Why Tape Backups are Still Necessary

[seawolf]

This will probably be a somewhat contentious post, but so be it.

 

Tape should still be a part of EVERY backup routine. There, I've said it. And it's true.

 

I know there are many of you who think that disk-based backups are superior in every way, including speed, cost, reliability, and expandability. Some of you may think that tape backups are not just second-rate, but entirely useless in 2014 with virtualisation, failover clusters, SAN replication and Veeam backups. But...you would be wrong.

 

Even Google and Amazon still use tape backups for archiving, and it has saved their bacon more than once.

 

Official Gmail Blog: Gmail back soon for everyone

 

Why the Google Incident Proves Relevance of Tape Storage | B&L

 

As stated in the blog articles, one of the big life savers of tape is that by its nature it is off-line and can easily be store off-site. Failover clusters, replication, and automated real-time backups won't save you if all copies of files are deleted, corrupted, or otherwise destroyed.

 

But, I have multiple disk-based backups you say and then there are all of those inferiorities of tape you say. Well, some of those inferiorities are myth and disk-based backups aren't so portable when you are backing up TBs of data. Go over 4TB and you need a large and heavy RAID or JBOD array. Those aren't so portable. A bunch of LTO6 tapes - much more so.

 

http://www.storage-switzerland.com/Articles/Entries/2011/1/27_Breaking_The_Top_Four_Myths_Of_Tape_vs._Disk_Backup.html

 

And, it is likely that tape storage backup sizes will begin to increase rapidly in the near future with LTO8, LTO9 and beyond. Not only that, but tape loaders / libraries are dropping dramatically in price making such technology within the reach of SMEs and Education.

 

Disk-pushers, get reel: Even GOOGLE relies on tape

 

And, if you still aren't convinced of the value of tape, then there may be a Blu Ray backup solution in your future.

 

Facebook uses 10,000 Blu-ray discs to store 'cold' data | PCWorld

 

Regardless, it is critically important to keep at least two copies of your backups and at least one of them must be off-line and hopefully off-site.

[jamesfed]

I think the real thing here is that trusting in replication and duplication of live data as a backup system (using DFS-R, VM replicas or other means) is the false economy.

 

I consider our backups that go over from the SAN to the NAS box to be isolated as multiple versions are kept and at no time does the live data have any chance to influence the backups.

 

All the same, every 3 months a tape backup runs saving everything to long term media

[TheGoodGuy]

Tape backup restoration is known to have a high failure rate. I much prefer cloud backup due to the disaster proofing that it offers. However, I could see the potential for monthly archiving with the new 1tb disc being developed.

 

1TB per disc: Sony and Panasonic team up on next-gen Blu-ray | ExtremeTech

[Arthur]

I could see the potential for monthly archiving with the new 1TB disc being developed.

To backup a single 6TB HDD you would need 21 x 300GB discs.

 

It's going to be a long time before the 1TB discs are available to buy.

[seawolf]

To backup a single 6TB HDD you would need 21 x 300GB discs.

 

It's going to be a long time before the 1TB discs are available to buy.

 

LTO-6 holds 2.5TB uncompressed or 6.25TB compressed. The maximum compression won't be achievable except in rare cases, but two LTO-6 tapes could easily hold 6TB of data. As the largest HDD available is 4TB, a backup to disk would have to span two HDDs as well.

[robjduk]

tape backups are not required if you do your job properly and have a robust backup solution in place.

[seawolf]

Tape backup restoration is known to have a high failure rate.

 

Are you speaking from experience with tape restores or are you perhaps referring to the non-existent Gartner statistic that 71% of tape restores fail? The statistic that Gartner was quoted by Microsoft in pushing its DPM solution, but never provided the actual source (because it didn't exist, so I can't even say it was a mis-quote. Someone just full on made it up).

 

http://www.backupcentral.com/mr-backup-blog-mainmenu-47/13-mr-backup-blog/395-gartner-never-said-71-of-tape-restores-fail.html

 

I much prefer cloud backup due to the disaster proofing that it offers.

 

Cloud-based backup achieves the off-site requirement, but not the off-line requirement unless you are manually connecting or rotating your cloud backup target each time. Another weakness of cloud backup is backup and restore speed. Have you ever restored from a cloud-based backup? LTO-6 runs at 160Mb/s and most people don't have a connection that is as fast or faster than that. Cloud restores could take days or weeks in some cases. Now, 160Mb/s isn't lightning fast compared to 1Gb transfer rates from disk, but tape is meant to be a secondary offline/archival backup. So, backup to disk then back that up to tape, rotate the tape media and store off-site.

Edited March 16, 2014 by seawolf

[seawolf]

tape backups are not required if you do your job properly and have a robust backup solution in place.

 

Explain "doing your job properly" and what backup solution you have in place that can protect you adequately without tape. If someone has a new and better way that solves all of the problems off-line tape backups solve my ears are open.

