Friday, August 29, 2008

Backup

Like insurance, computer backups are the type of item that feel like they 'cost' more than they ever return. This feeling is quickly reversed the instant a backup is put to use, but depending on the shop, backups typically happen a lot more often than restores. There isn't any question backups are a necessity, but the real question are: How and Why.

The "Why" question really refers to selecting the best "How" for a shops situation: Why is this my solution. It involves details like: how much data must be backed up, how often must it be backed up, how fast must it be backed up, how fast must it be available for restoration, where must the backup be stored, etc.

I've ran across a few different "How's" in my career. Some of these involved FC attached libraries, autoloaders, single drives. These are all 'local' backups, where the data was copied to some type of local device and managed locally. There is something to be said for today's modern tape technology - it is soo much better than from 5-7 year ago. Speeds are great, capacities are way up, reliability is significantly better. But - tape is labor intensive, having to be handled, moved offsite, back onsite, sensitive to temperature, etc. Good quality tape drives(LTO and up), either stand alone or inside an autoloader/library are costly for smaller businesses. And when a tape drive decides to start acting up, it is your own worst enemy - writing bad data, eating tapes, failing backups.

In recent years an additional local backup has come into popular use - disk. The plummeting cost of disk drives and sky rocketing capacities have made disk drives a very attractive backup option. There are 3 approaches used with disk backup: 1) Disk replaces tapes. Here backups are written to removable drives and then moved offsite / rotated just like a tape would be. 2) Backups are written to disk first, then tape - known as D-D-T(Disk to Disk to Tape). Here the disk acts as an intermediary(with many benefits). 3) Mirrored remote SAN. This is big business stuff mostly using expensive equipment and network connections to actively mirror live data. It's also more of a disaster recovery / failover solution as it does not preserve historical versions.

Going back to #2 above and the "Many Benefits" part. By putting the disk between the data source and the tape drive several good things happen. First off many backup streams can be written to a disk simultaneously, minimizing jobs having to wait for a tape drive to be free. Secondly because these disks are usually in the backup server or 'near' it, when the data is written to tape from them it can be done much more quickly / smoothly, freeing up even more tape drive time. Thirdly, there are now 2 copies of the backup, always a plus. Lastly, if the data is still on the intermediate disk when a restore is requested, the data can be pulled from the disk instantly versus searching for, loading, and seeking through a tape.

There are too numerous to mention local backup software options. The keys to the proper selection mainly involve: The kinds of data being backup up(database, email, normal files, etc), the type of systems being backed up(Windows, Linux, UNIX, etc), and cost. All reputable softwares should support modern media types, be it tape drives/loaders/libraries, VTLs, or disk drives.

Another option exists that can be attractive in certain situations - online backup. Online backups start with an account on a vendor website, an Internet connection, and a small piece of software on the source systems to be backed up. Often times there are options for the backups to run continuously - capturing all file changes in real-time and transferring them securely online for backup, or scheduled backups that only run at certain times. There are a few immediate cautions with these solutions. 1) Is the Internet connection fast enough to transfer the data efficiently? 2) How is the service charged: per MB transferred/per MB stored/per MB on the source system/etc? 3) What options exist for restoring data, both small files or entire systems? An online backup can be a good match given the right billing structure and a desire for low IT resources.

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Thursday, August 28, 2008

Active Directory Restore Fun

This adventure all began with testing out a remote access application. In my earlier experience testing a previous version of this application, it pulled a local copy of my Active Directory users and groups during initial setup which then had to be pruned down to those who actually needed remote access. After setting up the most recent version, I promptly began pruning the users and groups shown in the application to the appropriate list - then the phone rang.... Needless to say the current version of the application was directly accessing AD, not just for authentication, but to maintain its user list --- that I had been actively pruning.

Needless to say this was not the best situation. No fear - there are backups for this sort of situation. But beyond backups, the restoration of AD is not a two click and it's done operation. This isn't a story about "Oh no the backups junk" or backup schedule philosophies, but I will comment of the merits of using Disk-Disk-Tape backups quickly - backup & restores are quick. Back to AD. My AD landscape is fairly simple: single physical site, 3 DC's, relatively small database.

I don't carry any MCxx certifications and thankfully the opportunity to perform this type of operation is not a common thing. Thankfully between MS Support Knowledgebase articles and documentation in my backup software the AD restore operation was smooth.

