Category: Linux

chattr: Operation not supported while reading flags

Posted on October 27, 2021 (October 27, 2021) by ServerOk

When making a file immutable with chattr command, I get the following error

[root@vps784847 vhosts]# chattr +i serverok.in.conf 
chattr: Operation not supported while reading flags on serverok.in.conf
[root@vps784847 vhosts]#

[root@vps784847 vhosts]# chattr +i serverok.in.conf

chattr: Operation not supported while reading flags on serverok.in.conf

[root@vps784847 vhosts]#

The error was due to the file I was trying to chattr being a symlink, not a real file.

[root@vps784847 vhosts]# ls -la
total 0
drwxr-xr-x. 2 root root  31 Oct 27 08:11 .
drwxr-xr-x. 7 root root 131 Jun  1 02:03 ..
lrwxrwxrwx. 1 root root  51 Jul 24 12:39 serverok.in.conf -> /var/www/vhosts/system/serverok.in/conf/nginx.conf
[root@vps784847 vhosts]#

[root@vps784847 vhosts]# ls -la

total 0

drwxr-xr-x. 2 root root 31 Oct 27 08:11 .

drwxr-xr-x. 7 root root 131 Jun 1 02:03 ..

lrwxrwxrwx. 1 root root 51 Jul 24 12:39 serverok.in.conf -> /var/www/vhosts/system/serverok.in/conf/nginx.conf

[root@vps784847 vhosts]#

To fix the error, chattr the actual file.

chattr +i /var/www/vhosts/system/serverok.in/conf/nginx.conf

1	chattr +i /var/www/vhosts/system/serverok.in/conf/nginx.conf

[…]

mount: unknown filesystem type ‘LVM2_member’.

Posted on October 26, 2021 by ServerOk

When I try to mount a partition, I get the following error

[root@sysresccd ~]# mount /dev/nvme0n1p3 /mnt
mount: /mnt: unknown filesystem type 'LVM2_member'.
[root@sysresccd ~]#

[root@sysresccd ~]# mount /dev/nvme0n1p3 /mnt

mount: /mnt: unknown filesystem type 'LVM2_member'.

[root@sysresccd ~]#

This is because the disk is LVM. First of all identify the name of the volume group and logical volume.

vgs
lvs

vgs

lvs

Example

[root@sysresccd ~]# vgs
  VG #PV #LV #SN Attr   VSize  VFree
  vg   2   3   0 wz--n- <1.82t    0 
[root@sysresccd ~]# lvs
  LV   VG Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root vg -wi-a-----   1.80t                                                    
  swap vg -wi-a----- <15.69g                                                    
  tmp  vg -wi-a-----   1.00g                                                    
[root@sysresccd ~]#

[root@sysresccd ~]# vgs

VG #PV #LV #SN Attr VSize VFree

vg 2 3 0 wz--n- <1.82t 0

[root@sysresccd ~]# lvs

LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert

root vg -wi-a----- 1.80t

swap vg -wi-a----- <15.69g

tmp vg -wi-a----- 1.00g

[root@sysresccd ~]#

From the above result, we found the server has 3 logical volumes. The biggest volume is root. Other volumes […]

Delayed block allocation failed for inode

Posted on October 26, 2021 by ServerOk

On a CentOS server, reading files generated IO error. On /var/log/messages, I had the following error message

Oct 25 19:19:03 mta1 kernel: EXT4-fs error (device dm-0): ext4_wait_block_bitmap:520: comm kworker/u32:2: Cannot read block bitmap - block_group = 7705, block_bitmap = 252182537
Oct 25 19:19:03 mta1 kernel: EXT4-fs (dm-0): Delayed block allocation failed for inode 39976964 at logical offset 33810 with max blocks 14 with error 5
Oct 25 19:19:03 mta1 kernel: EXT4-fs (dm-0): This should not happen!! Data will be lost

Oct 25 19:19:03 mta1 kernel: EXT4-fs error (device dm-0): ext4_wait_block_bitmap:520: comm kworker/u32:2: Cannot read block bitmap - block_group = 7705, block_bitmap = 252182537

Oct 25 19:19:03 mta1 kernel: EXT4-fs (dm-0): Delayed block allocation failed for inode 39976964 at logical offset 33810 with max blocks 14 with error 5

Oct 25 19:19:03 mta1 kernel: EXT4-fs (dm-0): This should not happen!! Data will be lost

The problem is fixed by rebooting the server into rescue mode, then running the fsck command.

[root@sysresccd ~]# fsck -y /dev/vg/root
fsck from util-linux 2.35.2
e2fsck 1.45.6 (20-Mar-2020)
/dev/mapper/vg-root contains a file system with errors, check forced.
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Unconnected directory inode 61210647 (/var/cache/dnf/epel-modular-95d9a0c53e492cbd/???)
Connect to /lost+found? yes

Unconnected directory inode 61210656 (/var/cache/dnf/extras-2770d521ba03e231/???)
Connect to /lost+found? yes

Unconnected directory inode 61210668 (/var/cache/dnf/epel-6519ee669354a484/???)
Connect to /lost+found? yes

Pass 4: Checking reference counts
Inode 39845944 ref count is 1, should be 2.  Fix? yes

...
...
...

