Showing posts from August, 2022

How to increase more space in root filesystem?

Firstly - make sure you have additional unpartitioned storage. Then: Use  fdisk  to create new partition (safer than expanding existing one) Use  pvcreate  to create physical LVM volume: pvcreate /dev/sdxx Use  vgextend  to extend existing LVM group using new physical volume: vgextend groupname /dev/sdxx You can get group names with  vgdisplay Use  lvextend  on lvm mapper to expand lvm volume: lvextend -l +100%FREE /dev/mapper/xxx Grow the filesystem: xfs_growfs /dev/mapper/xxx Or resize2fs /dev/mapper/xxx [root@shsdbdr01 ~]# df -h Filesystem             Size  Used Avail Use% Mounted on /dev/mapper/rhel-root  8.0G  7.9G  106M  99% / devtmpfs               966M     0  966M   0% /dev tmpfs                  982M     0  982M   0% /dev/shm tmpfs                  982M   11M  972M   2% /run tmpfs                  982M     0  982M   0% /sys/fs/cgroup /dev/sda1             1014M  179M  836M  18% /boot tmpfs                  197M  4.0K  197M   1% /run/user/42 /dev/sdc1              9.8G   36M  9

How to Mount an NFS File System (mount Command)

 Become superuser or assume an equivalent role. Create a mount point for the file system to be mounted, if necessary. # mkdir /mount-point There must be a mount point on the local system to mount a file system. A mount point is a directory to  which the mounted file system is attached. Ensure that the resource (file or directory) is available from a server. To mount an NFS file system, the resource must be made available on the server by using the share command.  For information on how to share resources, see About the NFS Service in System Administration Guide: Network Services. Mount the NFS file system. # mount -F nfs [-o mount-options] server:/directory /mount-point -o mount-options Specifies mount options that you can use to mount an NFS file system.  server:/directory Specifies the server's host name that contains the shared resource, and the path to the file or directory to mount. # mount -F nfs [-o mount-options] server:/directory /mount-point Specifies the directory on whi

Adding Swap Space on a Linux System

Unable to allocate physical memory during WLS start will be resolved by adding more SWAP space as below: Become a superuser (root) by typing: % su Password: root-password Create a file in a selected directory to add swap space by typing: dd if=/dev/zero of=/ dir / myswapfile bs=1024 count =number_blocks_needed where  dir  is a directory in which you have permission to add swap space. The  myswapfile  is the name of the swap file you are creating. The  number_blocks_needed  is an amount of 1024-byte blocks you want to create. See the  dd (1) man page for more information. Verify that the file was created by typing: ls -l / dir / myswapfile The new file appears in the directory. Initialize the new swap area by typing: mkswap / dir / myswapfile See the  mkswap (8) man page for more detailed information. Run the  swapon  command to enable the new swap space for paging and swapping by typing the following: swapon -a / dir / myswapfile Verify that the extra swap space was added by typing:

Virtual machine reports a "BUG: soft lockup"

  Issue Virtual machine guest suffers multiple soft lockups at the same time We are experiencing kernel panic due to softlockup. Logs show messages like (examples from different sources): Cause: kernel messages informing that vCPU did not get execution for N seconds Resolution Under normal circumstances, these messages may go away if the load decreases. This 'soft lockup' can happen if the kernel is busy, working on a massive amount of objects which need to be scanned, freed, or allocated, respectively. The stack traces of those tasks can give a first idea about what the tasks were done. However, to be able to examine the cause behind the messages, a kernel dump would be needed. While  these messages  cannot be disabled entirely, in some situations, increasing the time before these soft lockups are fired can relax the situation.   To do so, increase the following sysctl parameter: kernel.watchdog_thresh   The default value for this parameter is 10 and double the matter might be

Some useful SRVCTL commands

 STOP DATABASE  srvctl stop database -d db_name [-o stop_options] where stop_options is normal/immediate(default)/transactional/abort   srvctl stop database -d TANSID -o normal srvctl stop database -d TANSID -o immediate srvctl stop database -d TANSID -o transactional srvctl stop database -d TANSID -o abort START DATABASE srvctl start database -d db_name [-o start_options] where start_option is nomount/mount/open(default) srvctl start database -d TANSID -o nomount srvctl start database -d TANSID -o mount srvctl start database -d TANSID -o open STOP AN INSTANCE srvctl stop instance -d db_unique_name [-i “instance_name_list”]} [-o stop_options] [-f] srvctl stop instance -d TANSID -i TANSID1 START AN INSTANCE srvctl start instance -d db_unique_name [-i “instance_name_list”} [-o start_options] srvctl start instance -d TANSID -i TANSID1 REMOVING DB FROM CRS srvctl remove database -d db_unique_name [-f] [-y] [-v] srvctl remove database -d TANSID -f -y ADDING DB IN CRS srvctl add database -d

ORA-15260: Permission Denied On ASM Disk Group

You are running an ASM command and getting ORA-15260 SQL> conn / as sysdba Connected. SQL> create diskgroup <DISKGROUP> external redundancy disk '/dev/sda10','/dev/sda11'; create diskgroup <DISKGROUP> external redundancy disk '/dev/sda10','/dev/sda11' * ERROR at line 1: ORA-15260: permission denied on ASM disk group Cause: You have logged in with SYSDBA privilege, which is not allowed for ASM operations SQL> conn / as sysdba Connected. SQL> create diskgroup <DISKGROUP> external redundancy disk '/dev/sda10','/dev/sda11'; create diskgroup <DISKGROUP> external redundancy disk '/dev/sda10','/dev/sda11' * ERROR at line 1: ORA-15260: permission denied on ASM disk group Fix: Login with SYSASM credentials for ASM operations SQL> alter diskgroup REDO mount; alter diskgroup REDO mount * ERROR at line 1: ORA-15032: not all alterations performed ORA-15260: permission denied on ASM disk group SQL&