Redundancy and clustering

Have you looked into file replication over multiple NAS servers? I am still reseaching because I am in the process of planning the same. But this is one of the solutions I have seen. A few NAS servers that run Hot Swap RAID arrays.

Benefits and Features of the NAS 200m/160GB
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How Can I...
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Use my NAS server as an interim backup for tape?
Backing up to a tape drive can often extend beyond the window of time available each night, causing you delays ? and since only one server can back up to a tape device at a time, those delays can be considerable. But there is a better way! Use your Iomega NAS server as an interim or near-line solution to save you valuable time. With NAS, multiple servers can write to a dedicated NAS device simultaneously (and many times quicker than writing to tape), so it doesn?t matter if the tape drive takes all night to backup from the NAS server. Plus, this solution adds another point of failure/protection to your network, and restoration of files from a NAS device is extremely easy and efficient.

Technical Information

Microsoft Windows Powered OS
Microsoft Services for Unix
Microsoft Services for Novell
File Services for Macintosh
Native support of Active Directory Services and DFS aggregation
Computer Associates? eTrust? Antivirus 7.0
Iomega NAS 200m/160GB
Intel P4 Celeron Processor, 1.7GHz
256MB RAM
RAID 0, 1
Single 10/100 Ethernet
2 x 80GB Hard Drives, 7200rpm
1U Form Factor
2 USB 2.0 Connections
Service & Support: Limited three year parts and labor, 24x7 telephone support and E-mail with 4 hour response time.

Cluster servers are the only real way to get the 99.9% uptime your asking for, Nas are nice and I personally don't have problems with them except limitations they create. If you can afford NAS units then use real servers and run BSD or Linux on the servers, put your money in mulitple NIC's and Server Hardware with SCSI RAID CONROLLERS, not a IDE raid controller. These systems are inexpensive, then use the DFS since you have MS Win Servers to show the file shares. (Please note: you will have to learn linux to utilize these systems if you do not already use it.) If you use multiple NIC's you can have a dedicated pipe between servers and use replication 24x7 for this and any other data for servers only, then route normal traffice through other NIC in server, also make sure you use switches and not standard hubs. Hubs may be 100Mbit but you must devide the amount of ports into 100 to find the true data rate, switches are inexpensive as well and you will have the redundancy you are looking for.

Linux can function BDC style without problems in the AD setup. If MS systems get hit by virus network stay's up while you take down the AD Server in MS world of AD there is no more PDC/BDC all systems are PDC's again Linux can perform flawless and clustering will out perform the MS systems we already use this set up and save money creating a balance and then the set-up saved us more than once.
Anyone Else?

You have so many options available to you at a cost. The quick cheap and cheerful solution would be to utilise the tools that W3K has built in. Create a DFS share and use DFS to automatically replicate the data from the hub server to the spoke server. You can set this up in a few min, setup a replication schedule and then look at other software solutions if you find that this does not work for you. Good luck.

I have put together our company's plan for DR on our networks and have maintained it for 6 years. My recommendation for your question is to use Cisco's CSS 11500 series cluster switches. You can redirect traffic from 1 location to another almost instantly and have it work automatically. These switches are not cheap, but they work and are reliable. I have a friend who works for a large utility company that uses them for their redundant data centers.

(All professionals will surely know that, but...)

Apart from legal reasons, even with a perfecly working system, redundant to the max, there is no way around tape backups and archives.

Imagine having to restore data accidentally deleted yesterday.

Or - a virus attack that destroyed files.

Not to mention the feds needing old data...

First thing is...ditch the tape. RAID Arrays are way down in price. Depending on your data size, you could also consider iSCSI. Either way, you can purchase TBs for between $5K/TB to $3K depending on array capacity. iSCSI will be more, but it handles the VPN a little cleaner. There are packages available for snapshots and M2M amdn Many to 1 replication. In another response, the switch redirect is nice also.

Hi!

Here we use W2K (W2K3) DFS for file replication and it does a great job and the price is right ( It's free).

We also use W2K advenced server for clustering SQL enterprise DB and SQL log shipping features for database replication and availability.

We also have a LAN Extention between our sites and VPN backup links.

