Re: Questions about vtl useage
All good advice. I would add a couple of points: When checking performance on a VTL (especially deduped) be sure to check both write and read speeds. Some VTLs will ingest very well, but when you are running reclamation or large restores (especially multiples), you may be limited by the re-hydration (recombobulation?) capabilities of the device. In the same light, when you are running reclamation on deduped storage, the same recombobulation must occur to feed the data back to TSM before it can be re-written and deduped again. Since TSM controls the filepool dedup and knows where all the blocks are, this process of rebuilding the data and re-writing and re-de-duping is mostly done with pointers. Bob. -Original Message- From: ADSM: Dist Stor Manager [mailto:ads...@vm.marist.edu] On Behalf Of Prather, Wanda Sent: Wednesday, June 16, 2010 10:42 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Questions about vtl useage "Pick Carefully" is indeed, the best advice. If all you need is "additional storage", there are many configurations of either VTL or disk/filepool that you can choose. Filepools are very easy to manage in TSM. VTL's are more trouble to manage in some ways (you'll likely be defining & managing dozens of paths), and there are more parts that can break. The 1 thing that would force you to choose a VTL, is a requirement for LAN-FREE support, which can only be done to a tape or tape-emulating device. There are 2 things that would force you to choose filepool: either wanting to run your TSM server as a VM (and I'm not saying that is a good idea anyway), or wanting to use client-side dedup. If none of those issues apply to your situation, there are lots of combinations you can use. A VTL that dedups; a disk filepool with or without TSM software deduplication: you can use disk of your own with a VTL gateway that dedups; there are companies that will sell you a VTL that dedups but behaves like plain disk so you can still use TSM with a filepool for client-side dedup, and you can use a NAS device that dedups but looks like plain disk to TSM so you can still use TSM with a filepool. SO, now that I"ve added to the confusion: Here are the big MISTAKES I've seen people make over the last 4 years buying VTLs (or some combination of the above stuff): 1) Buying a solution that only solves today's problem. You need a solution that will solve your current problem, and will adapt to the problem you will hit 2 years from now, whatever that is most likely to be. For instance, if there is ANY likelihood that you would face a big bump in storage requirements in 2 years, for heaven's sake don't buy a VTL that can't expand to fit that need. Make sure you understand how you would adapt what you plan to buy, in case of a) needing more storage in the future, b) needing more throughput in the future, c) adding to the number of TSM servers you plan to run in the future, etc. There isn't really a good way to repurpose a VTL if you outgrow it. 2) Not figuring out what your throughput requirements are. Some VTL's are quite limited in throughput. Don't assume that because it's disk, it will be fast. Figure out your throughput needs as well as your space needs, and make the vendor configure to meet both requirements. 3) Not figuring on software or expansion costs. Make sure you get bids for at LEAST 3 years of your support costs, including the software costs. Also find out what it would cost if you have to expand the puppy later by xx terabytes. Some of the VTL's are licensed by TB, some are not. 4) Buying something you don't thoroughly understand. VTL's are not magic. If you buy disk instead of a VTL, you have to deal with spindles and buses and controllers and HBA's and firmware. If you buy a VTL, you have to deal with spindles and buses and controllers and HBA's and firmware at the back end, plus servers and HBA's and firmware and software on the front end. If someone offers you a VTL, LOOK at the hardware that makes it up. If someone offered you the same package as a straight disk array, would you be happy to buy it? If not, why would you want it as part of a VTL? If after you consider all these issues you aren't comfortable that a VTL is the right choice, or you just can't decide, buy disk. It's more flexible and you can always reconfigure it, repurpose it, move things around in your disk farm as you want. If you decide you need a VTL later, you can add a VTL gateway in front of your own disk. Wanda -Original Message- From: ADSM: Dist Stor Manager [mailto:ads...@vm.marist.edu] On Behalf Of Huebner,Andy,FORT WORTH,IT Sent: Monday, June 14, 2010 9:29 AM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Questions about vtl useage We currently use an older VTL for the primary pools and you might find it hard to tell the difference between i
Re: Questions about vtl useage