[TheGoodGuy]

Thankfully I have never had to restore from a tape.

 

The cloud backup we use has a retention policy that we set ourselves (we chose 90 days but it can be unlimited). This means that ALL versions of a file are stored which gives extra protection against viruses etc.

 

Also the company that we use will ship a drive out to us in case of a disaster. We just have to pay the cost of the courier or pick it up ourselves (about 25 miles away).

[Jasbo]

Can you pm the name of this uber cloud provider you keep mentioning plz

[mrbios]

tape backups are not required if you do your job properly and have a robust backup solution in place.

 

Well that's a very arrogant and sweeping statement to make....

 

..anyway, the issue for me is the word "required", you've got 3 options, disk, tape, cloud. If you're going to the cloud, of course tape seems a bit redundant, but that all depends on your capabilities with the cloud....do you have the internet connection capable of backing up your incremental changes every day? etc etc. If you're going to disk, then it all depends on how crucial your data really is, where it's stored (for example if it's the in the same building as your live data and you dont use tapes, you're making a huge mistake), whether you even have the option of storing your disk backups away from the live data (some people may not have the luxury of setting up storage in an entirely separate building)

 

Overall, it's entirely down to how your situation pans out based on the above and many other factors. So there's no "doing your job properly" about it, doing your job properly, is ensuring you have a valid reliable backup if the worst should happen, end of.

[Arthur]

LTO-6 holds 2.5TB uncompressed or 6.25TB compressed.

Exactly my point! Why would you want the hassle of dealing with tens of Archival Discs if one (or two) LTO-6 tapes would be sufficient?

 

As the largest HDD available is 4TB

5TB and 6TB HDDs are now available from Toshiba and HGST respectively.

[seawolf]

Exactly my point! Why would you want the hassle of dealing with tens of Archival Discs if one (or two) LTO-6 tapes would be sufficient?

 

I assume you are referring to Blu Ray disks (ala Facebook's method of archival)? I agree that I don't see it as a a great backup media solution for that reason, but it is obviously viable.

 

5TB and 6TB HDDs are now available from Toshiba and HGST respectively.

 

I can't see any of these on my supplier's inventory lists, but they do appear to be on their way based on the media announcements. I expect they are going to be expensive though and tape libraries are still better for large archival jobs.

 

LTO-7 is also expected to land this year with 6.4TB raw backup capacity, 16TB compressed and data rates of 315Mb/s and 788Mb/s respectively. Whether disk-based or cloud-based, I just can't see a more cost-effective archival medium than Tape. Disk-based is not portable and cloud-based is expensive and slow for backing up 20TB+ of data.

[Arthur]

I assume you are referring to Blu Ray disks (ala Facebook's method of archival)?

I was referring to Sony and Panasonic's new 300GB "Archival Discs".

 

www.sony.net/SonyInfo/News/Press/201403/14-0310E/

Edited March 17, 2014 by Arthur

[seawolf]

I was referring to Sony and Panasonic's new 300GB "Archival Discs".

 

www.sony.net/SonyInfo/News/Press/201403/14-0310E/

 

Hadn't seen that press release or heard about these yet. I expect they will have a limited use case. Probably for archival of digital media (Videos and Pictures) exclusively for studios and independent film makers and photographers. Pretty useless in backing up a large storage array.

[matt40k]

From the point of view of security, "tapes" would be more secure in the sense it's physically disconnected once it's taken, so a remote hacker couldn't compromise the backup once it's been taken. It's why its often recommend taking a manual backup onto a CD\DVD\Bluray of your MIS \ Finance system in addition to your normal backup. It's a worse case scenario \ audit reason to do it.

 

Also, if you go down the tape route you need to ensure that you have at least two tape drives as the drives can get unaligned so restoration can't occur on other drives - normally you find this out too late when the drive dies, so you need at least two, one to do the backup and another to test the backup. I find tapes only really work in a managed environment and most people just outsource it to a "cloud" provider. So you basically go disk > cloud then they go disk > disk > tape

[zag]

I take your points, but I've had tape restores fail on my multiple times over the years and I just didnt think it was a reliable medium.

 

Ever since we moved to Hard disks, and then onto SSD I've never had a corrupted restore problem.

 

I use this for our external backups that we can take offsite or put in the fireproof safe, far more reliable imo

 

Edited March 18, 2014 by zag

[matt40k]

Not going to argue about best media type, if you're doing archives onto a removable device I think you're covering yourself. I don't trust usb drives, one drop and it's gone - not seen a external SSD yet however, so that might be a real option. Personally backing up onto DVD-R or a WORM tape at the end of term makes sense. From an audit point of view, once it's created, you can't edit it. I wouldn't intend to restore from it, but they are cheap, DVD-R are pennies and it covers you if you ask another school to hold it, just look at St Felix Middle that burnt down, the fireproof safe got melted into the rest of the building so "fireproof" isn't really "fireproof". DVD-R backups really are the absolute last line of defense and I don't see why you wouldn't do it. Pretty much every new machine comes with a writer, dvd-r a pennies. Order a pack then first week of the summer holiday, do a backup of the financial and MIS system use 7zip or something to compress and encrypt it (with a really rememberable password) and ask one of the local primaries to stash it in their safe.

