mdadm (multiple devices admin) is software solution to manage RAID.
It allow:
/dev/sdb, /dev/sdc) or (/dev/sdb1, /dev/sdc1)raidtools1# 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
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*
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.
SshFS sert à monter sur son FS, un autre système de fichier distant, à travers une connexion SSH, le tout avec des droits utilisateur. L’avantage est de manipuler les données distantes avec n’importe quel gestionnaire de fichier (Nautilus, Konqueror, ROX, ou même la ligne de commande).
- Pre-requis : droits d'administration, connexion ethernet, installation de FUSE et du paquet SSHFS.
- Les utilisateurs de sshfs doivent faire partie du groupe fuse.
Rq : FUSE permet à un utilisateur de monter lui-même un système de fichier. Normalement, pour monter un système de fichier, il faut être administrateur ou que celui-ci l’ait prévu dans « /etc/fstab » avec des informations en dur.
First Install samba and samba-client (for debug + test)
/etc/samba/smb.conf1[home]
2Workgroup=WORKGROUP (le grp par defaul sur windows)
3Hosts allow = ...
4[shared]
5browseable = yes
6path = /shared
7valid users = user01, @un_group_au_choix
8writable = yes
9passdb backend = tdbsam #passwords are stored in the /var/lib/samba/private/passdb.tdb file.
testparm
/usr/bin/testparm -s /etc/samba/smb.conf
smbclient -L \192.168.56.102 -U test : list all samba shares available
smbclient //192.168.56.102/sharedrepo -U test : connect to the share
pdbedit -L : list user smb (better than smbclient)
NFS vs iscsi
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.
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 contiguë pour un fichier, afin de minimiser la fragmentation. Utilisez ce système de fichiers si vous comptez pouvoir relire des informations depuis votre Mac OS X ou Windows.
Preserve files permissions and ownership.
The Basic
1# Archive
2tar cvf mon_archive.tar <fichier1> <fichier2> </rep/doosier/>
3
4## Archive and compress with zstd everything in the current dir and push to /target/dir
5tar -I zstd -vcf archive.tar.zstd -C /target/dir .
6
7# Extract
8tar xvf mon_archive.tar
9
10# Extract push to target dir
11tar -zxvf new.tar.gz -C /target/dir
Other usefull options • t : list archive’s content. • T : Archive list given by a file. • P : Absolute path is preserve (usefull for backup /etc) • X : exclude • z : compression Gunzip • j : compression Bzip2 • J : compression Lzmacd
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
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)
list of component:
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)
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)
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
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
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
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
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
/var even if doesn’t want:1lvchange -ay --ignorelockingfailure --sysinit vgroot/var
1# VG rename
2vgrename
3
4# LV rename
5lvrename
6
7# PV does not need to be rename
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).
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:
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.
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 192.168.40.112
9iscsiadm --mode discovery --type sendtargets --portal 192.168.40.112
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
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
1yum install device-mapper-multipath
vim /etc/multipath.conf:1defaults {
2user_friendly_names yes
3path_grouping_policy multibus
4}
1multipaths {
2 multipath {
3 wwid "36000d310004142000000000000000f23"
4 alias oralog1
5 }
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