I had restored a DC in a VMware test environement before, but it was a single DC configuration which changes things a bit. Aside from not realizing up front how the remote access application integrated with AD the following lessons can be taken away:
1) If at all possible have a test environment similar to production - and try these things out.
2) Have knowledge of proceedures or how to find it - quickly
3) Take a deep breath when these things happen - think quickly, act thoughtfully
4) The addage of one-application to one-server is priceless in restore situations
5) Having multiple DC's even in a small environment helps keep things moving along.

[Update on Backup / Restore resources]
AD Restore on 2K - Works for 2k3 (MS Support KB)
Good notes on using NTBackup on DCs for Backup / Restore (MS Support KB)
I use Symantec Backup Exec in my environment, but NTBackup is good for just a few systems.

Thanks for the comment Matt & good luck jumping into MS infrastructure (I'm a *nix guy by trade too).

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Wednesday, August 27, 2008

Virtualization in Small Companies

The news and media have been chock full the term Virtualization for over the past year and very heavily so since 2008. There are various offerings from several prominent vendors and a new option seems to pop up every few weeks. From a small company point of view these offerings appear catered to larger business. After all many companies out there don't have hundreds, let alone tens of servers - and what's a 'SAN' anyway.

I'm not sale rep / associated with a sales rep from any of the virtualization solution companies. I will however say there are very compelling reasons to use the technology, even in the smallest of environments. Akin to this - many of the 'beginner' virtualization solutions are free to no cost and as such can not be used as an excuse to avoid the technology. In fact, the use of virtualization in companies with only a few systems can be very compelling for some of the following reasons.

1) Hardware Independance. When you only have a few servers and suffer an equipment failure, recovering a hardware dependant system is a nightmare and a huge prioirity. VM's are run against a virtual BIOS/hardware that is more or less identical between host virtual server systems. This means a virtualized system can be restored to another host with little to zero hardware / driver issues and be off and running fast - priceless!

2) Hardware Cost Savings. Starting with 2 physcial systems consolidated to one, hardware savings are acheived. For the sake of having a backup host this isn't the best idea but the savings concept is key. Virtualizing only a handful of systems eases the selection of equipment. A modest system by today's standards can run a handful of virtual servers without worrying about having a high performance SAN or similar storage / network environment.

3) Return on equipment investment. Every business purchase is an investment, and getting the most value from each dollar spent is a big factor in buying decisions. Consider 4 servers, each costing 2 to 3 thousand dollars each. This situation presents a total investment of 8 to 12 thousand dollars and lots of computational power generally sitting 85% idle, with 4 sources of heat, space and power consumption. Virtualize those 4 systems to one 4 to 6 thousand dollar server saving thousands up front with one source of heat, power use, and noise. Or conservatively to two 4 thousand dollar servers still spending the same or less on equipment but halving the noise, power use, and heat dissipation and still reaping all the other benefites mention here.

4) Testing. Using virtualization opens the doors to smaller shops where it isn't feasable to have equipment dedicated for testing. A modest desktop with enough memory can run a handful of VM's for configuration testing purposes.

5) All the usual suspects: Less equipment space, less electricity, less heat produced, less noise, longer battery backup runtime, etc.

All this being said there are of course drawbacks. Virtualization brings along with it new concepts in system management that must be understood. Administrators must generally have a strong understanding of system resources to maintain an effective virtual environment: system memory, disk IO, networking. For smaller shops, putting many VM's on one host creates a "Many eggs in one basket" situation. Backups - there are additional backup options avaialbe to VM's that need to be understood. Certain applications do run better on dedicated physical systems versus the virtualization environment a small shop could support.

All in all virtualization is great. Even utilizing the free solutions available, great efficiences can be acheived compared to 'old school' one system to one physcial computer. You don't have to be a 'big' shop or invest thousands to reap the many benefits of virtualization!

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Tuesday, August 26, 2008

Hello World

I've come to the realization over the past several months I've enjoyed reading a handful of other tech related blogs some more technical, some more business oriented and decided I would try my hand at one. I've found good genuine technical advice, invaluable real world experiences, and just plain enjoyable reading out there and feel I should relay some back.

It's also becoming a staple for most professional careers to document one's experiences. In this world full of (often too) much public information, the importance of personal experience and sound information is invaluable. I'm certainly not the definitive source for some if any topics, but I have to be for both my family and the real world issues I deal with daily.

A short list of the things I deal with each day(Search engine food mostly): Windows Servers, Active Directory, Wireless Networking, SQL Server, MS Exchange, Citrix, Office Applications, LAN, WAN, VPN, Linux, Security, Backups, iSCSI, Phone systems, Remote Access, Capacity Planning, Budgeting, Business Policy, Office Politics, Virtualization, A/V Systems, Firewalls, SAP, etc. All the fun things in today's modern businesses.

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