But don't forget that tape(removeable media) backups are not something you (or anyone) can live without, they are mandatory for any real Disaster recovery/ or auditing purposes (court trial, hacking detection offline after the fact).
And DB/Email/files resotration.

Don't forget that replication is synchronious so a big booboo at one end is also a big booboo at the other end !!!!

So My 2 cents are:

Backup often and on different medias, Tivoli
Storage Manager (5.2) is the best backup archive solution on the market once you learn how it works!!

P.S.: I'm on no way related to IBM, Tivilo, etc

Eventhough I sound like a big Microsoft dude, I'm actually a UNIX admin have been for 15 years. As much as I hate to admiit MS is doing a good job with the features of SQL and W2K3.

And as far as Linux goes you can do it all with Linux as long as you want to spend a bit of time configuring it.

Linux is probably more stable than Windows but if your not a UNIX guru, You're probably betrer off with MS software.

Yves

What's a few days when you are considering all the companies DATA? The systems that you talked about are only useful for very small business who doesn't store much data digitally and has hard copies of the files.

I too have see horrendous cases of tape being useless but it has always been down to "Human Error or lack of knowledge" like a case a few years ago now where those in charge thought to save a few $ they would get the Security Guard to run the daily Tape Backups. He of course knew nothing about anything concerning computers and followed the instructions he had been given to the letter. The only problem was the tape drive had failed and only ran for 5 - 10 seconds by which time he had left and gone on his rounds. The next morning the office staff removed the tape and replaced it with that days and took the backup into a secure location. The only problem was that this went on for 6 months and was only discovered when the server failed.

To me the biggest problem with DR is the Human Factor and if you can remove this as much as possible it works better.

SO I would always recommend a dedicated server with a tape autoloader who's only job is to perform backups either daily or incremental that way unless the Human involved forgets to change the tapes over it is as secure as possible.

Personally I've seen far too many HDD fail and even a few days involved in recovering the data is cheep compared to requiring the failed drive/s being sent away to be stripped and have the data recovered which takes a lot longer than a few days and costs a lot more. Not to mention the fact that once this happens you lose control of the data. So if security is a very real issue your only alternative is to have a fully fitted out forensics ability on site and even then a few days would be considered as luxury compared to the time required to recover the data.

Col

The advances in file compression technology coupled with DVD writing and re-writing capabilities make them an ideal tool for replacing the old tape backup devices. If you have a high-powered system management pc with lots of drive capacity, consider setting up a backup strategy using PkWare or Winzip and archive the zip files to DVD or CDR. Copy or zip across the network to your management pc during the lowest usage time frame and zip/archive from there. Best of all, the data will be accessable from almost any workstation for disaster recovery.

1) Frequently, systems that add system complexity for the purpose of providing real-time protection can end up *causing* the protected systems to fail more often due to the added complexity.... and then they're harder to fix.

2) The cost and complexity of doing real-time replication and failover is *much* higher then the cost of doing near-real-time (lets say with an acceptable 30 minute replication lag). Reality check: People will spend an 30-60 minutes going to lunch and another 30-60 minutes doing other non-work activities during the workday. So whenever some zealot tells me that we can't tolerate even 5 minutes of down-time (ever) without causing major damage to the company, I recommend that he see his doctor for a lithium prescription.

3) Any DR strategy that integrates the DR system with the host OS that's being protected is just begging for trouble. It's time to think in terms of backup appliances and replication appliances. Separate the protection function from the devices being protected. I have no doubt that the cost on these will come down rapidly in the next year or so.

A good one to look at now is http://www.unitrends.com/appliancetechnologies.php?id=7

Their website is not particularly well organized or well written, but I've tried a demo system and been very impressed with how bulletproof and easy to use it is.... enough so to make me issue a P.O.

I should mention that I'm currently using Veritas v9 with various add-ons. I liked the older Veritas version a lot better than I like v9. Somehere along the line, Veritas got the peculiar idea that backups were rocket science and that they needed to be the star of the show. Wrong! No more Purchase Orders for you....

