How to Reset root password in Proxmox VE 7

First, boot the system in the rescue kernel. I am assuming your boot partition is separated then the home partition, like in my case. Here are the list of commands I have used:

# mount /dev/md126 /mnt
# mount /dev/md127 /mnt/boot
# mount --bind /dev /mnt/dev
# mount --bind /dev/pts /mnt/dev/pts
# mount --bind /proc /mnt/proc
# mount --bind /sys /mnt/sys
# chroot /mnt
# passwd

Now, make sure to reset the password properly. Once done. Umount all the partition and boot in regular mode:

# umount /mnt/boot
# umount /mnt/sys
# umount /mnt/proc
# umount /mnt/dev/pts
# umount /mnt/dev
# umount /mnt
# reboot

It should be it.

How to Mount qcow2 KVM/Xen/VMware VM Image

To mount qcow2, you need to mount this image as a ‘Network Block Device’.

First, enable NBD

modprobe nbd max_part=8

Now, connect the qcow2 as an NBD device

qemu-nbd --connect=/dev/nbd0 /vz/vmprivate/v1002/harddisk.hdd

Now to mount the partition, first detect the partition

fdisk /dev/nbd0 -l

Now, you may mount the partition

mount /dev/nbd0p1 /mnt

Once, all the jobs are done, you may unmount, disconnect, and remove the NBD kernel module

umount /mnt
qemu-nbd --disconnect /dev/nbd0
rmmod nbd

KVM VM Not starting – could not get access to acl tech driver ‘ebiptables’


KVM VM not starting with the following error when you try to start:

could not get access to acl tech driver 'ebiptables'

There is a nwfilter module for libvirt. If for some reason, it comes up with an issue, the above error would appear. To fix this, you need to update (If any update is available) / reinstall (If no update is available) the following module using Yum:


The command would be like the following:

yum update libvirt-daemon-config-nwfilter

That shall fix the issue.

Server Error! (Ok) Roundcube Cpanel – Fix

When I tried to load my Roundcube today, found that it failed to load the inbox and instead had thrown the following error:

Server Error! (Ok)

Then, I tried searching the cpanel logs or the roundcube error log but found nothing. Then, I checked the Dovecot log located here:


I found the following:

May  7 13:57:49 network2 dovecot: imap([email protected])<26343><cQG+qxX7MvdneMrv>: Error: Mailbox INBOX: mmap(size=351817308) failed with file /home/mellow/mail/ Cannot allocate memory

This is happening because Dovecot caches the mail index in a file, once it tries to cache a lot of emails, it fails with a memory error. In those cases, you may remove the cache file and let Dovecot generate a new cache based on the latest mails. You may simply rm the file and see Roundcube is loading again:

rm -f /home/mellow/mail/

How to see all the constraints in a Postgresql Database

To see/list the constraints, first, connect to the database using the following:

\c my_prod;

Here we are assuming the database name is my_prod. Please note, we are putting these commands in the psql client utility.

Now, use the following query to list all the constraints in the database:

select pgc.conname as constraint_name,
       ccu.table_schema as table_schema,
from pg_constraint pgc
         join pg_namespace nsp on nsp.oid = pgc.connamespace
         join pg_class  cls on pgc.conrelid = cls.oid
         left join information_schema.constraint_column_usage ccu
                   on pgc.conname = ccu.constraint_name
                       and nsp.nspname = ccu.constraint_schema
order by pgc.conname;

Good luck

How to install SSL in Zimbra with Certificate and CA-bundle

There are 3 things you need:

  1. Private key
  2. Certificate
  3. Ca-bundle

First, switch to the user zimbra:

su - zimbra

Let’s except your files are located here:

Private Key: /tmp/private.key
Certificate: /tmp/
Ca-Bundle: /tmp/

Now, copy your private key file to the following location:

cp /tmp/private.key /opt/zimbra/ssl/zimbra/commercial/commercial.key

Now, first, verify 3 things to make sure, they are correct:

/opt/zimbra/bin/zmcertmgr verifycrt comm /opt/zimbra/ssl/zimbra/commercial/commercial.key /tmp/ /tmp/

If it, says ok, now you may deploy the certificate like the following:

/opt/zimbra/bin/zmcertmgr deploycrt comm /tmp/ /tmp/

Once done, now, exit from the user zimbra and restart zimbra:

service zimbra restart

Your SSL should work now.

How to stop Postgresql when you have multiple versions of PGSQL Running on Ubuntu

Question: How to stop Postgresql when you have multiple versions of PGSQL Running on Ubuntu

You may run the following command to stop specific version of postgresql when using multiple versions of postgresql in a single system, under Ubuntu

systemctl stop postgresql[@version-main]

So, for example, if you have a system, with 3 postgresql server, 12, 14, 15, and would like to stop 14 and 15, then you can run the following:

systemctl stop postgresql@15-main
systemctl stop postgresql@14-main

To disable them from booting:

systemctl disable postgresql@15-main
systemctl disable postgresql@14-main

How to mount NTFS in Debian/Ubuntu

You need to first install NTFS-3G package to access NTFS on Debian. NTFS-3g depends on libntfs and fuse. Using the following shall install NTFS-3g on the system:

apt install ntfs-3g -y

Once done, now you can mount ntfs using the following command:

mount -t ntfs /dev/sdb2 /mnt

In this case, sdb2 is the ntfs partition, and we are mounting this to /mnt directory.

If you are trying to mount a Windows 10/11 partition, you might end up having a read only NTFS file system. The reason is Windows 10/11 partition doesn’t fully shutdown on shutdown command, instead it hibernates the system. To properly shutdown the system, remember to shutdown the system with ‘SHIFT’ + SHUTDOWN.

ipset: error while loading shared libraries: cannot open shared object file: No such file or directory


When you try to install Imunify360, you get the following:

[root@stack10 ~]# bash IPL
Checking for an update to
Downloading (please wait) is already the latest version (2.58) - continuing
Detecting ostype... centos
ipset: error while loading shared libraries: cannot open shared object file: No such file or directory
[2022-12-21 04:44:14] Your OS virtualization technology kvm has limited support for ipset in containers. Please, contact Imunify360 Support Team.

The reason is, latest Imunify360 installer looking for the ipset library. To install that, use the following:

yum install ipset-libs -y

Once done, you should be able to install Imunify360 now.

Could not make the Query. Virtualizor Error

Today, when I opened a Virtualizor panel for a VM node, I found an issue like the following:

Could not make the Query.
SELECT tasks.actid, tasks.action, users.uid, FROM `tasks` LEFT JOIN users on tasks.uid = users.uid WHERE action NOT IN ('vpsbackups_plan_email', 'send_background_mail', 'backuply_vpsbackups_plan_email') ORDER BY tasks.actid DESC LIMIT 10
    [0] => HY000
    [1] => 144
    [2] => Table './virtualizor/tasks' is marked as crashed and last (automatic?) repair failed

Issue was the tasks table is marked as crashed. To solve this, we need to repair the table tasks.

First, find the password for database ‘virtualizor’ using the following command:

[root@sg40 ~]# grep dbpass /usr/local/virtualizor/universal.php
$globals['dbpass'] = 'gziqr4y989';

Now connect to the mysql using the password:

/usr/local/emps/bin/mysql -u root -p virtualizor

Now repair the table:

use virtualizor;

Now the virtualizor shall work.