LINUX MAGAZINESLINUX MAGAZINES: Open Source News, Articles and Reviews

When it comes to security, versatility and stability, there is no better solution in information technology than open source. From operating systems to Web development to just about any common application, the open-source revolution finally has taken hold.

Businesses have started to truly understand the benefits of opting for open source, not only to save money, but also for the peace of mind it brings to their IT environment.

The term “open source” has a variety of meanings in the IT world. It is used to describe initiatives and collaborations ranging from software projects to enterprise environments with source code that is accessible to anyone. It stands as perhaps the ultimate example of the process of continuous improvement by encouraging everyone to make it better – and share how they did it.

Many open-source-based solutions like RedHat, Ubuntu and Suse are becoming down-right mainstream, drawing offers for proprietary partnerships from hardware giants like Dell, HP and IBM. So far, each has maintained its autonomy and reiterated its commitment to furthering “the movement” rather than its bottom line.

The issue of support no longer keeps businesses from buying in to open-source technology either. Most are fully supported, either through packages by their distributors, as in the case of RedHat and Suse, or via the well-rounded Internet network.

Open-source now is possible – and pragmatic – for every new Web development project. By using LAMP – that’s Linux, Apache, MySQL and PHP – an open-source solution can be created that is versatile and secure.

Author: Aaron Wittersheim
Article Source: EzineArticles.com
Provided by: Latest trends in mobile phone

Migrating mpio SAN Storage to a Different Array for Linux

When changing SAN arrays, the data needs to migrated from the old array to the new array. After new drives are assigned to the linux server, follow these steps for migrating the data. You will need to get a copy of the inq command for Linux from EMC.

After the new disks from the new array have been added, make sure they are available. Make a note of the serial number (SID) in the right hand column.

(linuxserver)# /nfs/mts/bin/inq.linux -nodots -sidInquiry utility, Version V7.3-883 (Rev 1.0) (SIL Version V6.5.1.0 (Edit Level 883)Copyright (C) by EMC Corporation, all rights reserved.For help type inq -h.

———————————————————————————–DEVICE :VEND ROD :REV :SER NUM :CAP(kb) :SYMM ID———————————————————————————–/dev/sda :EMC :SYMMETRIX :5773 :20010b0008 : 35354880 :000190300520/dev/sdb :EMC :SYMMETRIX :5773 :20010b2008 : 35354880 :000190300520/dev/sdc :EMC :SYMMETRIX :5671 :66001ab000 : 35354880 :000187721466/dev/sdd :EMC :SYMMETRIX :5671 :66001af000 : 35354880 :000187721466/dev/sde :EMC :SYMMETRIX :5773 :20010b0008 : 35354880 :000190300520/dev/sdf :EMC :SYMMETRIX :5773 :20010b2008 : 35354880 :000190300520/dev/sdg :EMC :SYMMETRIX :5671 :66001ab000 : 35354880 :000187721466/dev/sdh :EMC :SYMMETRIX :5671 :66001af000 : 35354880 :000187721466/dev/dm-0 :EMC :SYMMETRIX :5773 :20010b0008 : 35354880 :000190300520/dev/dm-1 :EMC :SYMMETRIX :5773 :20010b2008 : 35354880 :000190300520/dev/dm-2 :EMC :SYMMETRIX :5671 :66001ab000 : 35354880 :000187721466/dev/dm-3 :EMC :SYMMETRIX :5671 :66001af000 : 35354880 :000187721466

After you make sure the drives are available, you need to determine which mpio devices go with which drives.

See what devices are currently active:

(linuxserver)# pvsPV VG Fmt Attr PSize PFree/dev/dm-0 uservg lvm2 a- 33.71G 22.71GRead the the new multipath devices, and see which ones go with the active PV.(linuxserver)# multipath –v2(linuxserver)# multipath -llmpath2 (36006048000018772146653594d314142) dm-2 EMC,SYMMETRIX[ round-robin 0 [prio=2][active]_ 0:0:1:9 sdc 8:32 [active][ready]_ 1:0:1:9 sdg 8:96 [active][ready]mpath1 (360060480000190300520533031304232) dm-1 EMC,SYMMETRIX[ round-robin 0 [prio=2][active]_ 0:0:0:6 sdb 8:16 [active][ready]_ 1:0:0:6 sdf 8:80 [active][ready]mpath0 (360060480000190300520533031304230) dm-0 EMC,SYMMETRIX[ round-robin 0 [prio=2][active]_ 0:0:0:5 sda 8:0 [active][ready]_ 1:0:0:5 sde 8:64 [active][ready]mpath3 (36006048000018772146653594d314146) dm-3 EMC,SYMMETRIX[ round-robin 0 [prio=2][active]_ 0:0:1:10 sdd 8:48 [active][ready]_ 1:0:1:10 sdh 8:112 [active][ready]

From this output, you can determine that /dev/dm-0 corresponds to multipath device mpath0

Now that you know which multipath device is currently active, you need to create a new PV for the inactive multipath device (on new array), which would be mpath2 in this case.