NAS Servers are a brilliant way to seperate processing from storage. It's more like connecting a network printer, even if your server fails, data transfer between clients & the NAS will continue, thus ensuring Fault Tolerance. Since NAS has it's own OS (Windows Storage Server 2003, for instance)the ACL's on files & folders are also controlled there.
But NAS is pretty expensive when it comes to implementation!! So give it a thot if you have budget issues!!

Hey guys dr is what it is, the best you can do. (just like with your kids :) ) tapes were used in the days of high costs for data storage and were not always reliable but it was the best you could do within budget. Now we have many options to go with that are not as costly as in the days of yor. We will still use tape but only in the last piece of the chain so to speak. We are going with Intradyn rocket vaults as the backup and co-standby for the servers for fail over and backup at 3 diff. locals, of course the tape will backup the Intradyn but will not be considered the
first choice in restoring when a failure accures. So just do the best you can and get some sleep.

Well, you have to write To-Do tasks. First secure your closest servers making replica of them and joining both to a cluster environment as you are running 2k3 core servers. For your database, if it is Oracle, try RAC. Test everthing, unplugging cables, change resources to other node on a cluster. Then, use the T1 as your desister recovery to a small network consisting of the servers on NJ for example. If you have a router (CISCO CATALIST 6500) you can implement a disaster recovery to this site, or configure a new one to substitute when failures, pointing to your remote site. Remeber there is not 0 Downtime if a tornado comes in your place.

What are you referring to as tape drives?
I'd assume DLT's or 8MM's.
Are you aware that there are tape drives that sustain 20+ MBY/sec transfer rates to their media?
We have found that in large media set environments that a mixture of backup (media) types usually provides a high level of data safety.
A lot depends on the data and the environment.

In terms of internal server redundancy, 0 downtime in reality is not obtainable, however for Windows based servers the Stratus ftServer line of systems are the only option that truely achieves 99.999% uptime.

Stratus systems are also simpler to implement and maintain than Windows clusters and actively monitor themselves. In the event of a hardware component failure there is no "blip on the radar screen", no delay for fail-over and no loss of system performance.

what about disk as tape? instead of using a tape rotation you use a disk rotation: you get history, off site storage, inexpensive media, fast restore.... the only downside i see is that they get angry if you drop them....

any thoughts?

We've been using Veritas Cluster Server (VCS) for Windows and Exchange for 3+ years (Solaris version even longer). We run two Windows server clusters: A three-node cluster that supports Exchange (Enterprise Ed) failover on two nodes and file/print services on two nodes, with one in common. Our two-node VCS cluster protects our email gateway server apps: Outlook Web Access, MailSweeper SMTP, and Blackberry Services.

By the way, we are a small organization: 180 staff total.

Over the past year, Exchange has been down in prime time about 2 hrs (our own goof up, not VCS; and the gateway not at all.

This solution requires an organization that can tolerate the very occassional 3-4 minute failover time in exchange for lots of benefits. One benefit is the ability to carry out invasive changes during work time while user services run on the alternative node. We did this recently to swap out a server main board. Another big benefit to us is administrator flexibility since both the Solaris and Windows admins can manage failovers. (We also use Veritas Volume Manager on both Unix and Windows so there are additional admin unifications there.)

We don't cluster SQLserver, but the agent is available. Clustering of Windows Printer services is trickiest and most fragile part of our configuration.

We are also looking at a "perfect" solution for Exchange DR mode at our Business Continuity (T-1 connected) site using Veritas Volume replicator and Global Cluster manager; this solution requires Volume Manager and VCS as prerequisites.

Hope this is useful.

Andy Colb

Replication is great for backup and recovery, but does not address the issues of disaster recovery, or archiving. There are a few products out that provide fairly elegant solutions with varying complexity. Tivoli Storage Manager (TSM) from IBM provides a nice utility for managing backups at the file level. It allows for online and offline disk and tape pools where backup flows through levels of storage. You can maintain the last n days of backed up documents in a disk storage while pushing lesser used documents onto tape for backup. At the same time you can define your DR tapes and archiving tapes which are manages and handled automatically for you. The only full backup performed is the first time the system is put into motion. From then on the system manages incremental backup and off-site storage as well as tape reclamation. TSM is a pretty sweet product. Since backups are handled at the file level you can even allow your users to restore accidental deleted or modified files through client software.
Unfortunately TSM is a bit of a bear to get a handle on. A company out of Colorado Springs, CO, STORServer has created a backup appliance, which is a combination of disk and tape storage utilizing TSM as it's management application. They have scripted a front end that is highly usable and removes all of the complexity of TSM. The setup of the system is typically less than a week. The system does come with a relevant price tag, but with the savings in tape usage over a year often pays for it self in tape reduction let alone time freed up managing the system.