"Pick Carefully" is indeed, the best advice. If all you need is "additional storage", there are many configurations of either VTL or disk/filepool that you can choose. Filepools are very easy to manage in TSM. VTL's are more trouble to manage in some ways (you'll likely be defining & managing dozens of paths), and there are more parts that can break. The 1 thing that would force you to choose a VTL, is a requirement for LAN-FREE support, which can only be done to a tape or tape-emulating device. There are 2 things that would force you to choose filepool: either wanting to run your TSM server as a VM (and I'm not saying that is a good idea anyway), or wanting to use client-side dedup. If none of those issues apply to your situation, there are lots of combinations you can use. A VTL that dedups; a disk filepool with or without TSM software deduplication: you can use disk of your own with a VTL gateway that dedups; there are companies that will sell you a VTL that dedups but behaves like plain disk so you can still use TSM with a filepool for client-side dedup, and you can use a NAS device that dedups but looks like plain disk to TSM so you can still use TSM with a filepool. SO, now that I"ve added to the confusion: Here are the big MISTAKES I've seen people make over the last 4 years buying VTLs (or some combination of the above stuff): 1) Buying a solution that only solves today's problem. You need a solution that will solve your current problem, and will adapt to the problem you will hit 2 years from now, whatever that is most likely to be. For instance, if there is ANY likelihood that you would face a big bump in storage requirements in 2 years, for heaven's sake don't buy a VTL that can't expand to fit that need. Make sure you understand how you would adapt what you plan to buy, in case of a) needing more storage in the future, b) needing more throughput in the future, c) adding to the number of TSM servers you plan to run in the future, etc. There isn't really a good way to repurpose a VTL if you outgrow it. 2) Not figuring out what your throughput requirements are. Some VTL's are quite limited in throughput. Don't assume that because it's disk, it will be fast. Figure out your throughput needs as well as your space needs, and make the vendor configure to meet both requirements. 3) Not figuring on software or expansion costs. Make sure you get bids for at LEAST 3 years of your support costs, including the software costs. Also find out what it would cost if you have to expand the puppy later by xx terabytes. Some of the VTL's are licensed by TB, some are not. 4) Buying something you don't thoroughly understand. VTL's are not magic. If you buy disk instead of a VTL, you have to deal with spindles and buses and controllers and HBA's and firmware. If you buy a VTL, you have to deal with spindles and buses and controllers and HBA's and firmware at the back end, plus servers and HBA's and firmware and software on the front end. If someone offers you a VTL, LOOK at the hardware that makes it up. If someone offered you the same package as a straight disk array, would you be happy to buy it? If not, why would you want it as part of a VTL? If after you consider all these issues you aren't comfortable that a VTL is the right choice, or you just can't decide, buy disk. It's more flexible and you can always reconfigure it, repurpose it, move things around in your disk farm as you want. If you decide you need a VTL later, you can add a VTL gateway in front of your own disk. Wanda -Original Message- From: ADSM: Dist Stor Manager [mailto:ads...@vm.marist.edu] On Behalf Of Huebner,Andy,FORT WORTH,IT Sent: Monday, June 14, 2010 9:29 AM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Questions about vtl useage We currently use an older VTL for the primary pools and you might find it hard to tell the difference between it and disks. With the deduping VTLs out there the amount of storage needed will be reduced. Pick carefully if you go the dedup route. There are major speed differences depending on in-line vs. post processing. Check the archives, there are plenty of threads on collocation and cartridge size when using a VTL. We are using 4 year old FalconStor VTLs with about 300TB stored. 2 crashes, no other trouble. We do use slightly undersized disk pools to frontend the VTLs. Andy Huebner -Original Message- From: ADSM: Dist Stor Manager [mailto:ads...@vm.marist.edu] On Behalf Of Lee, Gary D. Sent: Monday, June 14, 2010 7:55 AM To: ADSM-L@VM.MARIST.EDU Subject: [ADSM-L] Questions about vtl useage Tsm server v5.5.4 running on suse sles9 under zvm 5.3. We are in need of expanding our storage. Currently have an ibm 8100. The disk is cheap enough, but the licensing for additional storage is outrageous. We are thin
Re: Questions about vtl useage
We are using the 8100 because it is here. The 8100 is shared across the mainframe. z/os for all administrative data, db2, vsam etc. All z/os backups ar done to tape as well. However, the university is getting an ERP solution, and the remaining candidates are sunguard banner, and peoplesoft. Finally, there is a distinct anti-mainframe wind blowing here. I give it five years tops. Gary Lee Senior System Programmer Ball State University phone: 765-285-1310 -Original Message- From: ADSM: Dist Stor Manager [mailto:ads...