Re: Deduplication and Collocation
Back to client side dedupe, which we're about to deploy for a branch campus 90 miles away in Rockford IL. The data is sent from the clients in Rockford via tin cans and string to the TSM server in Chicago already dedpued. We're using source dedupe because the network bandwidth is somewhat limited. So if it is received into a DEVCLASS DISK stgpool, then I assume it is still deduped, because that's how it arrived. Then finally when it's migrated to tape, we've already established that it gets reinflated, and then you can collocate or not as you wish. But the question is, does this imply that deduped data CAN exist in random access DEVCLASS DISK stgpools if client-side dedupe is being used? I sure hope so, because that's what we're planning to do. Roger Deschner University of Illinois at Chicago rog...@uic.edu == You will finish your project ahead of schedule. === = (Best fortune-cookie fortune ever.) == On Tue, 21 Jun 2011, Paul Zarnowski wrote: Even if a FILE devclass has dedup turned on, when the data is migrated, reclaimed, or backed up (backup stgpool) to tape, then the files are reconstructed from their pieces. You cannot dedup on DISK stgpools. DISK implies random access disk - e.g., devclass DISK. FILE implies serial access disk - e.g., devclass FILE. But I think there is still an open question about collocation and deduplication. Deduplication must be done using FILE stgpools, but FILE stgpools CAN use collocation. I don't know what happens in this case. ..Paul At 02:38 PM 6/21/2011, Prather, Wanda wrote: If it is a file device class with dedup turned off, yes. -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:29 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Deduplication and Collocation So data is deduplicated in a disk storage pool but when it is written to tape the entire reconstructed file is written out? Is this the same for file device classes? -- Paul ZarnowskiPh: 607-255-4757 Manager, Storage Services Fx: 607-255-8521 719 Rhodes Hall, Ithaca, NY 14853-3801Em: p...@cornell.edu
Re: Deduplication and Collocation
As far as I know client site de-duplication will not work with primary storage pool DISK. It must be FILE as well like for server site de-duplication. Am I right? Grigori G. Solonovitch -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Roger Deschner Sent: Wednesday, June 22, 2011 9:37 AM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Deduplication and Collocation Back to client side dedupe, which we're about to deploy for a branch campus 90 miles away in Rockford IL. The data is sent from the clients in Rockford via tin cans and string to the TSM server in Chicago already dedpued. We're using source dedupe because the network bandwidth is somewhat limited. So if it is received into a DEVCLASS DISK stgpool, then I assume it is still deduped, because that's how it arrived. Then finally when it's migrated to tape, we've already established that it gets reinflated, and then you can collocate or not as you wish. But the question is, does this imply that deduped data CAN exist in random access DEVCLASS DISK stgpools if client-side dedupe is being used? I sure hope so, because that's what we're planning to do. Roger Deschner University of Illinois at Chicago rog...@uic.edu == You will finish your project ahead of schedule. === = (Best fortune-cookie fortune ever.) == On Tue, 21 Jun 2011, Paul Zarnowski wrote: Even if a FILE devclass has dedup turned on, when the data is migrated, reclaimed, or backed up (backup stgpool) to tape, then the files are reconstructed from their pieces. You cannot dedup on DISK stgpools. DISK implies random access disk - e.g., devclass DISK. FILE implies serial access disk - e.g., devclass FILE. But I think there is still an open question about collocation and deduplication. Deduplication must be done using FILE stgpools, but FILE stgpools CAN use collocation. I don't know what happens in this case. ..Paul At 02:38 PM 6/21/2011, Prather, Wanda wrote: If it is a file device class with dedup turned off, yes. -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:29 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Deduplication and Collocation So data is deduplicated in a disk storage pool but when it is written to tape the entire reconstructed file is written out? Is this the same for file device classes? -- Paul ZarnowskiPh: 607-255-4757 Manager, Storage Services Fx: 607-255-8521 719 Rhodes Hall, Ithaca, NY 14853-3801Em: p...@cornell.edu Please consider the environment before printing this Email. CONFIDENTIALITY AND WAIVER: The information contained in this electronic mail message and any attachments hereto may be legally privileged and confidential. The information is intended only for the recipient(s) named in this message. If you are not the intended recipient you are notified that any use, disclosure, copying or distribution is prohibited. If you have received this in error please contact the sender and delete this message and any attachments from your computer system. We do not guarantee that this message or any attachment to it is secure or free from errors, computer viruses or other conditions that may damage or interfere with data, hardware or software.