Six months ago I was a college graduate with no network experience looking to learn and gain the skills I needed to succeed in the field. I do not consider myself an expert but I do know a thing or two about stabilizing a network. This reply is just a brief on some things we are doing to increase stability in our org.

When I first came into the organization (1000+), things were also a mess. Our alert system (Big Brother) would send us alerts on a daily basis telling us that something was going wrong with the system. Since then the number of alerts have significantly decreased thanks to rebuilds, repairs, and implementation of brick-level backups and redundancy.

We have several NAS systems handling the backups of our file servers and any brick-level backups need. Our implementation of the NAS systems provide us with the resources needed to reduce downtime and recover from catastrophe, though recovery time is still needed. They provide the option of recovering data from a snapshot of some point in time just in case any critical data was lost for some reason. RAIDs and clusters may provide redundancy but in such a case you will just have redundancy of lost data. That is where the backups can come in handy.

We have also recently implemented a Dell/EMC entry level SAN solution - our biggest investment into reaching stability yet. Among the systems running off it is a two node active/passive Exchange 2000 cluster on Win2k Advanced Server. Configured correctly, Microsoft's Cluster Service actually does a decent job doing what it's supposed to. The SAN has several RAID (1 & 5) sets with multiple luns, redundant power, and redundant fiber switch. Our Exchange servers are connected to the SAN via HBA cards. If you are looking for near zero downtime, you should look into this. You can even go as far as adding RAID sets to each node in the cluster if you wish.

Total redundancy is something everyone wishes they could have and if money were no object then it would be no problem. You should do a thorough cost-benefit analysis when pursuing this. Just remember that no matter how much redundancy you have, there is still Murphy's Law.

I use removable hard drives too. They are very nice for my weekly rotation.

However, I use tape for my archives.

Two sets are definitely not enough. Most professionals have one daily, one weekly, one monthly and one set per year to fall back to - often with more sets stored off-site. Also - are they stored in different locations ? What is the cost/gig compared to a very good tape unit ?

As previously mentioned, what about historical data: ie, last months database, last years payroll. Break out the tapes, baby, and restore the data.

While it did have a Dual Processor M'Board and a Dual SCSI bus with 13 HDD's installed it didn't have the possibility of using redundant Power Supplies.

Just one of the breaks when working with this type of stuff.

Col

Has anyone considered combining NAS devices with server imaging applications?

I have used a combination of V2i and Snap Appliance NAS. This combinations works very well. The V2i server image is compressed (2:1)and provides the ability to image the whole server, O/S and data or either as you wish. Restore is simple and fast. Combine this with the ability to replicate the Snap Appliance device to another, either local or remote, and you have a good basic solution that provides for fast backup and restore as well as DR.

We only re-image the O/S as part of change control, so normally only the data is re-imaged each time.

This thread will bounce all over the place (as you can already see) unless you can provide some specifics to your situation.

First, does your company actually have a Disaster Recovery plan in place? If not, you should get one going. It will include the processes of backup and data restoration germaine to this thread.

Secondly, is your company subject to any regulatory compliance such as HIPPA, GLBA, or SOX? This impacts your DR plan and backup requirements. E.g. archiving of data or email under one regulation can vary from another as can the lengths of time for archiving.

Thirdly, how many servers are involved and what is the cumulative size of critical data you need to recover in your situation?

This will allow the rest of us to provide better responses to you rather than expound whether SANs are better than NAS or tape, etc.

Marathon's software ties two standard Windows servers together into an FT platform for Windows apps just like the ones you are running. No failover (it's not a cluster), zero downtime, even online repairs. And no proprietary hardware. Your users will never notice a blip.