Email conversation with one of the Blog reader who is interested in learning more Storage but passionate to work as a programmer

Hi Roger,

Thanks a ton for writing a blog on Storage career opportunities and thanks for sending those Storage tutorial pdf materials.
Though i am working for a storage company for about an year,i am still perplexed with
storage complexities,market requirement, storage technologies
(DAS,NAS,SAN,SCSI,iSCSI to name a few), and i was unsure of my career roadmap as well,but after finding so many kool stuff on your blog,i'm excited with joy and aspiration.

~Aron
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Hi Aron

thanks for your email nice to know your feedback .
So do write more about ur tech experience & how is your work on storage.
what are the challenges& responsibilities you handle.

Rgds
Roger
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Hi Roger,

I'm working as a Quality Assurance-engineer( Some call the same designation as Product Verification Engineer or Product Testing Enginner) and my task involves certifying Backup & Volume Manager(which is basically an management interface which ultimately talks to SAS Storage devices & iSCSI drivers)and file system features, using already developed testsuites & testscripts.
(which mean not much is there for me to develop,beside fixing testsetup related bugs)
,beside this i do a little bit of troubleshooting and automation using perl,shell scripts.
Due to lack of bandwidth here (in my organisation) and company policies,i am not able
to sharpen my skills in systems programming and kernel level programming(which is my passion),i'm looking for opportunities where my primary work is doing what i love most(programming).hence i'm looking for such opportunities in storage domain.

Impatiently waiting to hear from you,
~Aron
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Hi Aron

I am sorry for delayed reply. I'd have loved to reply earlier but due to some hectic schedule I got a chance to do that only now. So i understand your mind to some extent. May be few lines from my thoughts may be of some help to You

Since you are saying you are much interested in programming you can gain more expertise in that by participating in some open source storage projects : where u get lot of freedom but the only problem is no pay :)

So if you are aiming for getting into a job where they pay well & allow you to code then I would say gain more in depth knowledge on as much storage fundamentals as u can - this way you can clear lots of Bigger storage company interviews which pay well & they definitely need someone to come for programming role for their storage business solutions.

So improve your programming skills as well as gain very good grip on major storage concepts like Fibre Channel,SAN,iSCSI,FS Switches,Storage arrays etc & then I can send you some documents to help you get going on these.

write to me what is your expected pay package if u wanna change & whats the present pay.I will see if there are any chances for something to be done to help you.

I do not want to promise much but if you work hard & constantly email me your progress I can definitely guide you to some extent - But ultimately I like to see long emails detailing what you are studying & how you are learning things & gaining more expertise :

I may publish some of our conversation on the blog (Removing all personal details & other confidential details) so I want people who share lot of tech stuff from their side & I will help them as much as I can

Rgds
Roger

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Hi Roger,

Thanks a lot for sharing words of wisdom with me.
Those pdfs are really kool, thanks again.

I work on SGI ,Solaris ,Linux platform and work closely with Volume managers.
Recently i got some Vmware virtualization exposure and these days i'm trying to explore more about it.
Thank god we have vmtn.com ,which is an awesome site with zillions of information on vmware virtualization
and beyond. I've learned a lot from forums at this site.This is a must visit site and i must say that if anyone is serious to learn Vmware ESX Server or Virtual Centre and art of troubleshooting then join forums here.

Also whenever i get time, i practice programing.
I'm almost done with "Advanced programming in UNIX" by Richard Stevans,which
gave me good insight of UNIX APIs.
Beside this i'm reading some books on OS and Linux kernel,which are:
a) "Modern Operating Systems" by Andrew S. Tanenbaum
b) "Linux Kernel Development" by Robert Love.
c) "Linux Device Drivers" -3rd Edition

Roger, Thanks for taking out your precious time and writing to me.I'll certainly keep you updated with my latest learnings and experience in storage domain.

Regards
Aron

Veritas Volume Manager Tutorial for Storage Professionals

Many storage pros from other job profile's might not have complete idea about Veritas volume manager. To make the readers of this blog aware of this very popular Storage software this blog is a brief tutorial about Veritas Volume Manager & its features.

Veritas Volume Manager, VVM or VxVM is a proprietary logical volume manager from Veritas (now part of Symantec). It is available for Windows, AIX, Solaris, Linux, and HP-UX. A modified version is bundled with HP-UX as its built-in volume manager. It offers volume management,Multipath I/O functionalities,scalability, availability, and recoverability features.

Answers to Interview Questions on Veritas Volume Manager

EMAIL roger.smithson@gmail.com & GET FREE SAN TUTORIAL GUIDE.(PDF:124 PAGES)

Thanks to Ashish Pathak for all the questions and also answers to Interview questions on Veritas Volume Manager.

# Name the mandatory disk group in VxVM 3.5 ? How will you configure VxVM in 3.5 ?
ANS: rootdg is the mandatory disk group in VxVM 3.5, vxinstall is the command to configure VxVM, It will create the disk groups, initializes the disks and adds them to the group.

# How will you create private and shared disk group using VxVM ?
ANS: For Private DG:
Command: vxdg init

For Shared DG:
Command: vxdg -s init < disk1 disk2 disk3 >

# Which are the different layouts for volumes in VxVM ?
ANS: mirror, stripe, concat (default one), raid5, stripe-mirror, mirror-stripe.

# What is the basic difference between private disk group and shared disk group ?
ANS: Private DG: The DG which is only visible for the host on which you have created it, if the host is a part of cluster, the private DG will not be visible to the other cluster nodes.
Shared DG: The DG which is sharable and visible to the other cluster nodes.

# How will you add new disk to the existing disk group ?
ANS: Run vxdiskadm command, which will open menu driven program to do various disk operations, select add disks option or you can use another command vxdiskadd.

# How will you grow/shrink the volume/file system ? What is the meaning of growby and growto options ? What is the meaning on shrinkto and shrinkby options ?
ANS: vxassist command is used to do all volume administration, following is the description and syntax.

Growby option: This is will grow your file system by adding new size to the existing file system.

Growto option: This will grow your file system as per the new size. This WILL NOT ADD new size to the existing one.

Shrinkby option: This will shrink your file system by reducing new size from existing file system.

Shrinkto option: This will shrink your file system as per the new size. This WILL NOT REDUCE the file system by reducing new size.

Command:
vxassist -g [growto, growby, shrinkto, shrinkby] length

# How will you setup and unsetup disks explicitly using VxVM ?
ANS: You can use /etc/vx/bin/vxdiskunsetup to unsetup the disk, and /etc/vx/vxdisksetup to setup the disk.

# How will you list the disks, which are in different disk groups ?
ANS: vxdisk list is the command will list the disks from the DG which is currently imported, you can check the same using vxprint command too. vxdisk -o alldgs list command list all the disks which are in different dg's.

# What is the private region in VxVM ?
ANS: Private region stores the structured VxVM information, it also stores the disk ID and disk geometry. In short words it has metadata of the disk.

# If, vxdisk list command gives you disks status as "error", what steps you will follow to make the respective disks online ?
ANS: If you faced this issue because of fabric disconnection then simply do vxdisk scandisks, otherwise unsetup the disk using using /etc/vx/bin/vxdiskunsetup and setup the disks again using /etc/vx/bin/vxdisksetup, this will definitely help! [ /etc/vx/bin/vxdiskunsetup will remove the private region from the disk and destroys data, backup the data before using this option]

I am greatly thankful to Ashish Pathak ashish.rp AT gmail.com for emailing & contributing this real interview questions on Veritas Volume Manager