Re: Deduplication and Collocation
This is my understanding as well. I'm almost certain this is the case, though we have not yet used source dedup. ..Paul On Jun 22, 2011, at 3:34 AM, Grigori Solonovitch grigori.solonovi...@ahliunited.com wrote: As far as I know client site de-duplication will not work with primary storage pool DISK. It must be FILE as well like for server site de-duplication. Am I right? Grigori G. Solonovitch -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Roger Deschner Sent: Wednesday, June 22, 2011 9:37 AM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Deduplication and Collocation Back to client side dedupe, which we're about to deploy for a branch campus 90 miles away in Rockford IL. The data is sent from the clients in Rockford via tin cans and string to the TSM server in Chicago already dedpued. We're using source dedupe because the network bandwidth is somewhat limited. So if it is received into a DEVCLASS DISK stgpool, then I assume it is still deduped, because that's how it arrived. Then finally when it's migrated to tape, we've already established that it gets reinflated, and then you can collocate or not as you wish. But the question is, does this imply that deduped data CAN exist in random access DEVCLASS DISK stgpools if client-side dedupe is being used? I sure hope so, because that's what we're planning to do. Roger Deschner University of Illinois at Chicago rog...@uic.edu == You will finish your project ahead of schedule. === = (Best fortune-cookie fortune ever.) == On Tue, 21 Jun 2011, Paul Zarnowski wrote: Even if a FILE devclass has dedup turned on, when the data is migrated, reclaimed, or backed up (backup stgpool) to tape, then the files are reconstructed from their pieces. You cannot dedup on DISK stgpools. DISK implies random access disk - e.g., devclass DISK. FILE implies serial access disk - e.g., devclass FILE. But I think there is still an open question about collocation and deduplication. Deduplication must be done using FILE stgpools, but FILE stgpools CAN use collocation. I don't know what happens in this case. ..Paul At 02:38 PM 6/21/2011, Prather, Wanda wrote: If it is a file device class with dedup turned off, yes. -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:29 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Deduplication and Collocation So data is deduplicated in a disk storage pool but when it is written to tape the entire reconstructed file is written out? Is this the same for file device classes? -- Paul ZarnowskiPh: 607-255-4757 Manager, Storage Services Fx: 607-255-8521 719 Rhodes Hall, Ithaca, NY 14853-3801Em: p...@cornell.edu Please consider the environment before printing this Email. CONFIDENTIALITY AND WAIVER: The information contained in this electronic mail message and any attachments hereto may be legally privileged and confidential. The information is intended only for the recipient(s) named in this message. If you are not the intended recipient you are notified that any use, disclosure, copying or distribution is prohibited. If you have received this in error please contact the sender and delete this message and any attachments from your computer system. We do not guarantee that this message or any attachment to it is secure or free from errors, computer viruses or other conditions that may damage or interfere with data, hardware or software.
Re: Deduplication and Collocation
Agreed. AFAIK, the client-side dedup function is reliant on the dedup information in the storage pool where the data resides on the server. Which has to be a file pool, and deduped. -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Paul Zarnowski Sent: Wednesday, June 22, 2011 7:01 AM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Deduplication and Collocation This is my understanding as well. I'm almost certain this is the case, though we have not yet used source dedup. ..Paul On Jun 22, 2011, at 3:34 AM, Grigori Solonovitch grigori.solonovi...@ahliunited.com wrote: As far as I know client site de-duplication will not work with primary storage pool DISK. It must be FILE as well like for server site de-duplication. Am I right? Grigori G. Solonovitch -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Roger Deschner Sent: Wednesday, June 22, 2011 9:37 AM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Deduplication and Collocation Back to client side dedupe, which we're about to deploy for a branch campus 90 miles away in Rockford IL. The data is sent from the clients in Rockford via tin cans and string to the TSM server in Chicago already dedpued. We're using source dedupe because the network bandwidth is somewhat limited. So if it is received into a DEVCLASS DISK stgpool, then I assume it is still deduped, because that's how it arrived. Then finally when it's migrated to tape, we've already established that it gets reinflated, and then you can collocate or not as you wish. But the question is, does this imply that deduped data CAN exist in random access DEVCLASS DISK stgpools if client-side dedupe is being used? I sure hope so, because that's what we're planning to do. Roger Deschner University of Illinois at Chicago rog...@uic.edu == You will finish your project ahead of schedule. === = (Best fortune-cookie fortune ever.) == On Tue, 21 Jun 2011, Paul Zarnowski wrote: Even if a FILE devclass has dedup turned on, when the data is migrated, reclaimed, or backed up (backup stgpool) to tape, then the files are reconstructed from their pieces. You cannot dedup on DISK stgpools. DISK implies random access disk - e.g., devclass DISK. FILE implies serial access disk - e.g., devclass FILE. But I think there is still an open question about collocation and deduplication. Deduplication must be done using FILE stgpools, but FILE stgpools CAN use collocation. I don't know what happens in this case. ..Paul At 02:38 PM 6/21/2011, Prather, Wanda wrote: If it is a file device class with dedup turned off, yes. -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:29 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Deduplication and Collocation So data is deduplicated in a disk storage pool but when it is written to tape the entire reconstructed file is written out? Is this the same for file device classes? -- Paul ZarnowskiPh: 607-255-4757 Manager, Storage Services Fx: 607-255-8521 719 Rhodes Hall, Ithaca, NY 14853-3801Em: p...@cornell.edu Please consider the environment before printing this Email. CONFIDENTIALITY AND WAIVER: The information contained in this electronic mail message and any attachments hereto may be legally privileged and confidential. The information is intended only for the recipient(s) named in this message. If you are not the intended recipient you are notified that any use, disclosure, copying or distribution is prohibited. If you have received this in error please contact the sender and delete this message and any attachments from your computer system. We do not guarantee that this message or any attachment to it is secure or free from errors, computer viruses or other conditions that may damage or interfere with data, hardware or software.
Re: Deduplication and Collocation
Client side dedup is only done to a dedup storagepool which means the storagepool has to be a FILE type storagepool. Roger Deschner rog...@uic.edu 6/22/2011 2:37 AM Back to client side dedupe, which we're about to deploy for a branch campus 90 miles away in Rockford IL. The data is sent from the clients in Rockford via tin cans and string to the TSM server in Chicago already dedpued. We're using source dedupe because the network bandwidth is somewhat limited. So if it is received into a DEVCLASS DISK stgpool, then I assume it is still deduped, because that's how it arrived. Then finally when it's migrated to tape, we've already established that it gets reinflated, and then you can collocate or not as you wish. But the question is, does this imply that deduped data CAN exist in random access DEVCLASS DISK stgpools if client-side dedupe is being used? I sure hope so, because that's what we're planning to do. Roger Deschner University of Illinois at Chicago rog...@uic.edu == You will finish your project ahead of schedule. === = (Best fortune-cookie fortune ever.) == On Tue, 21 Jun 2011, Paul Zarnowski wrote: Even if a FILE devclass has dedup turned on, when the data is migrated, reclaimed, or backed up (backup stgpool) to tape, then the files are reconstructed from their pieces. You cannot dedup on DISK stgpools. DISK implies random access disk - e.g., devclass DISK. FILE implies serial access disk - e.g., devclass FILE. But I think there is still an open question about collocation and deduplication. Deduplication must be done using FILE stgpools, but FILE stgpools CAN use collocation. I don't know what happens in this case. ..Paul At 02:38 PM 6/21/2011, Prather, Wanda wrote: If it is a file device class with dedup turned off, yes. -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:29 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Deduplication and Collocation So data is deduplicated in a disk storage pool but when it is written to tape the entire reconstructed file is written out? Is this the same for file device classes? -- Paul ZarnowskiPh: 607-255-4757 Manager, Storage Services Fx: 607-255-8521 719 Rhodes Hall, Ithaca, NY 14853-3801Em: p...@cornell.edu
Re: Deduplication and Collocation
Tape pools are not de-duped, so that is not a consideration. On Tue, Jun 21, 2011 at 13:17, Mark Mooney mmoo...@aisconsulting.net wrote: Hello, I had a student ask me today What happens if you have collocation turned on for a storage pool that you are deduplicating? I did not know what to answer because in my mind I thought well, if the data is collocated then I need to have a copy of that data on that client's tape, otherwise I am going to be mounting another client's tape to get back a de-duped piece of data which would negate the collocation I'm looking at the redbooks for this but I only see 6.1 and in 6.2 they added client side dedup as well (which I also have questions about) Can anyone shed some light on this? Thanks! Mooney -- Andy Carlson --- Gamecube:$150,PSO:$50,Broadband Adapter: $35, Hunters License: $8.95/month, The feeling of seeing the red box with the item you want in it:Priceless.