(linuxserver)# pvcreate /dev/mapper/mpath2Physical volume “/dev/mapper/mpath2″ successfully created(linuxserver)#

After you have created the multipath device, it needs to be added to the volume group (uservg).

(linuxserver)# vgextend uservg /dev/mapper/mpath2Volume group “uservg” successfully extended(linuxserver)#

Check and make sure that the multipath device was added correctly to the volume group (uservg).

(linuxserver)# pvsPV VG Fmt Attr PSize PFree/dev/dm-0 uservg lvm2 a- 33.69G 28.69G/dev/dm-2 uservg lvm2 a- 33.69G 33.69G(linuxserver)#

If everything looks good, move the old multipath device (mpath0) to the new multipath device (mpath2) with the pvmove command.

(linuxserver)# pvmove /dev/mapper/mpath0 /dev/mapper/mpath2/dev/mapper/mpath0: Moved: 10.0%/dev/mapper/mpath0: Moved: 20.0%/dev/mapper/mpath0: Moved: 29.4%/dev/mapper/mpath0: Moved: 39.4%/dev/mapper/mpath0: Moved: 49.4%/dev/mapper/mpath0: Moved: 59.4%/dev/mapper/mpath0: Moved: 70.0%/dev/mapper/mpath0: Moved: 80.0%/dev/mapper/mpath0: Moved: 90.0%/dev/mapper/mpath0: Moved: 100.0%(linuxserver)#

After the move is complete, and you verify the data is good, remove the old multipath device from the volume group (uservg).

(linuxserver)# pvsPV VG Fmt Attr PSize PFree/dev/dm-0 uservg lvm2 a- 33.69G 33.69G/dev/dm-2 uservg lvm2 a- 33.69G 28.69G(linuxserver)# vgreduce uservg /dev/mapper/mpath0Removed “/dev/dm-0″ from volume group “uservg”(linuxserver)#

After the device is removed from the volume group, it can be removed from the system.

(linuxserver)# pvremove /dev/mapper/mpath0Labels on physical volume “/dev/mapper/mpath0″ successfully wiped(linuxserver)# pvsPV VG Fmt Attr PSize PFree/dev/dm-2 uservg lvm2 a- 33.69G 28.69G(linuxserver)#

After the multipath device is removed, the old devices in the /dev tree can deleted, so that no errors are generated when the storage is removed. To remove the devices, you need to get a list of the /dev/sd* devices on the old array, with the inq command.

/nfs/mts/bin/linq.linux –nodots –sid_wwn

(linuxserver)# /nfs/mts/bin/inq.linux -nodots -sid_wwn 000190300520Inquiry utility, Version V7.3-883 (Rev 1.0) (SIL Version V6.5.1.0 (Edit Level 883)Copyright (C) by EMC Corporation, all rights reserved.For help type inq -h.

——————————————————————–Symmetrix DeviceSymm Serial # Device # WWN——————————————————————–/dev/sda 000190300520 010B0 60060480000190300520533031304230/dev/sdb 000190300520 010B2 60060480000190300520533031304232/dev/sde 000190300520 010B0 60060480000190300520533031304230/dev/sdf 000190300520 010B2 60060480000190300520533031304232/dev/dm-0 000190300520 010B0 60060480000190300520533031304230/dev/dm-1 000190300520 010B2 60060480000190300520533031304232

To remove the devices just add a “1″ to the /sys/block//device/delete file. Only do this for the /dev/sd* devices, and not the /dev/dm-* devices.

(linuxserver)# ls -l /dev/sd*brw-r—– 1 root disk 8, 0 Mar 9 09:59 /dev/sdabrw-r—– 1 root disk 8, 16 Mar 9 09:59 /dev/sdbbrw-r—– 1 root disk 8, 32 Mar 9 10:09 /dev/sdcbrw-r—– 1 root disk 8, 48 Mar 9 10:09 /dev/sddbrw-r—– 1 root disk 8, 64 Mar 9 09:59 /dev/sdebrw-r—– 1 root disk 8, 80 Mar 9 09:59 /dev/sdfbrw-r—– 1 root disk 8, 96 Mar 9 10:09 /dev/sdgbrw-r—– 1 root disk 8, 112 Mar 9 10:09 /dev/sdh

(linuxserver)# echo 1 > /sys/block/sda/device/delete(linuxserver)# echo 1 > /sys/block/sdb/device/delete(linuxserver)# echo 1 > /sys/block/sde/device/delete(linuxserver)# echo 1 > /sys/block/sdf/device/delete

(linuxserver)# ls -l /dev/sd*brw-r—– 1 root disk 8, 32 Mar 9 10:09 /dev/sdcbrw-r—– 1 root disk 8, 48 Mar 9 10:09 /dev/sddbrw-r—– 1 root disk 8, 96 Mar 9 10:09 /dev/sdgbrw-r—– 1 root disk 8, 112 Mar 9 10:09 /dev/sdh

The /dev tree is removed, and you should only see the new multipath devices now.

