installed multiple perl modules through CPAN. Unfortunately, they seem to have installed inside root's home directory. I didn't notice this until all the modules were installed, but most of them have locations like this now:
/root/perl5/lib/perl5/5.16.3/x86_64-linux-thread-multi
/root/perl5/lib/perl5/5.16.3
/root/perl5/lib/perl5/x86_64-linux-thread-multi
/root/perl5/lib/perl5 /usr/local/lib64/perl5
This means that, for users other than root, these modules essentially do not exist, as the permissions lock them out of that directory.
I know I could solve this by giving all users read access to /root, but I'd rather not.
So, I have a few specific questions to ask:
- What did I do wrong? Did I skip an option in CPAN the first time it
ran? (CPAN config is pasted below)
- What is the best way to clean this up? I presume I need to uninstall the modules, change my config, and then reinstall them? Experienced advice is appreciated.
- What is the ideal general installation directory for CentOS 7? Where do I want to move them to? I assumed CPAN would put them in an ideal default
location.
All advice gratefully received.
cat MyConfig.pm
$CPAN::Config = {
'applypatch' => q[],
'auto_commit' => q[1],
'build_cache' => q[100],
'build_dir' => q[/root/.cpan/build],
'build_dir_reuse' => q[0],
'build_requires_install_policy' => q[yes],
'bzip2' => q[],
'cache_metadata' => q[1],
'check_sigs' => q[0],
'colorize_output' => q[0],
'commandnumber_in_prompt' => q[1],
'connect_to_internet_ok' => q[1],
'cpan_home' => q[/root/.cpan],
'ftp_passive' => q[1],
'ftp_proxy' => q[],
'getcwd' => q[cwd],
'gpg' => q[/bin/gpg],
'gzip' => q[/bin/gzip],
'halt_on_failure' => q[0],
'histfile' => q[/root/.cpan/histfile],
'histsize' => q[100],
'http_proxy' => q[],
'inactivity_timeout' => q[0],
'index_expire' => q[1],
'inhibit_startup_message' => q[0],
'keep_source_where' => q[/root/.cpan/sources],
'load_module_verbosity' => q[none],
'make' => q[/bin/make],
'make_arg' => q[],
'make_install_arg' => q[],
'make_install_make_command' => q[/bin/make],
'makepl_arg' => q[],
'mbuild_arg' => q[],
'mbuild_install_arg' => q[],
'mbuild_install_build_command' => q[./Build],
'mbuildpl_arg' => q[],
'no_proxy' => q[],
'pager' => q[/bin/less],
'patch' => q[/bin/patch],
'perl5lib_verbosity' => q[none],
'prefer_external_tar' => q[1],
'prefer_installer' => q[MB],
'prefs_dir' => q[/root/.cpan/prefs],
'prerequisites_policy' => q[follow],
'scan_cache' => q[atstart],
'shell' => q[/bin/bash],
'show_unparsable_versions' => q[0],
'show_upload_date' => q[0],
'show_zero_versions' => q[0],
'tar' => q[/bin/tar],
'tar_verbosity' => q[none],
'term_is_latin' => q[1],
'term_ornaments' => q[1],
'test_report' => q[0],
'trust_test_report_history' => q[0],
'unzip' => q[],
'urllist' => [q[http://mirror.sov.uk.goscomb.net/CPAN/], q[http://ww
+w.mirrorservice.org/sites/cpan.perl.org/CPAN/], q[http://cpan.mirrors
+.ovh.net/ftp.cpan.org/]],
'use_sqlite' => q[0],
'version_timeout' => q[15],
'wget' => q[/bin/wget],
'yaml_load_code' => q[0],
'yaml_module' => q[YAML],
};
1;
__END__
Source: (StackOverflow)
I just installed a fresh instance of a Centos 7
Linux version 3.10.0-229.1.2.el7.x86_64 (builder@kbuilder.dev.centos.org) (gcc version 4.8.2 20140120 (Red Hat 4.8.2-16) (GCC) ) #1 SMP Fri Mar 27 03:04:26 UTC 2015
I installed a mongodb 3.0 and when I connect I have this weird message:
2015-04-15T07:48:55.583+0000 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
2015-04-15T07:48:55.583+0000 I CONTROL [initandlisten] ** We suggest setting it to 'never'
2015-04-15T07:48:55.583+0000 I CONTROL [initandlisten]
2015-04-15T07:48:55.583+0000 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
2015-04-15T07:48:55.583+0000 I CONTROL [initandlisten] ** We suggest setting it to 'never'
How do I disable THP for this version?
