Day 4 Linux Fundamentals, Storage management

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      Disk Management in Linux | Managing Storage in RHEL 8 
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lsblk
fdisdk -l 
dmesg
lsscsi 			list SCSI devices (or hosts), list NVMe devices
lshw  			list hardware
cat /proc/scsi/scsi


save from data recovery
lsblk
badblocks -ws /dev/sda 


dd if=/dev/zero off=/dev/sda


lsblk
attach harddisk with your running system
lsblk 
now lest scan 
ls /sys/class/scsi_host/ | while read host; do echo "- - -" > /sys/class/scsi_host/$host/scan; done 
lsblk

for x in 'ls /sys/class/scsi_host/' | do echo "- - - - - $x Scaned- - - - -"; echo "- - -"> /sysclass/scsi_host/$x/scan; done 
fdisk -l /dev/sda
used only for MBR only 4 primary partation craeted

GPT disk 128
gpdisk usd for created GPR password 

cat /proc/partitions

Create PArtatiaon 
fdisk /dev/sda
n
p
1
Enter
+2G
t
8e
w
partbrobe
lsblk 

fdisk /dev/sda
n
p
1
Enter
+3G
w
partprobe
lsblk

fdisk -l /dev/sda
cat /proc/partitions


fdisk /dev/sda
n
e
Enter
1G
w
partprobe
lsblk
fdisk -l /dev/sda



For inster data in partation
mkdir Data
mount /dev/sda1 /Data
mkfs.xfs /dev/sda1
lsblk -f
mount /dev/sda1 /Data
df
cd /Data
touch test{a..z}
umount /dev/sda1 /Data
ls -ld  /dev/sda

mkdir test
mount /dev/sda1 /test

cd test 
ls


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      Filesystems & Mounting in Linux | Manage Filesystems in RHEL 8
-------------------------------------------------------------------------------------------------
man fs
cat /proc/filesystems
cat /etc/filesystems
man mount


lsblk
mke2fs /dev/sdb
blkid /dev/sdb
lsblk -f
tune2fs -l /dev/sdb |grep -i "block count"
incress brlock size
tune2fs -m10 /dev/sdb
tune2fs -l /dev/sdb |grep -i "block count"
cat /etc/fstab
df
mount 
cat /etc/mtab
lsblk -f
copy uuid
vi /etc/fstab
UUID=PAST /test  ext2 default 0 2

df
mount -a
df
man fstab
fsck /boot
umount /test
mount -t ext2 /dev/sdb /test/
df -Th
readonly mount 
mount -t ext2 -o ro /dev/sdb /test
mount |grep sdb
cat /etc/mtab | grep sdb
mount /dev/sdb
mount -t ext2 -o noexec /dev/sdb /test
mount |grep sdb
cat /etc/mtab | grep sdb
cp -r /sbin/ifconfig /test
cd test
ll
./ifconfig
umount /test
mount -t ext2 -o noacl /dev/sdb /test/
cat /etc/mtab | grep sdb
cd test 
touch a
setfacl -m u:zybi 7 a


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    Convert EXT2 Into EXT3 & EXT4 | Enable/Disable Journaling Feature
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lsblk
attach disk with VM
for x in 'ls /sys/class/scsi_host/' | do echo "- - - - - $x Scaned- - - - -"; echo "- - -"> /sysclass/scsi_host/$x/scan; done 
lsblk
fdisk /dev/sda
n
p
Enter
enter
w
partprobe
lsblk 
lsblk -f
mke2fs /dev/sda1
blkid
lablk -f
tune2fs -l /dev/sda1 | grep feature
mkdir test 
mount /dev/sda1 /test
df -hT
cd test
touch test{1..20}
cal > cal.txt
cd

Convert EXT2 to EXT3
umount /test
df -Th
tune2fs -j /dev/sda1
blkid /dev/sda1
tune2fs -l /dev/sda1 | grep feature
mount /dev/sda1 /test
cd test
cat cal


Convert EXT3 to EXT4
umount /test
df -Th
tune2fs -O extents,uninits_bg,dir_index /dev/sda1
blkid /dev/sda1
lsblk -f
mount /dev/sda1 /test
ll
cat cal.txt

Journaling Feature enable or disable 

tune2fs -l /dev/sda1 | grep feature
umount /test
tune2fs -O ^has_journal  /dev/sda1
tune2fs -l /dev/sda1 | grep feature
Enable Journaling 
tune2fs -O has_journal  /dev/sda1
tune2fs -l /dev/sda1 | grep feature


Mounting 
vi etc/fstab