Memo

Grid The grid is the component responsable for Clustering in oracle. Grid (couche clusterware) -> ASM -> Disk Group - Oracle Restart = Single instance = 1 Grid (with or without ASM) - Oracle RAC OneNode = 2 instances Oracle in Actif/Passif with shared storage - Oracle RAC (Actif/Actif) SCAN 1# As oracle user: 2srvctl config scan 3 4SCAN name: host-env-datad1-scan.domain, Network: 1 5Subnet IPv4: 192.168.228.0/255.255.255.0/ens192, static 6Subnet IPv6: 7SCAN 1 IPv4 VIP: 192.168.228.33 8SCAN VIP is enabled. 9SCAN VIP is individually enabled on nodes: 10SCAN VIP is individually disabled on nodes: 11SCAN 2 IPv4 VIP: 192.168.228.35 12SCAN VIP is enabled. 13SCAN VIP is individually enabled on nodes: 14SCAN VIP is individually disabled on nodes: 15SCAN 3 IPv4 VIP: 192.168.228.34 16SCAN VIP is enabled. 17SCAN VIP is individually enabled on nodes: 18SCAN VIP is individually disabled on nodes: Oracle Instance resources: 1# As oracle user 2srvctl config database 3srvctl config database -d <SID> 4srvctl status database -d <SID> 5srvctl status nodeapps -n host-env-datad1n1 6srvctl config nodeapps -n host-env-datad1n1 7# ============ 8srvctl stop database -d DB_NAME 9srvctl stop database -d DB_NAME -o normal 10srvctl stop database -d DB_NAME -o immediate 11srvctl stop database -d DB_NAME -o transactional 12srvctl stop database -d DB_NAME -o abort 13srvctl stop instance -d DB_NAME -i INSTANCE_NAME 14# ============= 15srvctl start database -d DB_NAME -n host-env-datad1n1 16srvctl start database -d DB_NAME -o nomount 17srvctl start database -d DB_NAME -o mount 18srvctl start database -d DB_NAME -o open 19# ============ 20srvctl relocate database -db DB_NAME -node host-env-datad1n1 21srvctl modify database -d DB_NAME -instance DB_NAME 22srvctl restart database -d DB_NAME 23# === Do not do it 24srvctl modify instance -db DB_NAME -instance DB_NAME_2 -node host-env-datad1n2 25srvctl modify database -d DB_NAME -instance DB_NAME 26srvctl modify database -d oraclath -instance oraclath Cluster resources 1crs_stat 2crsctl status res 3crsctl status res -t 4crsctl check cluster -all 5 6# Example how it should look: 7/opt/oracle/grid/12.2.0.1/bin/crsctl check cluster -all 8************************************************************** 9host-env-datad1n1: 10CRS-4535: Cannot communicate with Cluster Ready Services 11CRS-4529: Cluster Synchronization Services is online 12CRS-4534: Cannot communicate with Event Manager 13************************************************************** 14host-env-datad1n2: 15CRS-4537: Cluster Ready Services is online 16CRS-4529: Cluster Synchronization Services is online 17CRS-4533: Event Manager is online 18************************************************************** 1show parameter cluster 2 3NAME TYPE VALUE 4------------------------------------ ----------- ------------------------------ 5cdb_cluster boolean FALSE 6cdb_cluster_name string DB_NAME 7cluster_database boolean TRUE 8cluster_database_instances integer 2 9cluster_interconnects string Stop/start secondary node: 1-- Prevent Database to switch over 2ALTER database cluster_database=FALSE; 1# as root 2/u01/oracle/base/product/19.0.0/grid/bin/crsctl stop crs -f 3/u01/oracle/base/product/19.0.0/grid/bin/crsctl disable crs 4 5# Shutdown/startup VM or other actions 6 7# as root 8/u01/oracle/base/product/19.0.0/grid/bin/crsctl enable crs 9/u01/oracle/base/product/19.0.0/grid/bin/crsctl start crs Stop/Start properly DB on both nodes: 1# as oracle user 2srvctl stop database -d oraclath 3 4# As root user, on both nodes: 5/opt/oracle/grid/12.2.0.1/bin/crsctl stop crs -f 6/opt/oracle/grid/12.2.0.1/bin/crsctl disable crs 7 8# As root user, on both nodes: 9/opt/oracle/grid/12.2.0.1/bin/crsctl enable crs 10/opt/oracle/grid/12.2.0.1/bin/crsctl start crs 11 12# checks after restart 13ps -ef | grep asm_pmon | grep -v "grep" 14 15# if ASM is up and running 16srvctl start database -d oraclath -node host1-env-data1n1.domain Listner issue 1# As oracle user 2srvctl status scan_listener 3 4PRCR-1068 : Failed to query resources 5CRS-0184 : Cannot communicate with the CRS daemon. the solution:

