Server backup strategy; SAN or NAS?

[sicsicsic]

We have a handful of servers storing different types of data from exchange information to images to SQL databases. Recently, one of the servers took a huge hit in a power outage and lost 3 drives - it has been rebuilding for weeks.

I had a set of LTO2 tapes storing about 1.4 TB of data and was unsuccessful in restoring the data from them even though Backup Exec showed the job as successful, but that's a different story.

Planning for future disaster recovery I was looking into either a NAS or a SAN server. From my research on these it seems the NAS would be more appropriate for storing data from these servers as a backup since it is put on the network as oppose to being locally added in respect to the SAN. Does this sound reasonable?

I am looking for a way to immediately have a backup of all the data across these servers, so in essence whenever data is written to one it is also mirrored to the storage device. I am also upgrading the tape backup to LTO 3 and the latest Backup Exec to keep a redundant copy in that format as well.

Any advice or further knowledge on this is wonderfully appreciated.

Edit: This may need to be moved to storage or another appropriate forum. My apologies.

 

[Jamsan]

What's your budget? Depending on how much you're looking to spend, I'd look into a lower end iSCSI SAN from a decent provider (Dell Equallogic, Left Hand, NetApp, etc.). This allow you present storage to each server (as many as you'd like) and it will appear as another volume. Store your important information on there, and it'll be directly placed on the SAN (not internally to the server). The SAN's are usually highly reliable (RAID 50, dual power supplies, multiple NICs, multiple controllers, hot spares, etc.), so suffering a complete failure of the array is unlikely (but I wouldn't bet my money on it).

From there, I'd recommend using Backup Exec to backup directly to disk (either local storage if you have it available, or something like a Dell DL2200). This will allow for much faster backup and restore times. From there, you can backup to tape for off-site storage and archiving. This will cost you a nice penny, but it will give you peace of mind that a single failure (like with your RAID array) will cause your company to potentially lose all of it's data.

 

[degibson]

If you actually want disaster recovery, you want neither SAN nor NAS. You want an entirely different provider, in another state (assuming US), in another power distribution region.

If you're just looking for beefier backup infrastructure, the most cost-effective strategy is nearly always a properly-administered RAID system. The details depend on how much capacity you need, in what volume you buy your disks, etc. Then again, if you don't have the time/energy/interest/people/expertise/whatever to organize your own RAID-based systems, there are a lot of commercial less-cost-effective but much easier options as well. The most important thing about that domain is making sure you have an enforceable service agreement.

And to quote this:

I am looking for a way to immediately have a backup of all the data across these servers...

Don't fool yourself. There's always a delay between live and backup data. Unless you're doing distributed commit, e.g., as is done in some distributed storage environments, there will be a time delay between new data appearing and it showing up on a backup site.

 

[kevnich2]

My recommendation is some type of imaging software that runs on the servers and backs up to a centralized NAS system. These typically run every 15-60 minutes. If you get a system that does de-duplication technology, this would be ideal. Your backup window would be whatever duration you choose. We use this to backup all of our servers in 15-30 min windows. It allows us full bare metal recovery in case of server failure and fast file recovery as it's disk based. I don't like tapes, too error prone and takes too long for recovery.

I would also look into a system that has the capability to do off-site backups, say nightly. This way even if your building goes up in flames, your data is still safe.

 

[Bashbelly]

Data Dedup Appliance. Data Domain highly recommended. Can be FC or TCP/IP for connectivity.

 

[Texashiker]

I had a set of LTO2 tapes storing about 1.4 TB of data and was unsuccessful in restoring the data from them even though Backup Exec showed the job as successful, but that's a different story.

Personally, I have never been a fan of tape backup. Once something gets set as a standard, its difficult to change, regardless of how bad it actually is.

My backups here at the office are through an a couple of external USB hard drives that plug into the server. I live in a hurricane prone area, so I want a backup solution that is durable, easy to transport, somewhat inexpensive, and stays under our control. If we have a hurricane, I backup the server to the external drives, give 1 drive to the company director, and I take one of the other drives with me.