(linuxserver)# multipath -llmpath2 (36006048000018772146653594d314142) dm-2 EMC,SYMMETRIX[ round-robin 0 [prio=2][active]_ 0:0:1:9 sdc 8:32 [active][ready]_ 1:0:1:9 sdg 8:96 [active][ready]mpath3 (36006048000018772146653594d314146) dm-3 EMC,SYMMETRIX[ round-robin 0 [prio=2][active]_ 0:0:1:10 sdd 8:48 [active][ready]_ 1:0:1:10 sdh 8:112 [active][ready](linuxserver)#

Remove the old storage from the server, and check the /var/log/messages file for any errors. Then you can reboot the server, and make sure everything comes up okay.

To re-add the drives, the following command can be used to rescan the SCSI bus, and re-register any devices.

echo “1″ > /sys/class/fc_host/host#/issue_lip (run on each host#)

(linuxserver)# ls /dev/sd*/dev/sdc /dev/sdd /dev/sdg /dev/sdh(linuxserver)# echo “1″ > /sys/class/fc_host/host0/issue_lip(linuxserver)# echo “1″ > /sys/class/fc_host/host1/issue_lip(linuxserver)# ls /dev/sd*/dev/sda /dev/sdb /dev/sdc /dev/sdd/dev/sde /dev/sdf /dev/sdg /dev/sdh(linuxserver)#

As a business consultant, web designer and photographer my technical know-how around doing system administration on my Microsoft desktop is limited and sometimes I do require the assistant of my computer engineering son to get it right. In a Microsoft Environment, keeping updated with respect to potential security breaches and patches is a constant vigil. The rigor of keeping current with OS updates, Norton updates and Spyware updates is time consuming. Valuable business hours each week are spend and lost on this task of self-administration dictated by the Microsoft Operating Environment.

So with the purchase of an IBM T40 (a tough notebook), increasing system administration time was not an option. This alone forced an serious consideration of Linux as an alternative operating environment. That was five years ago. Now an established Linux user, I can clearly profess the capabilities and benefits of Linux for small and large businesses, especially, when it comes to notebook deployment.What Linux variant is best for small business and notebook deployment in your company?

As a small and medium business development manager with Sun Microsystems, exposure to Linux and the debate around its viability was a daily event. Questioning and challenging the virtues of Open Source (FREE) Linux versus Licensed Linux versions like Red Hat and Novell SuSE continues to this day . After years of personal use of Open Source (Free) Linux, I can never go back to running the Microsoft Operating Environment on my notebook. And once you can get Linux versions of Quick books, Quick Tax and Picasa (now available on Linux), there is no reason to stay in that perpetual administrative nightmare world of Microsoft.

Having successfully deployed two Open Source Linux variants on my IBM T40 notebook over the last 5 years, a compelling comparison can be made between Fedora and Ubuntu. Fedora, the Open Source version of Red Hat, required the installation expertise of some Linux gurus from Belleville Ontario. It worked fine, but required some Linux ninja system administration every 6-9 months. Administration items applied during these visits included upgrades to Open Office (the open source version of Star Office), Linux OS fixes and new peripheral drivers. This, again, turned out to be a drain on my scarce time for doing real business.

Now the Linux called Ubuntu is installed on my notebook. Ubuntu by Canonical is a full Open Source Linux based on Debian Linux. Ubuntu is now available on Dell systems and Federal Governments are adding this Linux operating environment to their list of standard available OS’s for all desktop and notebook computers.

Right out of the gate, Ubuntu was simple to install. You could even bring down a trial copy to experience exactly how it would behave on your notebook before downloading and committing the Ubuntu OS environment to your machine. But the best part is that Ubuntu continuously keeps on top of OS and all related application software updates. Ubuntu has an Update Manager that magically appears in desktop tool bar. And with a simple click (and password) you are kept current on the latest versions of Ubuntu patches, any Linux application software you have installed from Canonical and Open Office upgrades.

With Linux rebooting your machine after an update is nearly non-existent.

Oh, as an added treat with Ubuntu, Ubuntu boots up on your machine in less than a minute. I still go get a coffee when my Microsoft desktop is booting up. An additional benefit of Ubuntu: there is no requirement for installing ant-virus and anti-spyware software. Ubuntu inherently repels these vial scourges of the internet.

With Ubuntu your system administration life will become simple and painless. You can spend more quality business hours selling and marketing.Want to cut hidden costs in your organization that manifest themselves as Microsoft self-administration by your end users?

Ubuntu is a must for you or your IT folks to consider. Seriously consider, test and deploy.