Checks your disks 1# check partion 2parted -l /dev/sda 3fdisk -l 4 5# check partition - visible before the mkfs 6ls /sys/sda/sda* 7ls /dev/sd* 8 9# give partition after the mkfs or pvcreate 10blkid 11blkid -o list 12 13# summary about the disks, partitions, FS and LVM 14lsblk 15lsblk -f Create Partition 1 on disk sdb in script mode 1# with fdisk 2printf "n\np\n1\n\n\nt\n8e\nw\n" | sudo fdisk "/dev/sdb" 3 4# with parted 5sudo parted /dev/sdb mklabel gpt mkpart primary 1 100% set 1 lvm on Gparted : interface graphique (ce base sur parted un utilitaire GNU - Table GPT)

The Basics mdadm (multiple devices admin) is software solution to manage RAID. It allow: create, manage, monitor your disks in an RAID array. you can the full disks (/dev/sdb, /dev/sdc) or (/dev/sdb1, /dev/sdc1) replace or complete raidtools Checks Basic checks 1# View real-time information about your md devices 2cat /proc/mdstat 3 4# Monitor for failed disks (indicated by "(F)" next to the disk) 5watch cat /proc/mdstat Checks RAID 1# Display details about the RAID array (replace /dev/md0 with your array) 2mdadm --detail /dev/md0 3 4# Examine RAID disks for information (not volume) similar to --detail 5mdadm --examine /dev/sd* Settings The conf file /etc/mdadm.conf does not exist by default and need to be created once you finish your install. This file is required for the autobuild at boot.

FS Types ext4 : the most widespread on GNU/Linux (derived from ext2 and ext3). It is journaled, meaning it records write operations to guarantee data integrity in case of an abrupt disk stop. It can also handle volumes up to 1 EiB (1024 PiB), and allows pre-allocating a contiguous area for a file to minimize fragmentation. Use this filesystem if you want to be able to read data back from macOS or Windows.

S.M.A.R.T. is a technology that allows you to monitor and analyze the health and performance of your hard drives. It provides valuable information about the status of your storage devices. Here are some useful commands and tips for using S.M.A.R.T. with smartctl: Display S.M.A.R.T. Information To display S.M.A.R.T. information for a specific drive, you can use the following command: 1smartctl -a /dev/sda This command will show all available S.M.A.R.T. data for the /dev/sda drive.

Install 1yum install iscsi-initiator-utils 2 3#Checks 4iscsiadm -m session -P 0 # get the target name 5iscsiadm -m session -P 3 | grep "Target: iqn\|Attached scsi disk\|Current Portal" 6 7# Discover and mount ISCSI disk 8iscsiadm -m discovery -t st -p 192.168.1.112 9iscsiadm --mode discovery --type sendtargets --portal 192.168.1.112 10 11# Login 12iscsiadm -m node -T iqn.1992-04.com.emc:cx.ckm00192201413.b0 -l 13iscsiadm -m node -T iqn.1992-04.com.emc:cx.ckm00192201413.b1 -l 14iscsiadm -m node -T iqn.1992-04.com.emc:cx.ckm00192201413.a1 -l 15iscsiadm -m node -T iqn.1992-04.com.emc:cx.ckm00192201413.a0 -l 16 17# Enable/Start service 18systemctl enable iscsid iscsi && systemctl stop iscsid iscsi && systemctl start iscsid iscsi Rescan BUS 1for BUS in /sys/class/scsi_host/host*/scan; do echo "- - -" > ${BUS} ; done 2 3sudo sh -c 'for BUS in /sys/class/scsi_host/host*/scan; do echo "- - -" > ${BUS} ; done ' Partition your FS

