Got two drives on this server, which one is ssd again ?
# cat /sys/block/sda/queue/rotational 1 # cat /sys/block/sdb/queue/rotational 0
sdb 🙂
textbook example of why open source software is best
So my server was sending me emails such as
Failed to check for updates with the following error message: Failed to build transaction: Success - empty transaction
I knew this was from yum-cron which I’d recently setup.
1 google search sent me to bugzilla where a guy already have pinpointed the error in a python script and is kind enough to show a diff on the code.
He also links to his pull request on the actual code repo over at github.
This patch haven’t made it through to my updates repo for my server yet, but since all this is transparent readable code I can patch my own script.
Varnish won’t start with unused backends defined
Unused backend somebackend, defined:
Is solved with
-p vcc_err_unref=off
In CentOS / RHEL you can add that to
/etc/sysconfig/varnish
You’d also have to pass that option if you’re testing your vcl config
varnishd -p vcc_err_unref=off -C -f /etc/varnish/default.vcl
Inspect values in memcached with memcdump
You can dump stuff from memcached with memcdump
$ memcdump --servers=127.0.0.1
Drown security vulnerability
Protect yourself from drown attack by updating your openssl package.
Redhat patched openssl 1.0.1e
# rpm -q --changelog openssl-1.0.1e-51.el7_2.4.x86_64 | head * Wed Feb 24 2016 Tomáš Mráz <tmraz@redhat.com> 1.0.1e-51.4 - fix CVE-2016-0702 - side channel attack on modular exponentiation - fix CVE-2016-0705 - double-free in DSA private key parsing - fix CVE-2016-0797 - heap corruption in BN_hex2bn and BN_dec2bn * Tue Feb 16 2016 Tomáš Mráz <tmraz@redhat.com> 1.0.1e-51.3 - fix CVE-2015-3197 - SSLv2 ciphersuite enforcement - disable SSLv2 in the generic TLS method
goto https://drownattack.com/ for more info
Reset owncloud admin password
I lost password for my owncloud admin account .
In owncloud 7 / 8 you have an occ command you can use to fix that ( requires root access to the server ) .
sudo -u apache php /path/to/webroot/owncloud/occ user:resetpassword [you admin username]
Thank you 2daygeek.com
Cluster ssh with nice fonts !
Cluster ssh is super nice, but out of the box it got ugly and small fonts.
Here’s my Cluster ssh config, which I respectfully ripped from the net:
# $HOME/.clusterssh/config terminal_args=-fa 'DejaVu Sans Mono:style=Book' -fs 11 # note these are not consistent with the TTF font selection, so have to 'adjust' accordingly #terminal_size=80x24 # for terminal_args=-fa 'DejaVu Sans Mono:style=Book' -fs 12: #terminal_size=133x36 # for terminal_args=-fa 'DejaVu Sans Mono:style=Book' -fs 11 terminal_size=120x34
Thank you dansnotebook.blogspot.no
Joining ~18000 lines, thnx vim
after some grep, sed and awk’ing I had sorted out a bunch of foldernames into a file, feelin’ smug about it.
I needed those on one line, using vim the only hinder was my not-so-super-skills in vim .
In vim command mode, typing ‘18000J’ would join current line with the next 18000 lines
thnx stackoverflow.com
Git, who’s the author of that branch ?
While branches keep piling up in a project and I lost track of which branches _I_ created and forgot to cleanup/delete later, this oneliner helped me out:
$ git for-each-ref --format='%(committerdate) %09 %(authorname) %09 %(refname)' | sort -k5n -k2M -k3n -k4n
thnx stackoverflow.com
CentOS 7 firewall-cmd
Current zone
# firewall-cmd --get-active-zones public interfaces: eth0
What’s active in this zone ?
# firewall-cmd --zone=public --list-all public (default, active) interfaces: eth0 sources: services: dhcpv6-client http https ssh ports: masquerade: no forward-ports: icmp-blocks: rich rules: