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...

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...

FS Types ext4 : le plus répandu sous GNU/Linux (issu de ext2 et ext3). Il est journalisé, c’est à dire qu’il trace les opérations d’écriture pour garantir l’intégrité des données en cas d’arrêt brutal du disque. De plus, il peut gérer des volumes de taille jusque 1 024 pébioctets et permet la pré-allocation d’une zone...

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....

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...

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...

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....

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 & Hardware Logs Health Checks

Compare staffs Compare two 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)