SC101-nbd gfs2 HOWTO Darrin KhanSC101-nbd gfs2 HOWTOby Darrin KhanCopyright © 2007 Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License (http://www.gnu.org/copyleft/fdl.html) Version 1.1; with no Invariant Sections, with no Front-Cover Texts, and no Back-Cover texts. A copy of the license is included in the GNU Free Documentation License appendix.Revision HistoryRevision 0.12007-08-27Initial revision, released for comment and feedback.Revision 0.22007-09-03Added _netdev information for alternate file systems.Table of Contents1. Introduction.Legal Stuff.Updates.2. Pre-requisites.sc101-nbd.Init Scripts.gfs2-utils.3. Configuration.Partitioning.Create Partition.Attach The Partition.Create the gfs2 filesystem.Update fstab.Create Mount Point.Edit /etc/fstab.Final Steps.Test gfs2 init script.Alternative to gfs2 init script.Final Config.4. Conclusion.A. GNU Free Documentation License.List of Examples2-1. ut listall Output.3-1. sc101-nbd configuration file.3-2. fstab entry.3-3. /etc/fstab file.Chapter 1. IntroductionChapter 1. IntroductionChapter 1. IntroductionThis HOWTO describes the steps that I took to implement the user space sc101-nbd software for linux. The sc101-nbd software allows a linux system to communicate with the Netgear Storage Central 101. More information can be found on the sc101-nbd projects website http://code.google.com/p/sc101-nbd/. The main reason for me to get this going was to serve as a storage location for my MythTV setup.In this HOWTO I will base the install on a Fedora Core 6 installation. If anyone knows of other notesor information that could be added for Distribution specific changes please shoot me an email.Legal StuffPermission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License (http://www.gnu.org/copyleft/fdl.html) Version 1.1; with no Invariant Sections, with no Front-Cover Texts, and no Back-Cover texts. A copy of the license is included in the GNU Free Documentation License appendix.UpdatesThis is an evolving document, as such information and additions are welcome. The authoritative and most up to date version of this document is available from http://www.dknss.com/data/sc101-nbd-init/. Please send your contributions Darrin Khan < darrink@gmail.com (mailto://darrink@gmail.com) >.Chapter 2. Pre-requisitesChapter 2. Pre-requisitesChapter 2. Pre-requisitessc101-nbdThe first thing to do is download and install the latest sc101-nbd package. This can be downloaded from http://code.google.com/p/sc101-nbd/. As at writing this was sc101-nbd-0.03. As I installed on FC6, I grabbed the rpm package. Once downloaded this can be installed with a command like:rpm -ihv sc101-nbd-0.03.i386.rpmThis will install all the files needed to access the sc101. To test that you are able to see the sc101 issue the command:ut listallThis should return a listing like the following:Example 2-1. ut listall Output=============================================================================== VERSION : 4.22.13 ROOT IP ADDR : 10.x.x.75 TOTAL(MB): 152623 # PARTITIONS : 6 FREE (MB): 24623 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - PARTITION LABEL IP ADDR SIZE (MB) FE9F5820-B0A8-11DA-8959-005056C00008.m1 photos 10.x.x.80 51200 912E2720-B0EA-11DA-895A-005056C00008.m1 games 10.x.x.91 5120 4DF40FA0-B341-11DA-91ED-000D88F131F9.m1 backups 10.x.x.92 20480 2D2283A0-E121-11DB-89C2-000A3A559ACB.m1 d2 10.x.x.99 10240 898FC1D0-5178-11DC-89ED-005056C00008.m1 linux0 10.x.x.79 10240 71FD61D0-51D9-11DC-89ED-005056C00008 myth1 10.x.x.78 30720 =============================================================================== VERSION : 4.22.13 ROOT IP ADDR : 10.x.x.96 TOTAL(MB): 152623 # PARTITIONS : 6 FREE (MB): 24623 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - PARTITION LABEL IP ADDR SIZE (MB) FE9F5820-B0A8-11DA-8959-005056C00008 photos 10.x.x.95 51200 912E2720-B0EA-11DA-895A-005056C00008 games 10.x.x.93 5120 4DF40FA0-B341-11DA-91ED-000D88F131F9 backups 10.x.x.73 20480 2D2283A0-E121-11DB-89C2-000A3A559ACB d2 10.x.x.98 10240 898FC1D0-5178-11DC-89ED-005056C00008 linux0 10.x.x.81 10240 A7110910-51D9-11DC-89ED-005056C00008 myth0 10.x.x.77 30720 =============================================================================== Once you have gotten this far you should be able to communicate with the sc101. If you have problems getting to the sc101, make sure you can ping the sc101. You can find the IP address of the device via the Win32 GUI that ships with the sc101.Init ScriptsThe next thing to do is download and install the init scripts for managing the sc101-nbd. These can be downloaded from http://www.dknss.com/data/sc101-nbd-init/. These are available in both rpm and tar formats. Others will be available in the future.Once again as I am running FC6, I grabbed the rpm package. This is then installed via:rpm -ihv sc101-nbd-init-0.01.i386.rpmThis will give you 2 files, the init script and the config file. The config file is in /etc/sysconfig/sc101-nbd and the init script should be in /etc/init.d.gfs2-utilsWith the setup that I have, I chose to use the gfs2 filesystem. The two primary reasons for this is:1) The gfs file system is designed for clustered filesystems. and2) It provides a nice interface to bring the file system up after the network and block devices are available.This can be installed using yum. The following command should do the trick:yum install gfs2-utilsOnce installed you can move on to configuring the partition(s).Chapter 3. ConfigurationChapter 3. ConfigurationChapter 3. ConfigurationPartitioningBefore we can edit the config file for the sc101-nbd, we need to configure a partition specifically for the linux box(s) to use. This is a requirement due to linux not having direct access to the filesystem type that is used on the sc101s.Create PartitionFirst go to the sc101 GUI, and create a partition for the linux servers to use. Make sure you note down the label you gave the partition.Attach The PartitionTo attach the partition, we need to add the partition label to the /etc/sysconfig/sc101-nbd