[localzuk]

It really depends on the size of the data you need to backup. We can fit our entire backup on a 2TB disk. So, we bought 4TB disks for off-site backup, so we have plenty of expansion to work with.

 

We then have our day to day backup solution - a 16TB NAS in a different building well separated from the main building.

 

If we had more data, I'd possibly think about tape again, but it'd have to be a heck of a lot more to be honest.

[sonofsanta]

tape backups are not required if you do your job properly and have a robust backup solution in place.

 

What part of "building burnt to the ground" has anything to do with the way I do my job? As it happens, I'm covered if that happens thanks to my robust backup strategy - that uses LTO5 tapes.

 

Tapes are much smaller/easier to carry about than 3.5" external HDDs, more robust if dropped (which is to say, robust at all), cheaper to buy multiples of for the rotation, and more reliable in the long term - just because a HDD is sat in a cupboard somewhere doesn't mean it won't degrade and corrupt the data. Tapes are much better for long term storage in that regard, and we keep data for up to seven years.

 

We also use hard drives for the daily backups, because they're easier to restore from, with the weekly backups going onto tape (and the final week of each month being kept for a year, and the final week of July being kept for seven years). We also use Previous Versions on the file server to enable users to restore their own files in the short term. But I still want the peace of mind of off-site tapes.

 

SSDs may, once cost comes down, be the better solution - more robust than HDD, less prone to spontaneous bit decay, small and light - but the cost needs to come down a long way yet to cover the quantity we need for our rotation schedule.

[seawolf]

I take your points, but I've had tape restores fail on my multiple times over the years and I just didnt think it was a reliable medium.

 

Ever since we moved to Hard disks, and then onto SSD I've never had a corrupted restore problem.

 

I use this for our external backups that we can take offsite or put in the fireproof safe, far more reliable imo

 

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@zag - you have to remember that your circumstances are really quite rare and most people could not use external 512GB SSDs as their rotational backup media. It's just not feasible for most people. I couldn't even hold my two file servers on a 512GB SSD let along our 21 other VM servers. Then there are configuration backups from our firewalls, switches, etc. and...nope, not until there are some 6TB SSDs available for a reasonable cost.

[zag]

@zag - you have to remember that your circumstances are really quite rare and most people could not use external 512GB SSDs as their rotational backup media. It's just not feasible for most people. I couldn't even hold my two file servers on a 512GB SSD let along our 21 other VM servers. Then there are configuration backups from our firewalls, switches, etc. and...nope, not until there are some 6TB SSDs available for a reasonable cost.

 

I do understand, but those SSDs are credit card sized and don't suffer from dvd/tape rot.

 

As you know, I really do think the technology is at a tipping point where people can seriously consider backing up to solid state memory.

 

As for backing up 6tb... I think people should look at my blog post on that one

[seawolf]

As for backing up 6tb... I think people should look at my blog post on that one

 

I've seen that post, and ehem, most of us would not be able to get away with doing some of those things. I have a good relationship with our Media and Art teachers and doing some of these things would absolutely sink that. Perhaps in a primary school I could get away with it.

[sonofsanta]

I've seen that post, and ehem, most of us would not be able to get away with doing some of those things. I have a good relationship with our Media and Art teachers and doing some of these things would absolutely sink that. Perhaps in a primary school I could get away with it.

 

Indeed - resizing all images to 1080p for screen res? A 1080p 72dpi image printed at 300dpi for print quality isn't even 6" x 4". It'd destroy Photography.

 

Lord knows they don't need all 300 images from their camera at that size when they're only going to use half a dozen of them - but I don't know which ones they'll use and which ones they won't. All I can do is encourage them to be conscientous with it, but at the end of the day: storage is cheap, and I'm here to support them as users; they're not here to justify my lovely network. I have to work to their needs.

[Pottsey]

I do understand, but those SSDs are credit card sized and don't suffer from dvd/tape rot.

 

As you know, I really do think the technology is at a tipping point where people can seriously consider backing up to solid state memory.

 

As for backing up 6tb... I think people should look at my blog post on that one

SSD that are powered down for to long lose all the data stored. Higher end SSD's can retain data longer without power but all SSD's given time suffer in the same way as dvd/tape rot.

 

EDIT: Some SSDs can keep data for as little as 3 months without power. Those SSD you use have a warning on them not to be used as a sole backup.

Edited March 18, 2014 by Pottsey