RHEL 6- loop devices

If you need to mount a lot of ISOs on a system than you could run into the problem, that you do not have free loop devices left.
There are several solutions from running “MAKEDEV -v /dev/loop” at boot time (e.g. add it to rc.local) to creating a file called loop.conf at /etc/modprobe.d/ and inserting the follwoing line:

At the end the following parameter has to be added to the Grub-config file:

max_loop=128

# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,0)
#          kernel /vmlinuz-version ro root=/dev/mapper/vg1-root
#          initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
password --encrypted ******************************************************************
title Red Hat Enterprise Linux 6 (2.6.32-504.el6.x86_64)
        root (hd0,0)
        kernel /vmlinuz-2.6.32-504.el6.x86_64 ro root=/dev/mapper/vg1-root rd_NO_LUKS LANG=en_US.UTF-8  KEYBOARDTYPE=pc KEYTABLE=de-latin1-nodeadkeys rd_NO_MD rd_LVM_LV=vg1/root SYSFONT=latarcyrheb-sun16 rd_LVM_LV=vg1/swap crashkernel=auto rd_NO_DM max_loop=128
        initrd /initramfs-2.6.32-504.el6.x86_64.img

instead of makedev (which creates 264 loop devices) the following snipped can be used:

 

mknod -m640  /dev/loop8  b 7  8
mknod -m640  /dev/loop9 b 7  9
mknod -m640  /dev/loop10 b 7  10
mknod -m640  /dev/loop11 b 7  11
mknod -m640  /dev/loop12 b 7  12
mknod -m640 /dev/loop13 b 7 13
mknod -m640 /dev/loop14 b 7 14
mknod -m640 /dev/loop15 b 7 15
mknod -m640 /dev/loop16 b 7 16
mknod -m640 /dev/loop17 b 7 17
mknod -m640 /dev/loop18 b 7 18
mknod -m640 /dev/loop19 b 7 19
mknod -m640 /dev/loop20 b 7 20
mknod -m640 /dev/loop21 b 7 21
mknod -m640 /dev/loop22 b 7 22
mknod -m640 /dev/loop23 b 7 23
mknod -m640 /dev/loop24 b 7 24
mknod -m640 /dev/loop25 b 7 25
mknod -m640 /dev/loop26 b 7 26
mknod -m640 /dev/loop27 b 7 27
mknod -m640 /dev/loop28 b 7 28
mknod -m640 /dev/loop29 b 7 29
mknod -m640 /dev/loop30 b 7 30
mknod -m640 /dev/loop31 b 7 31
mknod -m640 /dev/loop32 b 7 32
mknod -m640 /dev/loop33 b 7 33
mknod -m640 /dev/loop34 b 7 34
mknod -m640 /dev/loop35 b 7 35
mknod -m640 /dev/loop36 b 7 36
mknod -m640 /dev/loop37 b 7 37
mknod -m640 /dev/loop38 b 7 38
mknod -m640 /dev/loop39 b 7 39
mknod -m640 /dev/loop40 b 7 40
mknod -m640 /dev/loop41 b 7 41
mknod -m640 /dev/loop42 b 7 42
mknod -m640 /dev/loop43 b 7 43
mknod -m640 /dev/loop44 b 7 44
mknod -m640 /dev/loop45 b 7 45
mknod -m640 /dev/loop46 b 7 46
mknod -m640 /dev/loop47 b 7 47
mknod -m640 /dev/loop48 b 7 48
mknod -m640 /dev/loop49 b 7 49
mknod -m640 /dev/loop50 b 7 50
mknod -m640 /dev/loop51 b 7 51
mknod -m640 /dev/loop52 b 7 52
mknod -m640 /dev/loop53 b 7 53
mknod -m640 /dev/loop54 b 7 54
mknod -m640 /dev/loop55 b 7 55
mknod -m640 /dev/loop56 b 7 56
mknod -m640 /dev/loop57 b 7 57
mknod -m640 /dev/loop58 b 7 58
mknod -m640 /dev/loop59 b 7 59
mknod -m640 /dev/loop60 b 7 60
mknod -m640 /dev/loop61 b 7 61
mknod -m640 /dev/loop62 b 7 62
mknod -m640 /dev/loop63 b 7 63
mknod -m640 /dev/loop64 b 7 64
chown root:disk /dev/loop*

 

Sync Redhat repositories to a local deployment server [RHEL6/7]

Redhat offers a great tool with Redhat satellite server especially with Satellite 6.  But the price is quite high, and if you need to provides packages and updates to multiple separated environments it’s out of the picture.
(For those who are interessted – Katello is the upstream project of Redhat’s Satellite 6).