@vm.marist.edu] On Behalf Of Remco Post Sent: Monday, June 14, 2010 12:12 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: [ADSM-L] Questions about vtl useage Hi, On 14 jun 2010, at 14:54, Lee, Gary D. wrote: > Tsm server v5.5.4 running on suse sles9 under zvm 5.3. > > We are in need of expanding our storage. Currently have an ibm 8100. The > disk is cheap enough, but the licensing for additional storage is outrageous. > I'd say that a ds8100 is way overkill for TSM usage. DS5000 is way more suitable, and a lot less expensive. > We are thinking of switching to using a vtl for onsite storage and doing away > with our onsite tape. > Tape has one advantage: idle tapes are almost cost-free. Idle data sitting on disk still consumes power. Of course, if the amount of data is small enough (few TB) a disk-only solution makes sense. And of course, if your DR requirements are that you need access to first byte to be less than a second > Are any folks out there using vtl, and if so what kinds and what has been > your experience? > > I currently have about 3 tB of onsite tape, looking to at least double that > when we pick up the exchange 2007 environment. > 3 TB is peanuts. I'd say, buy a DS3000 (or comparable) dedicated to TSM. Will be way cheaper than any VTL solution. BTW, where do you keep the backups of all other data on your ds8100? > Thanks for any information. > > > Gary Lee > Senior System Programmer > Ball State University > phone: 765-285-1310 > -- Met vriendelijke groeten/Kind Regards, Remco Post r.p...@plcs.nl +31 6 248 21 622
Re: Questions about vtl useage
Hi, On 14 jun 2010, at 14:54, Lee, Gary D. wrote: > Tsm server v5.5.4 running on suse sles9 under zvm 5.3. > > We are in need of expanding our storage. Currently have an ibm 8100. The > disk is cheap enough, but the licensing for additional storage is outrageous. > I'd say that a ds8100 is way overkill for TSM usage. DS5000 is way more suitable, and a lot less expensive. > We are thinking of switching to using a vtl for onsite storage and doing away > with our onsite tape. > Tape has one advantage: idle tapes are almost cost-free. Idle data sitting on disk still consumes power. Of course, if the amount of data is small enough (few TB) a disk-only solution makes sense. And of course, if your DR requirements are that you need access to first byte to be less than a second > Are any folks out there using vtl, and if so what kinds and what has been > your experience? > > I currently have about 3 tB of onsite tape, looking to at least double that > when we pick up the exchange 2007 environment. > 3 TB is peanuts. I'd say, buy a DS3000 (or comparable) dedicated to TSM. Will be way cheaper than any VTL solution. BTW, where do you keep the backups of all other data on your ds8100? > Thanks for any information. > > > Gary Lee > Senior System Programmer > Ball State University > phone: 765-285-1310 > -- Met vriendelijke groeten/Kind Regards, Remco Post r.p...@plcs.nl +31 6 248 21 622
Re: Questions about vtl useage
We currently use an older VTL for the primary pools and you might find it hard to tell the difference between it and disks. With the deduping VTLs out there the amount of storage needed will be reduced. Pick carefully if you go the dedup route. There are major speed differences depending on in-line vs. post processing. Check the archives, there are plenty of threads on collocation and cartridge size when using a VTL. We are using 4 year old FalconStor VTLs with about 300TB stored. 2 crashes, no other trouble. We do use slightly undersized disk pools to frontend the VTLs. Andy Huebner -Original Message- From: ADSM: Dist Stor Manager [mailto:ads...@vm.marist.edu] On Behalf Of Lee, Gary D. Sent: Monday, June 14, 2010 7:55 AM To: ADSM-L@VM.MARIST.EDU Subject: [ADSM-L] Questions about vtl useage Tsm server v5.5.4 running on suse sles9 under zvm 5.3. We are in need of expanding our storage. Currently have an ibm 8100. The disk is cheap enough, but the licensing for additional storage is outrageous. We are thinking of switching to using a vtl for onsite storage and doing away with our onsite tape. Are any folks out there using vtl, and if so what kinds and what has been your experience? I currently have about 3 tB of onsite tape, looking to at least double that when we pick up the exchange 2007 environment. Thanks for any information. Gary Lee Senior System Programmer Ball State University phone: 765-285-1310 This e-mail (including any attachments) is confidential and may be legally privileged. If you are not an intended recipient or an authorized representative of an intended recipient, you are prohibited from using, copying or distributing the information in this e-mail or its attachments. If you have received this e-mail in error, please notify the sender immediately by return e-mail and delete all copies of this message and any attachments. Thank you.
Questions about vtl useage
Tsm server v5.5.4 running on suse sles9 under zvm 5.3. We are in need of expanding our storage. Currently have an ibm 8100. The disk is cheap enough, but the licensing for additional storage is outrageous. We are thinking of switching to using a vtl for onsite storage and doing away with our onsite tape. Are any folks out there using vtl, and if so what kinds and what has been your experience? I currently have about 3 tB of onsite tape, looking to at least double that when we pick up the exchange 2007 environment. Thanks for any information. Gary Lee Senior System Programmer Ball State University phone: 765-285-1310