Beside for hurricanes, the server is backed up daily to the external drive. Evey few days a copy of the backup image is copied to another drive, or to another server.

 

[imagoon]

I live in a hurricane prone area, so I want a backup solution that is durable, easy to transport, somewhat inexpensive, and stays under our control

Then tapes meet your needs perfectly.

Thing about external HDD's: Make this scenario work with your set up: "I need to retrieve the excel file we have been updating daily as it was 8 weeks ago. Julie in accounting accidentally deleted some key information and saved the file."

I can do that with tapes. Can you do that with 2 USB HDDs?

I can also backup well over 5000MB/min can USB do that?

Tapes are not bad. I can transport 40 Terabytes of data in a briefcase if I needed to.

 

[sicsicsic]

I haven't got a chance to read through all of these yet but wanted to express my appreciation for the responses.

Thanks!

 

[theevilsharpie]

Thing about external HDD's: Make this scenario work with your set up: "I need to retrieve the excel file we have been updating daily as it was 8 weeks ago. Julie in accounting accidentally deleted some key information and saved the file."

I can do that with tapes. Can you do that with 2 USB HDDs?

Yes.

I can also backup well over 5000MB/min can USB do that?

500MB/min is about 8.3MB/s. Even the slowest USB hard drives have no problems achieving those speeds.

 

[imagoon]

Yes.



500MB/min is about 8.3MB/s. Even the slowest USB hard drives have no problems achieving those speeds.

Add an order of magnitude there buddy.

Also care to elaborate your "yes?" Maybe if your a tiny small business with only a few gig of data, but come up to the multiterabyte companies and show me how it works, while making it as fast, as reliable and as cheap please.

 

[theevilsharpie]

Add an order of magnitude there buddy.

Oops. Didn't see the extra '0' :$ I was wondering why your tapes were so slow :hmm:

High-end tape systems certainly have sequential write speeds going for them, but that's it. Need to restore from a base snapshot and several incrementals? Be prepared to wait a few minutes between seeks.

Also care to elaborate your "yes?" Maybe if your a tiny small business with only a few gig of data, but come up to the multiterabyte companies and show me how it works, while making it as fast, as reliable and as cheap please.

Modern disk backup systems typically rely on a base snapshot of the disk, and then an infinite series of incrementals. Unless a huge amount of data is changing every backup period, I can usually keep the base image and several weeks of snapshots on a single USB drive. Move up to a NAS with several terabyte disks in it, and I could easily store several months worth of snapshots.

And to top it all off, if all you need to do is recover an Excel file, the restore will be substantially faster than on a disk-based backup system.

 

[imagoon]

Oops. Didn't see the extra '0' :$ I was wondering why your tapes were so slow :hmm:

High-end tape systems certainly have sequential write speeds going for them, but that's it. Need to restore from a base snapshot and several incrementals? Be prepared to wait a few minutes between seeks.



Modern disk backup systems typically rely on a base snapshot of the disk, and then an infinite series of incrementals. Unless a huge amount of data is changing every backup period, I can usually keep the base image and several weeks of snapshots on a single USB drive. Move up to a NAS with several terabyte disks in it, and I could easily store several months worth of snapshots.

And to top it all off, if all you need to do is recover an Excel file, the restore will be substantially faster than on a disk-based backup system.

Ok now that I see where you are going I can make a "smarter" response. The first comment I would make is I use tapes primarily for offsite (BCP, building burns down and my SAN is at the bottom of a smoking crater etc) and to a lesser extent grabbing older files. My daily turn over is about 40 or so gig a day so in my case I would start to fill up the disk based systems at a "decent clip" so my typical approach is to keep incrementals for only a certain amount of time 3 months or so before I refresh the image back down to a flat image. The tapes are offsited weekly so going back a year to "weekly" backups is pretty easy. After that I tell people "sorry but we only have quarterly backups after a year" etc. This is what executive management approved so that is the direction I went.

