Could not open file "pg_clog/0XXX"

I need to vacuum full the database but got this error

mydb=# vacuum full;
ERROR:  could not access status of transaction 376865319
DETAIL:  Could not open file "pg_clog/0167": No such file or directory.




Solution per searching google.

-bash-3.2$ dd if=/dev/zero of=/pgsql/data/pg_clog/0167 bs=256k count=1


Then VACCUM FULL again.

Fixing iscsi connectivity issue between Centos 6 and Compellent Storage

Fixing iscsi connectivity issue between Centos 6 and Compellent Storage


I boot a Centos 6 server so it can be mounted with a volume from compellent, but got this issue that the HBA interface cannot be detected at the compellent side but check the connectivity, it able to established connection to iscsi target.


I manually connect the host to the compellent server iscsi ip, so below, I have 8 IP to connect

#connecting
for i in 1 2 3 4 5 6 7 8; do iscsiadm --mode discoverydb --type sendtargets --portal 1.2.3.$i --discover; done

#logging in
iscsiadm -m node -l



#connecting
But i encountered at the compellent an issue where the existing initiator name does not show, so I cannot bind the volume to that said host at compellent.

The fix is to rename the initiator name. Use the command

/sbin/iscsi-iname


The above will generate a new name and then put it at /etc/iscsi/initiatorname.iscsi



If you have an existing InitiatorName=iqn.1994-05.com.redhat:fc5b3050bf

and that name either defined on different IP, you may replace that with the new name and restart iscsi service.

Then check at compellent the hba for the host IP equivalent, it should display the new name and the IP and you can now map the volume to the said server. 

sftp chroot environment - config and script

sftp chroot environment


Of course, sshd service should be enabled.


Sample Config:

#/etc/ssh/sshd_config
#
Protocol 2
SyslogFacility AUTHPRIV
MaxAuthTries 5
PubkeyAuthentication yes
PasswordAuthentication yes
ChallengeResponseAuthentication no
GSSAPIAuthentication yes
GSSAPICleanupCredentials yes
UsePAM yes
AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES
AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT
AcceptEnv LC_IDENTIFICATION LC_ALL
X11Forwarding yes
Ciphers aes128-ctr,aes192-ctr,aes256-ctr
MACs hmac-sha1,hmac-ripemd160
Subsystem       sftp    internal-sftp

Match Group sftpusers
        ChrootDirectory /home/sftpusers/%u
        ForceCommand internal-sftp
###EOF



Sample sftp adduser script

#/usr/local/sbin/sftp_adduser.sh
#!/bin/bash
#
if [ $# -lt 1 ]; then
        echo "Usage: `basename $0`" sftp username
        echo "   eg. `basename $0` "sftp_something
        exit 1
fi
RANPASS=`date +%s | sha256sum | base64 | head -c 8 ; echo`
USERNAME=$1
SFTPHOME=/home/sftpusers
SFTPSHELL=/usr/libexec/openssh/sftp-server

id $USERNAME 2> /dev/null 1>  /dev/null
if [ $? -eq 0 ]
then
echo "$1 already exist, please try again using another name"
exit

else
        useradd -d $SFTPHOME/$USERNAME -s $SFTPSHELL -p $RANPASS $USERNAME
        echo $RANPASS > /tmp/passwd.tmp001
        sleep 1
        passwd --stdin < /tmp/passwd.tmp001 $USERNAME
        echo $USERNAME >> /etc/listfile/sshusers

        #set permission
        usermod -g sftpusers $USERNAME
        usermod -G sftpusers $USERNAME

        #This is the default folder for sftp users
        mkdir $SFTPHOME/$USERNAME/FILES
     
        #set permissions
        chown root $SFTPHOME/$USERNAME
        chmod go-w $SFTPHOME/$USERNAME
        chown $USERNAME:sftpusers $SFTPHOME/$USERNAME/FILES
        chmod u+rwX $SFTPHOME/$USERNAME
        chmod 755 $SFTPHOME/$USERNAME
        chmod g+rx $SFTPHOME/$USERNAME

        #Details
        echo USER CREATED: $USERNAME
        echo USER DEFINED PASSWORD: $RANPASS
        echo FTP INTERNAL IP: 1.2.3.4
        echo FTP EXTERNAL IP: 111.222.112.221
        echo USER: $USERNAME has been created at ftp 1.2.3.4 | mail -s "created at sftp 1.2.3.4 on `date`" admin@myhost.com
fi