Unattached inode 61210637
Connect to /lost+found? yes

Inode 61210637 ref count is 2, should be 1.  Fix? yes

Inode 61210641 ref count is 3, should be 2.  Fix? yes

Directories count wrong for group #7474 (5, counted=0).
Fix? yes

Free inodes count wrong (120894192, counted=120894225).
Fix? yes

Padding at end of inode bitmap is not set. Fix? yes


/dev/mapper/vg-root: ***** FILE SYSTEM WAS MODIFIED *****
/dev/mapper/vg-root: 44271/120938496 files (2.2% non-contiguous), 235802671/483741696 blocks
[root@sysresccd ~]#

[root@sysresccd ~]# fsck -y /dev/vg/root

fsck from util-linux 2.35.2

e2fsck 1.45.6 (20-Mar-2020)

/dev/mapper/vg-root contains a file system with errors, check forced.

Pass 1: Checking inodes, blocks, and sizes

Pass 2: Checking directory structure

Pass 3: Checking directory connectivity

Unconnected directory inode 61210647 (/var/cache/dnf/epel-modular-95d9a0c53e492cbd/???)

Connect to /lost+found? yes

Unconnected directory inode 61210656 (/var/cache/dnf/extras-2770d521ba03e231/???)

Connect to /lost+found? yes

Unconnected directory inode 61210668 (/var/cache/dnf/epel-6519ee669354a484/???)

Connect to /lost+found? yes

Pass 4: Checking reference counts

Inode 39845944 ref count is 1, should be 2. Fix? yes

...

Unattached inode 61210637

Connect to /lost+found? yes

Inode 61210637 ref count is 2, should be 1. Fix? yes

Inode 61210641 ref count is 3, should be 2. Fix? yes

Directories count wrong for group #7474 (5, counted=0).

Fix? yes

Free inodes count wrong (120894192, counted=120894225).

Fix? yes

Padding at end of inode bitmap is not set. Fix? yes

/dev/mapper/vg-root: ***** FILE SYSTEM WAS MODIFIED *****

/dev/mapper/vg-root: 44271/120938496 files (2.2% non-contiguous), 235802671/483741696 blocks

[root@sysresccd ~]#

[…]

Set Static IP in RHEL 8 OVH VPS

Posted on October 22, 2021 by ServerOk

On OVH VPS running AlmaLinux 8, IPv4 IP address gets dropped. I have to connect to the server using KVM feature available in OVH control panel. I checked IP of the server with the command

ip a

ip a

It did hot show any IPv4 IP address. I checked the network configuration file

vi /etc/sysconfig/network-scripts/ifcfg-eth0

1	vi /etc/sysconfig/network-scripts/ifcfg-eth0

That had the following […]

Rocky Linux

Posted on October 21, 2021 by ServerOk

How to Convert CentOS 8 to Rocky Linux […]

How to Convert CentOS 8 to Rocky Linux

Posted on October 21, 2021 by ServerOk

You can convert your remote VPS or Dedicated Server running CentOS 8 to Rocky Linux easily by running the following commands.

dnf install wget
wget https://raw.githubusercontent.com/rocky-linux/rocky-tools/main/migrate2rocky/migrate2rocky.sh

1 2	dnf install wget wget https://raw.githubusercontent.com/rocky-linux/rocky-tools/main/migrate2rocky/migrate2rocky.sh

Now verify your system can be converted with command

bash migrate2rocky.sh -V

1	bash migrate2rocky.sh -V

If all is good, you can convert CentOS 8 to Rocky Linux with the command

bash migrate2rocky.sh -r

1	bash migrate2rocky.sh -r

[…]

AlmaLinux

Posted on October 20, 2021 by ServerOk

How to Migrate CentOS 8 to AlmaLinux […]

List contents of jks keystore file

Posted on October 19, 2021 (October 19, 2021) by ServerOk

To list the content of jks keystore file used by tomcat web server, run command

keytool -list -keystore FILE.jks

1	keytool -list -keystore FILE.jks

It will ask Keystore password. Once you enter the password, it will list the contents of the file. In the above keystore, there are 5 certificates with names inter, root1, root2, ssl_tomcat2, and tomcat. To get detailed information on […]

chattr: Operation not supported while reading flags

Checking NVMe Disk

mount: unknown filesystem type ‘LVM2_member’.

Delayed block allocation failed for inode

qdbus: not found

Set Static IP in RHEL 8 OVH VPS

Rocky Linux

How to Convert CentOS 8 to Rocky Linux

AlmaLinux

List contents of jks keystore file