Re: Deduplication and Collocation
Doesn't it undup when it goes to tape? Or am I still living in 5.5 and thinking in VTL dedup? -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:17 PM To: ADSM-L@VM.MARIST.EDU Subject: [ADSM-L] Deduplication and Collocation Hello, I had a student ask me today What happens if you have collocation turned on for a storage pool that you are deduplicating? I did not know what to answer because in my mind I thought well, if the data is collocated then I need to have a copy of that data on that client's tape, otherwise I am going to be mounting another client's tape to get back a de-duped piece of data which would negate the collocation I'm looking at the redbooks for this but I only see 6.1 and in 6.2 they added client side dedup as well (which I also have questions about) Can anyone shed some light on this? Thanks! Mooney IMPORTANT: E-mail sent through the Internet is not secure. Legg Mason therefore recommends that you do not send any confidential or sensitive information to us via electronic mail, including social security numbers, account numbers, or personal identification numbers. Delivery, and or timely delivery of Internet mail is not guaranteed. Legg Mason therefore recommends that you do not send time sensitive or action-oriented messages to us via electronic mail. This message is intended for the addressee only and may contain privileged or confidential information. Unless you are the intended recipient, you may not use, copy or disclose to anyone any information contained in this message. If you have received this message in error, please notify the author by replying to this message and then kindly delete the message. Thank you.
Re: Deduplication and Collocation
So data is deduplicated in a disk storage pool but when it is written to tape the entire reconstructed file is written out? Is this the same for file device classes? -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Andrew Carlson Sent: Tuesday, June 21, 2011 8:22 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: Deduplication and Collocation Tape pools are not de-duped, so that is not a consideration. On Tue, Jun 21, 2011 at 13:17, Mark Mooney mmoo...@aisconsulting.net wrote: Hello, I had a student ask me today What happens if you have collocation turned on for a storage pool that you are deduplicating? I did not know what to answer because in my mind I thought well, if the data is collocated then I need to have a copy of that data on that client's tape, otherwise I am going to be mounting another client's tape to get back a de-duped piece of data which would negate the collocation I'm looking at the redbooks for this but I only see 6.1 and in 6.2 they added client side dedup as well (which I also have questions about) Can anyone shed some light on this? Thanks! Mooney -- Andy Carlson --- Gamecube:$150,PSO:$50,Broadband Adapter: $35, Hunters License: $8.95/month, The feeling of seeing the red box with the item you want in it:Priceless.
