I'm not fully aware of how the DD replicates data, but if you have 15-20TB/day being written to your main DD, and that data is then replicated to the off-site DD, how much data is actually replicated? With a 1Gbs connection, you could hit values up to 360GB/s hour (expecting 100MB/s which should be theoretically possible, but it's usually lower than that on a 1Gbs connections) which means 8.6TB per 24 hours. So the data is both deduplicated and compressed before you send it offsite? Does the DD do the dedup within the same box, or require a separate box for dedup? You're also running with the same risk as the previous poster, you're relying entirely on the fact that your DD setup wont break. Is this how the DD is sold? (Buy 2 DD's, replicate between them and you're safe) ? I know it's (like the previous poster stated) always a question about costs vs mitigating risks, but if I got to choose, I'd rather have fast restores from my main site and slow from my offsite, as long as I can restore the data. Instead of having fast from main, fast from off, but there's a chance I might not be able to do restore at all.
If DD claims they have "data invunerability" I'd really like to see how they hit 100% protection, since it would be the first system in the world to actually have managed to secure that last 0,0001% risk ;) RAID usually was "secure" until someone made an error, put in a blank disk and forgot to rebuild :) Best Regards Daniel Daniel Sparrman Exist i Stockholm AB Växel: 08-754 98 00 Fax: 08-754 97 30 daniel.sparr...@exist.se http://www.existgruppen.se Posthusgatan 1 761 30 NORRTÄLJE -----"ADSM: Dist Stor Manager" <ADSM-L@VM.MARIST.EDU> skrev: ----- Till: ADSM-L@VM.MARIST.EDU Från: Shawn Drew <shawn.d...@americas.bnpparibas.com> Sänt av: "ADSM: Dist Stor Manager" <ADSM-L@VM.MARIST.EDU> Datum: 09/28/2011 22:26 Ärende: Re: [ADSM-L] Ang: Re: [ADSM-L] Ang: Re: [ADSM-L] vtl versus file systems for pirmary pool We average between 15-20TB/day at our main site, and that goes directly to a single DD890 (no random pool) . single-pool, file devclass, NFS mounted on 2x10GB crossover connections. Replicates over a 1gb WAN link to another DD890. (I spent all the money on the DD boxes, I didn't have enough left over for 10GB switches!) That other DD890 backs up another 7-10TB/day, replicating to the main site (bi-directional replication). All with file devclasses and there is not more than a one hour lag in replication by the time I show up in the morning. TSM doesn't have to do replication or backup stgpools anymore, so I can actually afford to do full db backups every day now. (I was doing an incremental scheme before) IBM has a similar "recommended" configuration with their Protectier solution, so they do support a single pool, backend replication solution. Data Domain also claims that "data invulnerability" which should catch any data corruption issue as soon as the data is written, and not later, when you try and restore. Regards, Shawn ________________________________________________ Shawn Drew Internet daniel.sparr...@exist.se Sent by: ADSM-L@VM.MARIST.EDU 09/28/2011 02:13 AM Please respond to ADSM-L@VM.MARIST.EDU To ADSM-L cc Subject [ADSM-L] Ang: Re: [ADSM-L] Ang: Re: [ADSM-L] vtl versus file systems for pirmary pool How many TB of data is common in this configuration? In a large environment, where databases are 5-10TB each and you have a demand to backup 5-10-15-20TB of data each night, this would require you to have 10Gbs for every host, something that would also cost a penny. Especially since the DD needs to be configured to have the throughput to write all those TB within a limited amount of time. Does the DD do de-dup within the same box (meaning, can I have 1 box that handles normal storage and does de-dup) or do I need a 2nd box? And the same issue also arises with the filepool, you're moving alot of data around completely unnecessary every day when u do reclaim. If I'm right, it also sounds like (in your description from the previous mails) you're not only using the DD for TSM storage. That sounds like putting all the eggs in the same basket. Best Regards Daniel Daniel Sparrman Exist i Stockholm AB Växel: 08-754 98 00 Fax: 08-754 97 30 daniel.sparr...@exist.se http://www.existgruppen.se Posthusgatan 1 761 30 NORRTÄLJE -----"ADSM: Dist Stor Manager" <ADSM-L@VM.MARIST.EDU> skrev: ----- Till: ADSM-L@VM.MARIST.EDU Från: "Allen S. Rout" <a...@ufl.edu> Sänt av: "ADSM: Dist Stor Manager" <ADSM-L@VM.MARIST.EDU> Datum: 09/27/2011 18:55 Ärende: Re: [ADSM-L] Ang: Re: [ADSM-L] vtl versus file systems for pirmary pool On 09/27/2011 12:02 PM, Rick Adamson wrote: > The bigger question I have is since the file based storage is > native to TSM why exactly is using a file based storage > not supported? Not supported by what? If you've got a DD, then the simplest way to connect it to TSM is via files. Some backup apps require something that looks like a library, in which case you'd be buying the VTL license. FWIW, if you're already in DD space, you're paying a pretty penny. The VTL license isn't chicken feed, I agree, but it's not a major component of the total cost. - Allen S. Rout This message and any attachments (the "message") is intended solely for the addressees and is confidential. If you receive this message in error, please delete it and immediately notify the sender. Any use not in accord with its purpose, any dissemination or disclosure, either whole or partial, is prohibited except formal approval. The internet can not guarantee the integrity of this message. BNP PARIBAS (and its subsidiaries) shall (will) not therefore be liable for the message if modified. Please note that certain functions and services for BNP Paribas may be performed by BNP Paribas RCC, Inc.
