Grid

How to Build SSH Equivalency Between Two Servers

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In this post, we will introduce two kinds of ways to build user’s SSH equivalency. Build SSH Equivalency Manually Build SSH Equivalency by Oracle Scripts Build SSH Equivalency Manually Before 11g, Oracle Universal Installer (OUI) does not setup the passwordless SSH connectivity during the installation time, we have to build the SSH equivalency between nodes […]
Linux

How To Bind Multiple IP Addresses to One Network Interface on Enterprise Linux 7

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Here are the steps that you can add more IP address into the network card.Copy the configuration file of eth0 as eth0:0[root@test ~]# cp -p /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth0:0Modify the configuration[root@test ~]# vi /etc/sysconfig/network-scripts/ifcfg-eth0:0…DEVICE=eth0:0…IPADDR=192.168.0.111…Take the network effective.[root@test ~]# systemctl restart networkVerify the result[root@test ~]# ip a s eth02: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen […]
Linux

How to Sync Time Server Manaully

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After starting the server, I found that the date time a little bit deviated from the time server.[root@primary01 ~]# ntpq -p     remote           refid      st t when poll reach   delay   offset  jitter============================================================================== venus.stu.edu.t 133.100.8.2      2 u    1   64    1  108.968  1894.81   […]
BIND

How to Make Forwarders of BIND Named Server Work

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Your DNS might not cache all the records of internet, but you can forward the query to external DNS for servicing your clients.There’re two entries that you must know:The option forwarders must be added to indicate which external DNS to forward the queries.The option dnssec-validation must be set to no. dnssec-validation indicates that a resolver […]
EXT4

How to Reduce Logical Volume Size on Linux

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Since I found there’s no free space in the main volume group for extending other volumes, so I intend to shrink some non-critical volumes to squeeze some more free space.[root@test ~]# vgs  VG           #PV #LV #SN Attr   VSize  VFree  vg_test        1   3   0 wz–n- […]
EXT4

How to Increase Logical Volume Size on Linux

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Logical volumes (LV) are controlled by the belonging volume group (VG), so there must have some free space in the VG for LVs to increase. If there’s no free space in VG, you need to make some. Please feel free to refer the following post for further information.How to Increase Volume Group Size on Enterprise […]
EXT4

How to Increase Volume Group Size on Linux

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When we have space pressure on logical volumes (LV), we will seek for free space (or you may say unused space) in volume groups (VG) first. If there’s no free space left for increasing the size of LV, it’s time to add some physical volumes (PV) to the VG.Let’s check the VG and see what […]
Linux

How to Resolve PartProbe Error: “WARNING: the kernel failed to re-read the partition table on /dev/sda”

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In general, the newly created partition, i.e. /dev/sda3 in this case does not show in the device directory immediately and automatically.[root@test ~]# ll /dev/sd*brw-rw—-. 1 root disk 8, 0 Jul 11 19:30 /dev/sdabrw-rw—-. 1 root disk 8, 1 Jul 11 19:21 /dev/sda1brw-rw—-. 1 root disk 8, 2 Jul 11 19:21 /dev/sda2You have to either reboot […]
BIND

How to Configure BIND Named Service on Enterprise Linux 7

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Since we are running on CentOS 7.1 Minimal which has no default named service, so we need to install it either by yum install bind bind-utils or yum groupinstall “DNS Name Server”.[root@primary-dns ~]# yum -y install bind bind-utilsLoaded plugins: fastestmirrorLoading mirror speeds from cached hostfile * base: centos.cs.nctu.edu.tw * extras: centos.cs.nctu.edu.tw * updates: centos.cs.nctu.edu.twResolving Dependencies–> Running transaction check—> […]