Re: Deduplication and Collocation
Dedup only works in TSM storage pools that reside on disk (specifically devtype=FILE pools). If you have data that goes to a dedup pool, then gets migrated off to tape, it is reduped (rehydrated, reinflated, whatever you want to call it.) So collocation will still be in effect for that pool. -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:17 PM To: ADSM-L@VM.MARIST.EDU Subject: [ADSM-L] Deduplication and Collocation Hello, I had a student ask me today What happens if you have collocation turned on for a storage pool that you are deduplicating? I did not know what to answer because in my mind I thought well, if the data is collocated then I need to have a copy of that data on that client's tape, otherwise I am going to be mounting another client's tape to get back a de-duped piece of data which would negate the collocation I'm looking at the redbooks for this but I only see 6.1 and in 6.2 they added client side dedup as well (which I also have questions about) Can anyone shed some light on this? Thanks! Mooney
Re: Deduplication and Collocation
If it is a file device class with dedup turned off, yes. -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:29 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Deduplication and Collocation So data is deduplicated in a disk storage pool but when it is written to tape the entire reconstructed file is written out? Is this the same for file device classes? -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Andrew Carlson Sent: Tuesday, June 21, 2011 8:22 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: Deduplication and Collocation Tape pools are not de-duped, so that is not a consideration. On Tue, Jun 21, 2011 at 13:17, Mark Mooney mmoo...@aisconsulting.net wrote: Hello, I had a student ask me today What happens if you have collocation turned on for a storage pool that you are deduplicating? I did not know what to answer because in my mind I thought well, if the data is collocated then I need to have a copy of that data on that client's tape, otherwise I am going to be mounting another client's tape to get back a de-duped piece of data which would negate the collocation I'm looking at the redbooks for this but I only see 6.1 and in 6.2 they added client side dedup as well (which I also have questions about) Can anyone shed some light on this? Thanks! Mooney -- Andy Carlson --- Gamecube:$150,PSO:$50,Broadband Adapter: $35, Hunters License: $8.95/month, The feeling of seeing the red box with the item you want in it:Priceless.
Re: Deduplication and Collocation
And that's why storage pool planning is very important. The less re-duping, hydrating, inflating you do the better. Client data to a non-deduped (I guess that would be a duped) pool that migrates to a deduped pool. But backup stgpool before the migration happens to avoid the re. This is where I expect I'll be corrected: as long as the backup stg happens before the deduplication process on the file devtype storage pool the reduping won't have to happen. (we weren't really talking about collocated copy pools were we?) But then you wouldn't have a file devtype pool migrating to tape very often anyway would you? And if you did, that would only be in an emergency situation (i.e., you ran out of room on disk). And in that case why would you collocate? Ah, the words of someone that used to think he knew what he was talking about! Kelly J. Lipp Elbert Colorado 719-531-5574 -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Prather, Wanda Sent: Tuesday, June 21, 2011 12:27 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Deduplication and Collocation Dedup only works in TSM storage pools that reside on disk (specifically devtype=FILE pools). If you have data that goes to a dedup pool, then gets migrated off to tape, it is reduped (rehydrated, reinflated, whatever you want to call it.) So collocation will still be in effect for that pool. -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:17 PM To: ADSM-L@VM.MARIST.EDU Subject: [ADSM-L] Deduplication and Collocation Hello, I had a student ask me today What happens if you have collocation turned on for a storage pool that you are deduplicating? I did not know what to answer because in my mind I thought well, if the data is collocated then I need to have a copy of that data on that client's tape, otherwise I am going to be mounting another client's tape to get back a de-duped piece of data which would negate the collocation I'm looking at the redbooks for this but I only see 6.1 and in 6.2 they added client side dedup as well (which I also have questions about) Can anyone shed some light on this? Thanks! Mooney
Re: Deduplication and Collocation
