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Ansil4Linux Blog Moving to new site https://linxlabs.com/

I've been studying new topics for some time and decided to start a new website

Site is now live and can be accessed at https://linxlabs.com/

Many articles were already posted on "Golang"

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LVM thin provisioning - file system usage and pool usage dosn't match

When I was demonstrating LVM thin provisioning to new batch of campus hires ; they pointed out an important mismatch between thin pool usage and actual file system usage.

I thought , it would be worthy to give it a try to find the cause.

So here we go; I created a thin pool with size of 100MB and thin volume of 1GB

Thin volume formatted with ext4 and mounted over /test_fs

Everything was going smooth as per the plan until we did a tar backup of /usr over /test_fs.

Here we go ;

* Created vg001 - size 12GB

[root@ol7-san ~]# vgdisplay vg001   --- Volume group ---   VG Name               vg001   System ID   Format                lvm2   Metadata Areas        1   Metadata Sequence No  12   VG Access             read/write   VG Status             resizable   MAX LV                0   Cur LV                0   Open LV               0   Max PV                0   Cur PV                1   Act PV                1   VG Size               12.00 GiB   PE Size               4.00 MiB   Total PE              3071   Allo…
SFTP auto login without keys / without password

sftp command doesn't have option to specify password for auto login.

Recently faced this issue while writing a script on SUSE Linux for transferring system performance report to a central location, which is also a SuSE system.

We can accomplish this with "lftp" or "expect" command, but SLES doesn't install those binaries default.

I've to live with what I got, so let’s try how we can accomplish this with sftp command.


The idea is

1.Set "SSH_ASKPASS" environment variable and force "sftp" command to read password from there.

2."sftp" will always ask password if its executing from a terminal, so we need to daemonize sftp command with "setsid" command


Below code snippets will give some idea how we get it to the solution

pathnames.h

/* Default path to ASKPASS program */

#define _PATH_SSH_ASKPASS_DEFAULT   "/usr/X11R6/bin/ssh-askpass"

ssh.h

/*
 * Environment vari…

Linux OS backup and Restoration using ReaR – Relax & Recover

ReaR – Relax and Recover is an Opensource tool for backing up your OS. The Physical to Virtual and Virtual to Physical migration of OS is also possible with ReaR You can also integrate your favorite backup tools like IBM TSM or HP Data Protector with ReaR to backup the OS to External Storage
Here is the setup I used
OS :openSuSE 11.4 ReaR package: rear-1.10.0-23.1.noarch Pre-requisites 1: RPMs mingetty binutils iputils tar gzip ethtool syslinux iproute2 lsb genisoimage nfs-client rpcbind rpmlib(PayloadFilesHavePrefix) <= 4.0-1 rpmlib(CompressedFileNames) <= 3.0.4-1 /bin/bash rpmlib(PayloadIsLzma) <= 4.4.6-1
Pre-requisite 2: NFS server ( I used RHEL5 )with a share /rear/backup and the share must have write permission /etc/exports /rear/backup*(rw,no_root_squash) service nfs start showmount –e ---------------------------------------------- If yor NFS server is already running, then Add “/rear/backup*(rw,no_root_squash)” to /etc/exports exportfs –a showmount –e
The main configuration file is /etc…

HMC vtmenu exit

You can exit the cosole of an LPAR ,that has been taken using HMC vtmenu ,by typing
"~." (press dot key after tild without qoutes )

If you had taken HMC vtmenu using SSH ,your ssh connection to HMC will alse loses.

Read /etc/passwd using TFTP venerability - How to resolve in AIX

1.vi /etc/tftpaccess.ctl allow:/tftpboot
Save the file You are done..!!! Now the clients can only access /tftpboot using TFTP

FTP Banner in AIX

1.vi /etc/ftpaccess.ctl
herald: /path/to/banner/file ---->Enter your welcome message in this file motd: on
2.refresh -s inted

You are done