change net.ipv4.tcp_keepalive

% : sysctl -p net.ipv6.conf.all.disable_ipv6 = 1 net.ipv4.tcp_syncookies = 1 net.ipv4.icmp_echo_ignore_broadcasts = 1 net.ipv4.conf.all.accept_redirects = 0 fs.aio-max-nr = 1048576 fs.file-max = 6815744 kernel.shmall = 15204352 kernel.shmmax = 62277025792 kernel.shmmni = 4096 kernel.sem = 250 32000 100 128 net.ipv4.ip_local_port_range = 9000 65500 net.core.rmem_default = 262144 net.core.rmem_max = 4194304 net.core.wmem_default = 262144 net.core.wmem_max = 1048576 vm.nr_hugepages = […]

Fix: (oracle) are not allowed to use this program (crontab)

Symptoms: [oracle@oracle01 nmon]$ crontab -l You (oracle) are not allowed to use this program (crontab) See crontab(1) for more information Cause: it turns out that Mandriva doesn’t create default rules for crontab’s use by users. Instead, on a new install crontab is restricted to the root account. There are two files that control usage of […]

Setup NMON in RHEL

Download nmon for RHEL: Install nmon in RHEL: cp nmon16e_x86_rhel72 /usr/local/bin/ chmod a+x /usr/local/bin/nmon16e_x86_rhel72 ln -s /usr/local/bin/nmon16e_x86_rhel72 /usr/local/bin/nmon Configure nmon: su – oracle mkdir /nmon cd nmon/ vi / #Syntax nmon: #[ -f | -F filename ] #[ -r < runname > ] #[ -t | -T | -Y Includes the top processes in […]

Mounting and mapping shares between Windows and Linux with Samba

Mounting and mapping shares between Windows and Linux with Samba yum install samba-client samba-common -y yum install cifs-utils # smbclient -U user -L # mkdir /mnt/myshare # mount -t cifs -o username=user // /mnt/share # sudo mount.cifs // /mnt/share/nmshare/ -o user=share,pass=share # vim /etc/fstab // /mnt/share cifs username=user,password=password,_netdev 0 0 The _netdev option is […]

Set vm of Virtual Box to access internet

[root@docker01 ~]# ping ^C [root@docker01 ~]# nslookup [root@docker01 ~]# more /etc/resolv.conf # Generated by NetworkManager search nameserver nameserver nameserver :: VirtualBox–setting–Network— Adapter1: Bridged Adapter, Promiscuous Mode:Deny, Cable Connected:enabled. Adapter2: Nat, Cable Connected:enabled. nmtui ifconfig more /etc/resolv.conf more /etc/sysconfig/network-scripts/ifcfg-enp0s3 more /etc/sysconfig/network-scripts/ cd /etc/sysconfig/network-scripts/ ls ls -lrt ifconfig ls more ifcfg-lo [root@docker01 […]

Test server connectivity via python open socket

1. Open socket via python in target vm [root@oraclevm02 ~]# python -m SimpleHTTPServer 7809 Serving HTTP on port 7809 … – – [11/Sep/2010 11:29:15] code 400, message Bad request syntax (‘\x03’) – – [11/Sep/2010 11:29:15] “” 400 – 2. Telnet target:port [root@oraclevm01 ~]telnet oraclevm01 7809

Issue: /etc/ssh/ssh_config: Bad configuration option: permitrootlogin

Issue: /etc/ssh/ssh_config: Bad configuration option: permitrootlogin Symptom: [devuser@linuxvm01 docker]$ ssh devuser@linuxvm02 /etc/ssh/ssh_config: line 26: Bad configuration option: permitrootlogin /etc/ssh/ssh_config: terminating, 1 bad configuration options Cause: To resolve this issue you have to commented out line 55 in /etc/ssh/ssh_config #PermitRootLogin yes PermitRootLogin is actually an option which is valid in the /etc/ssh/sshd_config file; not the ssh_config […]

OSWatcher via MobaXterm

1. Using MobaXterm_Portable_V10.2: oraclevm01 % sudo su – root root@oraclevm01:/root % xhost + MobaXterm X11 proxy: Unsupported authorisation protocol xhost: unable to open display “localhost:10.0” root@oraclevm01:/root % exit logout oraclevm01 % xhost + access control disabled, clients can connect from any host oraclevm01 % 2. produce report oraclevm01$ cd /opt/app/oracle/admin/OSWatch/oswbb/ oraclevm01$ ls analysis […]

Docker run OGG Classic Architecture container from CIFS with docker-volume-netshare Plugin

Docker run OGG Classic Architecture container from CIFS with docker-volume-netshare_0.36_linux_amd64 Plugin 1. Mount SMB storage to Linux as CIFS [root@linuxvm01 docker-volume-netshare_0.36_linux_amd64]# sudo mount -t cifs -o username=smb_user,file_mode=0777,dir_mode=0777,uid=54321,gid=54321 \\\\\\shared /u01 \\\shared on /u01 type cifs (rw,relatime,vers=default,cache=strict,username=smb_user,domain=,uid=54321,forceuid,gid=54321,forcegid,addr=,file_mode=0777,dir_mode=0777,soft,nounix,serverino,mapposix,rsize=1048576,wsize=1048576,echo_interval=60,actimeo=1) 2. Run docker-volume-netshare plugin with CIFS [root@linuxvm01 docker-volume-netshare_0.36_linux_amd64]# sudo ./docker-volume-netshare cifs 2019/08/16 19:13:44 Entering go-plugins-helpers getPath 2019/08/16 19:13:44 Entering go-plugins-helpers […]

mount SMB storage to Linux as CIFS

mount SMB storage to Linux as CIFS yum install cifs-utils sudo mount -t cifs -o username=smb_user,file_mode=0777,dir_mode=0777,uid=54321,gid=54321 \\\\\\shared /u01 [root@linuxvm01 ~]# more /etc/fstab # # /etc/fstab # Created by anaconda on Sun Jul 28 20:19:48 2019 # # Accessible filesystems, by reference, are maintained under ‘/dev/disk’ # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for […]