Install and Set Multipath 1yum install device-mapper-multipath Check settings in vim /etc/multipath.conf: 1defaults { 2user_friendly_names yes 3path_grouping_policy multibus 4} add disk in blacklisted and a block 1multipaths { 2 multipath { 3 wwid "36000d310004142000000000000000f23" 4 alias oralog1 5 } Special config for some providers. For example, recommended settings for all Clariion/VNX/Unity class arrays that support ALUA: 1 devices { 2 device { 3 vendor "DGC" 4 product ".*" 5 product_blacklist "LUNZ" 6 : 7 path_checker emc_clariion ### Rev 47 alua 8 hardware_handler "1 alua" ### modified for alua 9 prio alua ### modified for alua 10 : 11 } 12 } Checks config with: multipathd show config |more

The Basics list of component: PV (Physical Volume) VG (Volume Group) LV (Logical Volume) PE (Physical Extend) LE (Logical Extend) FS (File Sytem) LVM2 use a new driver, the device-mapper allow the us of disk´s sectors in different targets: - linear (most used in LVM). - stripped (stripped on several disks) - error (all I/O are consider in errors) - snapshot (allow snapshot async) mirror (integrate elements useful for the pvmove command) below example show you a striped volume and linear volume 1lvs --all --segments -o +devices 2server_xplore_col1 vgdata -wi-ao---- 21 striped 1.07t /dev/md2(40229),/dev/md3(40229),/dev/md4(40229),/dev/md5(40229),… 3server_xplore_col2 vgdata -wi-ao---- 1 linear 219.87g /dev/md48(0) Basic checks 1# Summary 2pvs 3vgs 4lvs 5 6# Scanner 7pvscan 8vgscan 9lvscan 10 11# Details info 12pvdisplay [sda] 13pvdisplay -m /dev/emcpowerd1 14vgdisplay [vg_root] 15lvdisplay [/dev/vg_root/lv_usr] 16 17# Summary details 18lvmdiskscan 19 /dev/sda1 [ 600.00 MiB] 20 /dev/sda2 [ 1.00 GiB] 21 /dev/sda3 [ 38.30 GiB] LVM physical volume 22 /dev/sdb1 [ <100.00 GiB] LVM physical volume 23 /dev/sdc1 [ <50.00 GiB] LVM physical volume 24 /dev/sdj [ 20.00 GiB] 25 1 disk 26 2 partitions 27 0 LVM physical volume whole disks 28 3 LVM physical volumes Usual Scenario in LVM Extend an existing LVM filesystem: 1parted /dev/sda resizepart 3 100% 2udevadm settle 3pvresize /dev/sda3 4 5# Extend a XFS to a fixe size 6lvextend -L 30G /dev/vg00/var 7xfs_growfs /dev/vg00/var 8 9# Add some space to a ext4 FS 10lvextend -L +10G /dev/vg00/var 11resize2fs /dev/vg00/var 12 13# Extend to a pourcentage and resize automaticly whatever is the FS type. 14lvextend -l +100%FREE /dev/vg00/var -r Create a new LVM filesystem: 1parted /dev/sdb mklabel gpt mkpart primary 1 100% set 1 lvm on 2udevadm settle 3pvcreate /dev/sdb1 4vgcreate vg01 /dev/sdb1 5lvcreate -n lv_data -l 100%FREE vg01 6 7# Create a XFS 8mkfs.xfs /dev/vg01/lv_data 9mkdir /data 10echo "/dev/mapper/vg01-lv_data /data xfs defaults 0 0" >> /etc/fstab 11mount -a 12 13# Create an ext4 14mkfs.ext4 /dev/vg01/lv_data 15mkdir /data 16echo "/dev/mapper/vg01-lv_data /data ext4 defaults 0 0" >> /etc/fstab 17mount -a Remove SWAP: 1swapoff -v /dev/dm-1 2lvremove /dev/vg00/swap 3vi /etc/fstab 4vi /etc/default/grub 5grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg 6grubby --remove-args "rd.lvm.lv=vg00/swap" --update-kernel /boot/vmlinuz-3.10.0-1160.71.1.el7.x86_64 7grubby --remove-args "rd.lvm.lv=vg00swap" --update-kernel /boot/vmlinuz-3.10.0-1160.el7.x86_64 8grubby --remove-args "rd.lvm.lv=vg00/swap" --update-kernel /boot/vmlinuz-0-rescue-cd2525c8417d4f798a7e6c371121ef34 9echo "vm.swappiness = 0" >> /etc/sysctl.conf 10sysctl -p Move data form disk to another: 1# #n case of crash, just relaunch pvmove without arguments 2pvmove /dev/emcpowerd1 /dev/emcpowerc1 3 4# Remove PV from a VG 5vgreduce /dev/emcpowerd1 vg01 6 7# Remove all unused PV from VG01 8vgreduce -a vg01 9 10# remove all PV 11pvremove /dev/emcpowerd1 mount /var even if doesn’t want: 1lvchange -ay --ignorelockingfailure --sysinit vgroot/var Renaming: 1# VG rename 2vgrename 3 4# LV rename 5lvrename 6 7# PV does not need to be rename LVM on partition VS on Raw Disk Even if in the past I was using partition MS-DOS disklabel or GPT disklabel for PV, I prefer now to use directly LVM on the main block device. There is no reason to use 2 disklabels, unless you have a very specific use case (like disk with boot sector and boot partition).

