To install ImageMagick on CentOS, run
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yum install ImageMagick |
To install on Ubuntu/Debian, run
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apt install -y imagemagick |
Disable IP Block Alerts in CSF Firewall
To disable IP block alert in CSF firewall, run
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sed -i "s/LF_PERMBLOCK_ALERT\s*=.*$/LF_PERMBLOCK_ALERT = \"0\"/g" /etc/csf/csf.conf |
Restart lfd and csf
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systemctl restart lfd csf -r |
See csf firewall
Ignore a folder in maldet
maldet is malware scanner for linux. On a shared hosting server, maldet detected one cusomer files as malware, on checking i found it is false positive. It is just a log file written by the application. To avoid getting further email from this application, i added this folder to maldet ignore_paths.
To add a folder to ignore list, edit file
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vi /usr/local/maldetect/ignore_paths |
Add the folder you need to ignore to end of this file as a new line.
Example
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root@server74 [~]# cat /usr/local/maldetect/ignore_paths /home/welgreenkerala/public_html/login/ /usr/local/maldetect /usr/local/sbin/maldet /home/shopatke/public_html/application/logs/ root@server74 [~]# |
See maldet
Enable Passive FTP in ISPConfig
To enable Passive FTP in Debian/Ubuntu installation of ISPConfig, run
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echo "40110 40210" > /etc/pure-ftpd/conf/PassivePortRange |
Restart pure-ftpd
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service pure-ftpd-mysql restart |
Now open ports 40110-40210 in firewall.
On CSF Firewall, edit
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vi /etc/csf/csf.conf |
Add
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40110:40210 |
At ened of TCP_IN line.
Example
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TCP_IN = "20,21,22,25,53,80,110,143,443,465,587,993,995,3333,8080,8090,19999,40110:40210" |
See ispconfig
Reorder windows in tmux
To reorder windows in tmux, you can use following command
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CTRL + B + . |
Press CTRL + B or whatever prefix you use, then press . (dot). This will ask you number/position where you need current window moved.
Another method is
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CTRL + B + : |
This will give you tmux command promt. Now enter
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move-window -t 0 |
This will move current window to position 0. This only work if position 0 is empty. If another window already present in position 0, use swap-window command.
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swap-window -t 0 |
This with swap current window with window in position 0.
Another useful command is
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CTRL + B + , |
This will allow you to rename current tmux window.
Using shortcuts
You can edit .tmux.conf file and add following
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bind-key -n C-S-Left swap-window -t -1 bind-key -n C-S-Right swap-window -t +1 |
Now you can use CTRL + SHIFT + LEFT OR RIGHT arrow to move windows.
See tmux
vmstat
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[root@server70 ~]# vmstat -S M 1 10 procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 0 0 11 770 1009 3119 0 0 28 22 53 51 4 1 94 1 0 3 0 11 727 1009 3120 0 0 52 2504 8387 2624 12 1 86 1 0 0 0 11 755 1009 3120 0 0 4 157 4619 1841 12 1 86 1 0 0 0 11 755 1009 3120 0 0 136 4 9405 1595 2 1 98 0 0 0 0 11 755 1009 3120 0 0 0 33 4564 875 0 0 99 0 0 1 0 11 761 1009 3120 0 0 60 0 3151 1157 2 1 97 0 0 0 0 11 798 1009 3120 0 0 12 984 2937 898 0 0 99 0 0 0 1 11 828 1009 3120 0 0 0 321 3108 1002 3 0 96 1 0 0 0 11 813 1009 3120 0 0 4 0 6065 1512 6 1 93 0 0 1 0 11 848 1009 3120 0 0 4 100 7311 1628 3 1 95 2 0 [root@server70 ~]# |
vmstat 1
* High values in “wa” column mean: IO problem
* High values in “si”, “so” mean: excessive swapping
Sustained high swap rates (si and so) are usually bad. The system will start spending all of its time swapping, and make no progress on any actual work. You will also see the number of runnable (r and b) processes increase. If the situation gets bad enough and free memory gets too low, the Out-of-memory (oom) logic will start killing random processes. At this point, either reducing the number of processes that normally run or adding additional RAM are about the only options.
vmstat – Report virtual memory statistics
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vmstat [-a] [-n] [delay [ count]] vmstat [-f] [-s] [-m] vmstat [-S unit] vmstat [-d] vmstat [-p disk partition] vmstat [-V] |
vmstat reports information about processes, memory, paging, block IO, traps, and cpu activity.
The first report produced gives averages since the last reboot. Additional reports give information on a sampling period of length delay. The process and memory reports are instantaneous in either case.
FIELD DESCRIPTION FOR VM MODE
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Procs r: The number of processes waiting for run time. b: The number of processes in uninterruptible sleep. Memory swpd: the amount of virtual memory used. free: the amount of idle memory. buff: the amount of memory used as buffers. cache: the amount of memory used as cache. inact: the amount of inactive memory. (-a option) active: the amount of active memory. (-a option) Swap si: Amount of memory swapped in from disk (/s). so: Amount of memory swapped to disk (/s). IO bi: Blocks received from a block device (blocks/s). bo: Blocks sent to a block device (blocks/s). System in: The number of interrupts per second, including the clock. cs: The number of context switches per second. CPU These are percentages of total CPU time. us: Time spent running non-kernel code. (user time, including nice time) sy: Time spent running kernel code. (system time) id: Time spent idle. Prior to Linux 2.5.41, this includes IO-wait time. wa: Time spent waiting for IO. Prior to Linux 2.5.41, included in idle. st: Time stolen from a virtual machine. Prior to Linux 2.6.11, unknown. |
FIELD DESCRIPTION FOR DISK MODE
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Reads total: Total reads completed successfully merged: grouped reads (resulting in one I/O) sectors: Sectors read successfully ms: milliseconds spent reading Writes total: Total writes completed successfully merged: grouped writes (resulting in one I/O) sectors: Sectors written successfully ms: milliseconds spent writing IO cur: I/O in progress s: seconds spent for I/O |
FIELD DESCRIPTION FOR DISK PARTITION MODE
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reads: Total number of reads issued to this partition read sectors: Total read sectors for partition writes : Total number of writes issued to this partition requested writes: Total number of write requests made for partition |
FIELD DESCRIPTION FOR SLAB MODE
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cache: Cache name num: Number of currently active objects total: Total number of available objects size: Size of each object pages: Number of pages with at least one active object totpages: Total number of allocated pages pslab: Number of pages per slab |
Related commands
* iostat
* sar
* mpstat
* ps
* top
* free
See Linux Commands
Disable Netdata Email Notification
To disable email notifcation from netdata, run
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/etc/netdata/edit-config health_alarm_notify.conf |
Find
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SEND_EMAIL="YES" |
Replace with
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SEND_EMAIL="NO" |
By default, it open using nano, if you want to use vim to edit, select vim as default editor with
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update-alternatives --config editor |
See netdata
find files by size
On a server, i wanted to find all log files that are larger than 1 GB in size, to do this, run
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find /path/ -size +1G |
Example
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find /var/www/clients/ -name "error.log" -size +1G |
To find files older than 100 days, run
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find /var/www/clients/ -name "error.log" -mtime +100 -size +1G |
See find