I personally would be a bit nervous to have to many weeks of "incrementals" sitting on a disk unit though. Granted some do it better than others and use a decent single instance store and a good database to back it. My issue with that is making sure that if you have a total loss event, you can actually restore from the "blob" that is on the disk. Some apps store the database separate from the backup blog and if you fail to back up the database you either a) lose everything [crap programs] or b) are stuck waiting for the app to rebuild and index the blob. [Enterprise programs.]

Anyway I don't discount pure disk backups completely, I just personally prefer the "cheapness" of offsiting. Pickup an LTO5 tape for around $40 and having about 1.2TB of data on it that I can send to the off-site storage facility makes be feel warm and fuzzy inside. Esp since the tape can be pretty man handled and make it just fine. I even had them survive floods. [they make a machine that can unspool the flooded tape, spritz it with distilled water, run it through a dryer and then wind it back in to a new cartridge if the old one is rusted.] Hard drives I am not quite sure would survive that as well.

Anyway rambling above.

PS in case it isn't clear I do prod > disk > tape. Disk is my staging areas / recent restore point. The disks themselves never leave the building.

 

[Emulex]

double-take
hp lefthand or VTL

if you are in hurricane prone area - 2DC may not be enough. maybe need 3DC to reach far enough away given how crazy some of the last biggies were.

anyways lefthand VSA.

or virtualize everything (esxi essentials) and get veaam to do snapshot async replication to a destination esxi server over some comcast high speed wan

 

[Jeff7181]

Disk to disk by itself is not great. Disk to disk to tape is better. Disk to disk with deduplication and replication would be my preferred choice but it doesn't always fit the bill.

Deduplication doesn't work well on already compressed data and when you're working with 5 TB of deduplicated compressed data, it's difficult to afford a network connection to replicate that data off-site.

 

[Griffinhart]

Disk to disk by itself is not great. Disk to disk to tape is better. Disk to disk with deduplication and replication would be my preferred choice but it doesn't always fit the bill.

This would be my opinion as well.

Disk to Disk alone is only good to protect data from accidental deletions or server crashes. It would do very little to prevent a true distaster such as flood, fire or other problems that can threaten your data center.

Adding Tape archival on top of it is really the minimum you want. It's still much better than traditional tape only backups, but still requires the same tape management.

Disk to Disk with Data Dedup then replicating the data off-site is the way I would go.

Last year I did a pretty comprehensive risk/cost comparision of options for the company I was contracting for. After taking into account man hours, risk, hardware costs, monthly costs of off-site archival services (Iron Mountain Tape management), It was surprising how much sense using local disk to disk with cloud based replication made.

Traditional Disk to Tape backups, in the end, were the least cost effective when you factored in the costs of tape management including off-site storage. They also came with the highest risk of data loss/theft.

Barracuda Networks has a decent solution. Iron Mountain offers a very competitive option with the LiveVault service they have.

 

[gscone]

I surprised no one mentions web backup to a site like carbonite..

 

[Griffinhart]

Carbonite and other pure cloud services are nice, without some sort of appliance locally, you lose a lot of functionality as well as granular restore abilities. Carbonite doesn't support Revisioning and Mozy only goes back 30 days. They are fine for Mom and Pop size organization, but I wouldn't use it for more than a very small organization.

 

[Emulex]

compliance forbids using non-pci compliant backup services in the cloud. plus the business model isn't proven imo.

Just colo a lefthand and snap-sync it.

 

[kevnich2]

Try crashplan.com - it's what I use for my stuff. Gives you multiple backup options with a single program. I have it configured for disk to close offsite to cloud based. All of it's encrypted with my own encryption key. Backup happens as often as I prefer and file increments are also kept as long as I prefer. Good price as well. I can even take out the cloud based and just backup to other friends, I just prefer the cloud based just in case there's something that happens in our city. It pretty much protects me from all possible disasters while at the same time making restores as quickly as I need them to be.

And yes, I have used it several times to restore accidentally deleted or modified files - this scenario usually happens several times a week actually. Hasn't failed me in 2 years.