The Basics NFS vs iscsi NFS can handle simultaniously writing from several clients. NFS is a filesystem , iscsi is a block storage. iscsi performance are same with NFS. iscsi will appear as disk to the OS, not the case for NFS. Concurrent access to a block device like iSCSI is not possible with standard file systems. You’ll need a shared disk filesystem (like GFS or OCSFS) to allow this, but in most cases the easiest solution would be to just use a network share (via SMB/CIFS or NFS) if this is sufficient for your application.

Ressources 1# in crontab or tmux session - take every hour a track of the memory usage 2for i in {1..24} ; do echo -n "===================== " ; date ; free -m ; top -b -n1 | head -n 15 ; sleep 3600; done >> /var/log/SYSADM/memory.log &

Compare files 1diff <file1> <file2> # -w to ignore whitespace. 2colordiff <file1> <file2> # colourised diff. 3wdiff <file1> <file2> # word diff: [− −] replaced word, {+ +} added word. 4vimdiff <file1> <file2> # open both files in vim (blue = entirely different lines, red = partially different). 5fgrep -f <list> <file> # compare two lists (e.g. of hosts). Compare jar files 1diff -W200 -y <(unzip -vqq file1.jar | awk '{ if ($1 > 0) {printf("%s\t%s\n", $1, $8)}}' | sort -k2) <(unzip -vqq file2.jar | awk '{ if ($1 > 0) {printf("%s\t%s\n", $1, $8)}}' | sort -k2)

Find a process blocking a file with fuser: 1fuser -m </dir or /files> # Find process blocking/using this directory or files. 2fuser -cu </dir or /files> # Same as above but add the user 3fuser -kcu </dir or /files> # Kill process 4fuser -v -k -HUP -i ./ # Send HUP signal to process 5 6# Output will send you <PID + letter>, here is the meaning: 7# c current directory. 8# e executable being run. 9# f open file. (omitted in default display mode). 10# F open file for writing. (omitted in default display mode). 11# r root directory. 12# m mmap'ed file or shared library. with lsof ( = list open file): 1lsof +D /var/log # Find all files blocked with the process and user. 2lsof -a +L1 <mountpoint> # Process blocking a FS. 3lsof -c ssh -c init # Find files open by thoses processes. 4lsof -p 1753 # Find files open by PID process. 5lsof -u root # Find files open by user. 6lsof -u ^user # Find files open by user except this one. 7kill -9 `lsof -t -u toto` # kill user's processes. (option -t output only PID). MacGyver method: 1#When you have no fuser or lsof: 2find /proc/*/fd -type f -links 0 -exec ls -lrt {} \; AIX specifics (fuser) 1fuser -d /tmp # see the processes using the /tmp directory (AIX) 2fuser -c /your_FS # all processes with an open file in the filesystem (AIX) 3fuser -cu /dev/vg01/lvol5 # also search with a filesystem or an LV -c == -m ; -u also shows the process user. to kill the processes: fuser -kcu. File deleted but space still held For detecting deleted-but-still-open files (lsof +L1) and freeing the held space, see the Disk Cleanup page.