configuration file. Using your favourite editor add a line similar to the following to the default configuration file. By default the configuration has no attachments enabled.Example 3-1. sc101-nbd configuration file# # SC101 mount points and IDs # # SC101 mount point name,local nbd device linux0,/dev/nbd0 The line listed above will attach the partition linux0 to the device /dev/nbd0. This device must be unique for all partitions. So for linux2 you could attach it to /dev/nbd1.At this point you should be able to activate the attachment by issuing a service sc101-nbd start. This should attach the partition to the device /dev/nbd0.Create the gfs2 filesystemTo create a gfs file system on the newly created and attached partition, execute the following command.mkfs.gfs2 /dev/nbd0This may take a minute or 2 to complete depending on the size of the partition and the speed of your network. In its default configuration, gfs will be in single host mode. If you will be running more than one host and attaching the same partition to multiple hosts, and have the fencing hardware for it, use something like CentOS in a cluster configuration. That type of setup is for the hardcore linux enthusiast and is not covered in this HOWTO.At this stage you can do a test mount and make sure that you are able to read and write to the filesystem. You can use a command similar to the following to do this.mount /dev/nbd0 /mntThis will mount the new filesystem at /mnt. You should be able to copy files to and from this point, make directories etc. If all is going well, you can umnount the filesystem with:umount /mntUpdate fstabCreate Mount PointWe now need to work out where to mount the filesystem in the future. On my systems I tend to use /data for my network filesystems. In this case I would use /data/linux0. This can be created with:mkdir -p /data/linux0This will create the /data directory and the /data/linux0 directory.Edit /etc/fstabWarningIf you are unfamiliar with what this file does and its place in the scheme of things, make a backup of it now. If this file is corrupted or damaged in anyway, you may end up with a system that is unable to boot. If you are unsure, _don't_ edit this file, find someone who can help you.Now we have attached a partition, created a filesystem on the patition and created a mount point, we can add it to the /etc/fstab file. This file contains lists of partitions and information for mounting the filesystems at bootup (and other mount processes). Open the /etc/fstab file in your favourite editor and add a line similar to:Example 3-2. fstab entry/dev/nbd0 /data/linux0 gfs2 defaults 0 0This should give an fstab file similar to:Example 3-3. /etc/fstab file/dev/VolGroup00/LogVol00 / ext3 defaults 1 1 LABEL=/boot /boot ext3 defaults 1 2 devpts /dev/pts devpts gid=5,mode=620 0 0 tmpfs /dev/shm tmpfs defaults 0 0 proc /proc proc defaults 0 0 sysfs /sys sysfs defaults 0 0 /dev/VolGroup00/LogVol01 swap swap defaults 0 0 /dev/nbd0 /data/linux0 gfs2 defaults 0 0 There are various tweaks that can be done to speed up the file system access, like setting the noatime paramater. This is a discussion for another paper, and if you Google for filesystem optimization, I am sure you will find lots of details on it. You can now test the fstab entry by manually mounting the filesystem with a command similar to the following:mount /data/linux0You should now be able to access the data that you created earlier and read/write to /data/linux0. Once you have finished testing this, unmount the filesystem again with:umount /data/linux0Final StepsTest gfs2 init scriptAt this stage you should be able to start and stop the sc101-nbd and gfs2 filesystem init scripts. This can be done the following commands:Note: The start and stop order is important. If you stop the sc101-nbd before you unmount the gfs2 filesystem, you will create a dead lock and may need to reboot the system. Always start the sc101-nbd before the gfs2 script and stop the gfs2 before stoping the sc101-nbd.service sc101-nbd startservice gfs2 startAt this stage you should have the filesystem mounted again on /data/linux0 and be able to read and write to it. To stop them use the following commands:service gfs2 stopservice sc101-nbd stopThe filesystem should now be unmounted.Alternative to gfs2 init scriptAn alternative option to using the gfs2 start script is to use the _netdev option in the fstab file. This should make the entry be processed by the /etc/init.d/netfs start script, which fires after all the networking has loaded for network file systems. This should allow you to use any other file system of choice, like ext3, reiserfs, xfs ...*Contributed By: Iain Wade Final ConfigThe only thing left, is to make sure they start and stop when the system boots and shuts down. This can be done with the following commands:chkconfig --add gfs2chkconfig --add sc101-nbdchkconfig gfs2 onchkconfig sc101-nbd onChapter 4. ConclusionChapter 4. ConclusionChapter 4. ConclusionYou now have a partition that will be attached from the sc101 to your linux box and mounted at startup. While this HOWTO only shows one partition being used, there is no reason you can't repeat the above steps for multiple sc101 partitions and or sc101 devices. While I have not tested this in an environment with more than one sc101, it should work, as is, due to the way the init script searches for the partition names.As this is the process that I went through, if anyone has any further details or additions for this HOWTO, please drop me a line to darrink at gmail dot com.Appendix A. GNU Free Documentation LicenseAppendix A. GNU Free Documentation LicenseAppendix A. GNU Free Documentation LicenseCopyright (C) 2000, 2001, 2002 Free Software Foundation, Inc. 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. 0. PREAMBLE The purpose of this License is to make a manual, textbook, or other functional and useful document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. 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