Things I tried without luck
I can disable it running this command:
echo never > /sys/kernel/mm/transparent_hugepage/enabled
echo never > /sys/kernel/mm/transparent_hugepage/defrag
But when I reboot the problem appears again.
I tried to modify /etc/rc.local adding those lines:
if test -f /sys/kernel/mm/transparent_hugepage/defrag; then
echo never > /sys/kernel/mm/transparent_hugepage/defrag
fi
if test -f /sys/kernel/mm/transparent_hugepage/enabled; then
echo never > /sys/kernel/mm/transparent_hugepage/enabled
fi
exit 0
made a reboot and no results
I also tried to modify /etc/default/grub ...
Source: (StackOverflow)
This question already has an answer here:
A CentOS 7 devbox has Java 8 installed. I need to use Java 7 to compile jars. So I downloaded and installed Java 7, but java -version still shows Java 8. How can I make sure that Java 7 is used to compile a jar at the command line?
Here are the steps I took to install Java 7:
# wget --no-check-certificate --no-cookies --header "Cookie: oraclelicense=accept-securebackup-cookie" http://download.oracle.com/otn-pub/java/jdk/7u75-b13/jdk-7u75-linux-x64.rpm
# rpm -ivh jdk-7u75-linux-x64.rpm
# export JAVA_HOME=/usr/java/latest
# java -version
java version "1.8.0_45"
Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)
As you can see, java -version still points to Java 8, even though /usr/java/latest points to the Java 7 version that was just downloaded and installed.
The command I want to run is java -jar gs-actuator-service-0.1.0.jar. Can someone show how to change the syntax in that specific command to specify the Java 7 version? Or do I need to remove Java 8? If so, what specific steps do I take?
Source: (StackOverflow)
Through some longevity testing with docker (docker 1.5 and 1.6 with no memory limit) on (centos 7 / rhel 7) and observing the systemd-cgtop stats for the running containers, I noticed what appeared to be very high memory use. Typically the particular application running in a non-containerized state only utilizes around 200-300Meg of memory. Over a 3 day period I ended up seeing systemd-cgtop reporting that my container was up to 13G of memory used. While I am not an expert Linux admin by any means, I started digging in to this which pointed me to the following articles:
http://unix.stackexchange.com/questions/34795/correctly-determining-memory-usage-in-linux
http://corlewsolutions.com/articles/article-6-understanding-the-free-command-in-ubuntu-and-linux
So basically what I am understanding is to determine the actual free memory within the system unit would be to look at the -/+ buffers/cache: within "free -m" and not the top line, as I also noticed that the top line within "free -m" would constantly increase with memory used and constantly show a decreased amount of free memory just like what I am observing with my container through systemd-cgtop. If I observe the -/+ buffers/cache: line I will see the actual stable amounts of memory being used / free. Also, if I observe the actual process within top on the host, I can see the process itself is only ever using less then 1% of memory (0.8% of 32G).
I am a bit confused as to whats going on here. If I set a memory limit of 500-1000M for a container (I believe it would turn out to be twice as much due to the swap) would my process eventually stop when I reach my memory limit, even though the process itself is not using anywhere near that much memory? If anybody out there has any feedback on the former, that would be great. Thanks!
Source: (StackOverflow)