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Back Up Questions
Posted: Thu Nov 01, 2007 11:28 am
by WRXWagon2112
We are about to institute an off-site tape rotation for our backups and my boss has a few questions (more like hang-ups).
1. Compressed vs Uncompressed
He's an old-school guy who is wary of compression. Does anyone know of any stats or sites that can speak to the reliability of compressed backups versus uncompressed backups.
2. Off-site tape storage vendors
We've gotten a quote from Iron Mountain but he's not thrilled with it. Who are the vendors that y'all use and would you recommend them? We're looking at 2-3 tapes a week using a GFS rotation. Say about 30 tapes max stored off-site at any one time.
Any advice would be most appreciated.
--Alan
Re: Back Up Questions
Posted: Thu Nov 01, 2007 11:41 am
by sirwilliam
WRXWagon2112 wrote:We are about to institute an off-site tape rotation for our backups and my boss has a few questions (more like hang-ups).
1. Compressed vs Uncompressed
He's an old-school guy who is wary of compression. Does anyone know of any stats or sites that can speak to the reliability of compressed backups versus uncompressed backups.
2. Off-site tape storage vendors
We've gotten a quote from Iron Mountain but he's not thrilled with it. Who are the vendors that y'all use and would you recommend them? We're looking at 2-3 tapes a week using a GFS rotation. Say about 30 tapes max stored off-site at any one time.
Any advice would be most appreciated.
--Alan
#1) We used to use DDS4 compressed DAT tape backups...they worked fine. We have since gone from that to full USB HD backups due to size.
#2) Never used anyone other than our own companies to do it so never had any quotes or limitations or requirements.
Re: Back Up Questions
Posted: Thu Nov 01, 2007 11:46 am
by ElZorro
WRXWagon2112 wrote:1. Compressed vs Uncompressed
Don't have any emperical information on this one, but I'd say it probably doesn't increase your risk of a failed recovery - if you don't compress a bit-level error will effect a smaller portion of data, if you do compress you put less wear-and-tear on the tape.
WRXWagon2112 wrote:2. Off-site tape storage vendors
My last IT department used Iron Mountain (which is probably why you're coming up with it). They worked well. The question is, why are you sending off site a couple times a week? The idea of off-site is that if the building burns you can reach back into the wayback machine and recover. Is your data that mission critical that anything more than a two or three day loss is going to destroy you? If so - you probably want a fully redundant datacenter at another location. It is common to send tapes offsite once a week or twice a month. An alternative, if your company has a second site close by (Herndon, Chantilly, Reston, etc) send a copy over there once a week and a copy to Iron Mountain once a week. Make sure it is miles away. When I worked county government IT we'd send our offsite backups to the jail/sherrif's office down the road. Policy changed when a tornado almost took out both buildings...
Posted: Thu Nov 01, 2007 11:57 am
by Sabre
1.) Compression is 100% safe and it helps with data security. This is NOT to say that you should not use encryption. Your best bet for safe data (as you are handing your companies data to a third party who should not be trusted) is to compress and encrypt the data. You have more chance of a tape going bad than you do with something in the compression going bad. I have never had issues with compression in all my years as an admin/engineer.
If he is so concerned, tell him to have the backup do a confirmation/compare after the backup is done
2.) The two places that I have worked for (Gov agency and large corp) that did off site backup both used Iron Mountain. We never had any issues with them, but I know they have been in the media before with issues

Posted: Thu Nov 01, 2007 12:04 pm
by Mr Kleen
we use Iron Mountain here at Department of Ed. my experience with them is good but I don't pay the bills and I'm not the primary backup guy.
Re: Back Up Questions
Posted: Thu Nov 01, 2007 12:17 pm
by Sabre
[quote="ElZorro"]The question is, why are you sending off site a couple times a week?[quote]
NASA does technically 3 off site backups...
1.) Daily tapes go to a close by building
2.) The above tapes are rotated out to Iron Mountain daily (so you always have yesterdays within "arms reach").
3.) Mirror setup through dedicated DS3's to
these badboys in a different area of the US.
Excessive? Yes. Should it be? Yep!
Posted: Thu Nov 01, 2007 12:58 pm
by WRXWagon2112
El Zorro - Well the idea is that our full weeklies will be sent off-site and stored for five weeks. After that, they are returned to us in exchange for another full weekly backup. Every fourth full weekly backup is considered a monthly and sent off-site for storage for a year. So essentially we'll have a year's worth of full backups in storage and we'll rotate through weekly tapes in between the monthly backups. Hence the two tapes every week.
The idea of using another one of our buildings is a great idea. My only concern is with regards to a formal COOP (continuity of operations plan). Depending on who's evaluating the plan they may insist on a formal vendor to verify that tapes are being managed in a secure facility, etc., etc. But I really like the idea of "free" storage.
--Alan
Re: Back Up Questions
Posted: Thu Nov 01, 2007 4:36 pm
by avriette
WRXWagon2112 wrote:
1. Compressed vs Uncompressed
He's an old-school guy who is wary of compression. Does anyone know of any stats or sites that can speak to the reliability of compressed backups versus uncompressed backups.
uncompressed. if you compress, and you get one bit wrong, you lose the whole thing. if you don't compress, and you lose a bit, maybe this "a" is actually a "b". But you're not going to lose the whole archive.
WRXWagon2112 wrote:
2. Off-site tape storage vendors
We've gotten a quote from Iron Mountain but he's not thrilled with it. Who are the vendors that y'all use and would you recommend them? We're looking at 2-3 tapes a week using a GFS rotation. Say about 30 tapes max stored off-site at any one time.
I've used their services at four shops in the last ten years. They are absolutely peerless. It costs a lot, but dammit, they're the best. I've been to the datacenters and silos of some of their competition (there are a few out in the rt. 28 area by waxpool, for obvious reasons), and it's just amateur stuff.
Go with Iron Mountain. Optical is probably a better bet than magnetic these days, but that seems to change every other year or so.
Good luck.