So the question is now, how to get the the Redhat repos to your deployment server.
First a subscription is needed and only channels/repos included in this subscription can be synchronized.
If we have the channels/repos availalbe on our system which we want to use to sync we can use reposync to pull all the repositoriers from the internet.
The follwoing example shows a list of repositories which are available on my machine:

[root@server~]# yum repolist
Loaded plugins: downloadonly, refresh-packagekit, rhnplugin, security
This system is receiving updates from RHN Classic or RHN Satellite.
repo id                                    repo name                                                          status
epel                                       Extra Packages for Enterprise Linux 6 - x86_64                     11,588
rhel-x86_64-server-6                       Red Hat Enterprise Linux Server (v. 6 for 64-bit x86_64)           14,872
rhel-x86_64-server-6-rhscl-1               Red Hat Software Collections 1 (RHEL 6 Server x86_64)               3,003
rhel-x86_64-server-dts-6                   Red Hat Developer Toolset (for RHEL 6 Server for x86_64)               84
rhel-x86_64-server-dts2-6                  Red Hat Developer Toolset 2 (for RHEL 6 Server for x86_64)            469
rhel-x86_64-server-extras-6                RHEL Server Extras (v. 6 for 64-bit x86_64)                            17
rhel-x86_64-server-ha-6                    RHEL Server High Availability (v. 6 for 64-bit x86_64)                423
rhel-x86_64-server-optional-6              RHEL Server Optional (v. 6 64-bit x86_64)                           8,313
rhel-x86_64-server-rh-common-6             Red Hat Common (for RHEL 6 Server x86_64)                              59
rhel-x86_64-server-supplementary-6         RHEL Server Supplementary (v. 6 64-bit x86_64)                        514
repolist: 39,342
[root@server~]#
Available channels

 

The easiest way to sync a repo is to just call the following command:

reposync -p /path/to/storeage/dir/RHserv6-general_64/ --repoid=rhel-x86_64-server-6 -l
Sync repos

Important is to add the -l option to the command. The command enables the yum-plugins and to be able to sync directly from Redhat those plugins have to be enabeld!

But I think the most people don’t want to run the synchronization by hand and some metadata also would be nice – so you can use/adapt the following script and add it as a cronjob.

	#!/bin/bash
############################################################################
#
#       @Author: fweixelb@fawcs.info
#
#       @Description:
#               Script synchronizes the RH-repos
#
###########################################################################


datetime=$(date +"%F_%T")

#General
reposync -p /path/to/storeage/dir/RHserv6-general_64/ --repoid=rhel-x86_64-server-6 -l --download-metadata > /var/log/reposync/general_$datetime.log
compsfile=$(echo "$(ls -d /path/to/storeage/dir/RHserv6-general_64/* | grep rhel)/comps.xml")
createrepo /path/to/storeage/dir/RHserv6-general_64/ -g $compsfile --update

#Common
reposync -p /path/to/storeage/dir/RHserv6-common_64/ --repoid=rhel-x86_64-server-rh-common-6 -l --download-metadata > /var/log/reposync/common_$datetime.log
compsfile=$(echo "$(ls -d /path/to/storeage/dir/RHserv6-common_64/* | grep rhel)/comps.xml")
createrepo /path/to/storeage/dir/RHserv6-common_64/ -g $compsfile --update

#Optional
reposync -p /path/to/storeage/dir/RHserv6-optional_64/ --repoid=rhel-x86_64-server-optional-6 -l --download-metadata > /var/log/reposync/optional_$datetime.log
compsfile=$(echo "$(ls -d /path/to/storeage/dir/RHserv6-optional_64/* | grep rhel)/comps.xml")
createrepo /path/to/storeage/dir/RHserv6-optional_64/ -g $compsfile --update

#rhel Software Collection
reposync -p /path/to/storeage/dir/RHserv6-rhscl_64/ --repoid=rhel-x86_64-server-6-rhscl-1 -l --download-metadata > /var/log/reposync/scl_$datetime.log
compsfile=$(echo "$(ls -d /path/to/storeage/dir/RHserv6-rhscl_64/* | grep rhel)/comps.xml")
createrepo /path/to/storeage/dir/RHserv6-scl_64/ -g $compsfile --update
automated sync script

So, what does this script do?
Because it’s intended to be used as a cronjob it logs the sync-process to /var/log/reposync – I don’t do any logrotation because the files are quite small and the cronjobs runs only once a week – so there is not too much space used by the logfiles and I clean them from hand. but if its ran more often you should think about log rotation.

Reposync itself creates a subfolder in the spceified directory which is named like the repoid and contains the metadata (comps & updateinfo + a directory called getPackage which contains the rpm-packages).  The comps-file contains all the group-infos and updateinfo is needed if you want to use yum just for security updates.
Herefor the yum-plugin “yum-plugin-security” is a good choice.

 

UPDATE:
With the “–download-metadata” parameter in the reposync command the updateinfo.xml-files are also downloaded (as far as they exist for the repo). Normaly the file is downloaded in the following format: <HASH>-updateinfo.xml.gz

To use the updateinfo-file in your synchronized repo the file has to be gunziped and renamed to updateinfo.xml – so the hash at the beginning of the filname needs to be striped away. Otherwise it is likely that the updates are not recognized correctly! So convert your downloaded updateinfo-metadata file to updateinfo.xml and run use modify repo to update your repository with the security update informations from the updateinfo.xml.

modifyrepo updateinfo.xml repodata
update the metadata of the local repo