Cool, Thanks :) I have questions about client dedup. Do you know of any redbook detail on that? Thanks, Mooney Prather, Wanda wprat...@icfi.com wrote: Dedup only works in TSM storage pools that reside on disk (specifically devtype=FILE pools). If you have data that goes to a dedup pool, then gets migrated off to tape, it is reduped (rehydrated, reinflated, whatever you want to call it.) So collocation will still be in effect for that pool. -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:17 PM To: ADSM-L@VM.MARIST.EDU Subject: [ADSM-L] Deduplication and Collocation Hello, I had a student ask me today What happens if you have collocation turned on for a storage pool that you are deduplicating? I did not know what to answer because in my mind I thought well, if the data is collocated then I need to have a copy of that data on that client's tape, otherwise I am going to be mounting another client's tape to get back a de-duped piece of data which would negate the collocation I'm looking at the redbooks for this but I only see 6.1 and in 6.2 they added client side dedup as well (which I also have questions about) Can anyone shed some light on this? Thanks! Mooney
Re: Deduplication and Collocation
https://www-304.ibm.com/support/docview.wss?context=SSGSG7lang=allrs=2077wv=1loc=en_UScs=UTF-8uid=swg27018576q1=tste_webcastdc=DA410 -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:53 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Deduplication and Collocation Cool, Thanks :) I have questions about client dedup. Do you know of any redbook detail on that? Thanks, Mooney Prather, Wanda wprat...@icfi.com wrote: Dedup only works in TSM storage pools that reside on disk (specifically devtype=FILE pools). If you have data that goes to a dedup pool, then gets migrated off to tape, it is reduped (rehydrated, reinflated, whatever you want to call it.) So collocation will still be in effect for that pool. -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:17 PM To: ADSM-L@VM.MARIST.EDU Subject: [ADSM-L] Deduplication and Collocation Hello, I had a student ask me today What happens if you have collocation turned on for a storage pool that you are deduplicating? I did not know what to answer because in my mind I thought well, if the data is collocated then I need to have a copy of that data on that client's tape, otherwise I am going to be mounting another client's tape to get back a de-duped piece of data which would negate the collocation I'm looking at the redbooks for this but I only see 6.1 and in 6.2 they added client side dedup as well (which I also have questions about) Can anyone shed some light on this? Thanks! Mooney
Re: Deduplication and Collocation
Even if a FILE devclass has dedup turned on, when the data is migrated, reclaimed, or backed up (backup stgpool) to tape, then the files are reconstructed from their pieces. You cannot dedup on DISK stgpools. DISK implies random access disk - e.g., devclass DISK. FILE implies serial access disk - e.g., devclass FILE. But I think there is still an open question about collocation and deduplication. Deduplication must be done using FILE stgpools, but FILE stgpools CAN use collocation. I don't know what happens in this case. ..Paul At 02:38 PM 6/21/2011, Prather, Wanda wrote: If it is a file device class with dedup turned off, yes. -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:29 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Deduplication and Collocation So data is deduplicated in a disk storage pool but when it is written to tape the entire reconstructed file is written out? Is this the same for file device classes? -- Paul ZarnowskiPh: 607-255-4757 Manager, Storage Services Fx: 607-255-8521 719 Rhodes Hall, Ithaca, NY 14853-3801Em: p...@cornell.edu
Re: Deduplication and Collocation
Thank you Wanda! Much Appreciated! -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Prather, Wanda Sent: Tuesday, June 21, 2011 9:09 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: Deduplication and Collocation https://www-304.ibm.com/support/docview.wss?context=SSGSG7lang=allrs=2077wv=1loc=en_UScs=UTF-8uid=swg27018576q1=tste_webcastdc=DA410 -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:53 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Deduplication and Collocation Cool, Thanks :) I have questions about client dedup. Do you know of any redbook detail on that? Thanks, Mooney Prather, Wanda wprat...@icfi.com wrote: Dedup only works in TSM storage pools that reside on disk (specifically devtype=FILE pools). If you have data that goes to a dedup pool, then gets migrated off to tape, it is reduped (rehydrated, reinflated, whatever you want to call it.) So collocation will still be in effect for that pool. -Original Message- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Mark Mooney Sent: Tuesday, June 21, 2011 2:17 PM To: ADSM-L@VM.MARIST.EDU Subject: [ADSM-L] Deduplication and Collocation Hello, I had a student ask me today What happens if you have collocation turned on for a storage pool that you are deduplicating? I did not know what to answer because in my mind I thought well, if the data is collocated then I need to have a copy of that data on that client's tape, otherwise I am going to be mounting another client's tape to get back a de-duped piece of data which would negate the collocation I'm looking at the redbooks for this but I only see 6.1 and in 6.2 they added client side dedup as well (which I also have questions about) Can anyone shed some light on this? Thanks! Mooney
