2.1. escs¶

This machine is the main responsible of the running system and the most critical possible point of failure. It is its responsibility to:

run the ACS framework and the control system
export data via NFS

PARAMETER	VALUE
hardware	PC Tower
CPU	Intel(R) Quad Core(TM) i3 CPU 540 @ 3.07GHz
RAM	8GB
OS	Scientific Linux 5.3 i386 (32 bit)
Kernel	2.6.18-398.el5PAE
hostname	escs.noto.ira.inaf.it
eth1	192.167.187.17

2.1.1. OS installation¶

Escs is installed on a 2TB hard disk so partitioned:

[root@escs ~]# fdisk -l

Disco /dev/sda: 2000.3 GB, 2000398934016 byte

255 heads, 63 sectors/track, 243201 cylinders
Unità = cilindri di 16065 * 512 = 8225280 byte

Dispositivo Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1       63741   511999551   83  Linux
/dev/sda2           63742       65781    16386300   82  Linux swap / Solaris
/dev/sda3           65782      243201  1425126150   83  Linux

and:

[root@escs ~]# mount
/dev/sda1 on / type ext3 (rw)
/dev/sda3 on /archive type ext3 (rw)

2.1.2. Provisioning¶

Packages, users, groups and ACS are installed using BASIE provisioning scripts.

2.1.3. ACS Temporary Data¶

ACS needs to store log informations for each process running inside the system. this is true for every container, daemon, manager ecc... This files can be very large and sometimes they can flood the disk space resulting in wrong ACS behaviors, so we decided to store these files into a local directory on each machine:

[manager@escs ~] vim ~/.bashrc
...
export ACS_TMP=/data/ACSTMP

And we create the necessary directory setting owner and group to the ones used by ACS processes:

[manager@escs ~] cd /data
[manager@escs data/] mkdir ACSTMP
[manager@escs data/] chown manager:escs ACSTMP

2.1.4. NTP¶

Ntp service for system clock synchronization is configured via /etc/ntp.conf and /etc/ntp/ntpservers connecting to the station server 192.167.187.78:

[root@escs /]# mkdir /var/log/ntpstats
[root@escs /]# chown ntp:ntp /var/log/ntpstats
[root@escs /]# service ntpd start
[root@escs /]# chkconfig ntpd on

2.1.5. NFS¶

NFS is used in order to export archived data.

First, we create the exported filesystem directories:

[root@escs /]# mkdir /exports
[root@escs /]# mkdir /exports/archive

Then we bind the filesystem to the exported directories modifying the /etc/fstab file adding the following lines:

/archive                  /exports/archive           none    bind            0 0

Now the OS must be instructed to export the bound filesystems:

[root@escs /]# cat /etc/exports
/exports         192.167.187.0/24(rw,fsid=0,insecure,no_subtree_check,sync,no_root_squash)
/exports/archive    192.167.187.0/24(rw,nohide,insecure,no_subtree_check,sync,no_root_squash)
[root@escs /]# exportfs -rv

And we start the nfs server:

[root@escs /]# service nfs start
[root@escs /]# chkconf nfs on

2.1.6. DATA BACKUP¶

Data backup is realized on IRA-Bologna servers via rsync. we thus must authorize IRA server to use rsync service on escs which is the public access point of the control system and enable rsync service on the machine itself:

[root@escs /]# vim /etc/rsyncd.conf
[Area-Med-Arc]
    comment=archivio osservazioni single dish di Noto
    path=/archive/data
    read only = yes
    list = yes
    host allow =
    192.167.165.0/255.255.255.0
    uid = 3060
    gid = 335

[root@escs /]# vim /etc/xinetd.d/rsync
# default: off
# description: The rsync server is a good addition to an ftp server, as it \
#       allows crc checksumming etc.
service rsync
{
    disable = no
    socket_type     = stream
    wait            = no
    user            = root
    server          = /usr/bin/rsync
    server_args     = --daemon
    log_on_failure  += USERID
}

Service can be started and monitored using:

[root@escs /]# service xinted start|stop|status|restart