Re: Virtual tape cost question
Tim Hare wrote: [...] We're trying to evaluate switching to Tape Mount Management versus virtual tape. This post is not about the pros or cons of doing it; rather we're trying to analyze what some of the costs are. [...] That's the point. IMHO you *cannot* skip the proscons analysis. It's quite obvious, that virtual tape system (I'm talking about IBM or STK solutions now) costs more than real tape solutions since the same amount of drives, robots and medias could hold the same amount of data written natively. At least in theory. In practice, the main feature you get with virtual tape is convenience and flexibility. How much worth is it ? Well, id depends on your environment (the more systems, the more important), you budget constraints, your system setup, your operations skills. There is no strict formula or some treshold. I think the only advice you can get is to ask proper questions, like the following: - how many systems/sysplexes do you have - how is organized your Tape Mgmt System (one common vs several separated db's). - are you able to get rid of jobs writing small amounts of data directly to tape - I mean HSM and/or TMM. - what are your DR requirements and DR facilities (i.e. your own DR centre connected through DWDM links) - is your operations staff smart enough to easily manage manual vary on/off the drives across LPARs according to scheduled backup sessions or current needs. Caution: IBM ATAM or CA-MIA could do the work. - what's your amount of data to be kept on the tapes and what amount of data is being written to tape everyday. - what is tape activity during the day (recalls, reads) - what are your demands on performance (note native drives are usually faster than virtual drives). HTH -- Radoslaw Skorupka Lodz, Poland -- BRE Bank SA ul. Senatorska 18 00-950 Warszawa www.brebank.pl Sd Rejonowy dla m. st. Warszawy XII Wydzia Gospodarczy Krajowego Rejestru Sdowego, nr rejestru przedsibiorców KRS 025237 NIP: 526-021-50-88 Wedug stanu na dzie 01.01.2007 r. kapita zakadowy BRE Banku SA (w caoci opacony) wynosi 118.064.140 z. W zwizku z realizacj warunkowego podwyszenia kapitau zakadowego, na podstawie uchwa XVI WZ z dnia 21.05.2003 r., kapita zakadowy BRE Banku SA moe ulec podwyszeniu do kwoty 118.760.528 z. Akcje w podwyszonym kapitale zakadowym bd w caoci opacone. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Virtual tape cost question
I don't know if the rules of this list allow cost discussion - but I'm not asking for specific numbers, and I'm trying to avoid being specific about the vendor, so maybe it will slide? We're trying to evaluate switching to Tape Mount Management versus virtual tape. This post is not about the pros or cons of doing it; rather we're trying to analyze what some of the costs are. We already have a virtual tape system, leased, so as part of our analysis we asked the vendor to tell us cost figures for the virtual tape box. What we got back was about 20% of the total lease cost. This doesn't make sense to me - I figured the virtual tape components, being basically a multi-processor computer and a disk array, would cost more than the robotic tape components. Am I wrong in this? If anyone has actual cost figures for their virtual tape box separately, could you give me a ballpark of what the ratio of the cost of the virtual compontents to the tape components should be so I can do a sanity check on what I'm hearing? Basically, I'm trying to determine whether the vendor is lowballing the cost figure to influence whether or not we include a virtual tape box on our next lease... Thanks Tim Hare Senior Systems Programmer Florida Department of Transportation (850) 414-4209 -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Virtual tape cost question
On Fri, 8 Jun 2007 10:24:32 -0400, Tim Hare wrote: If anyone has actual cost figures for their virtual tape box separately, could you give me a ballpark of what the ratio of the cost of the virtual compontents to the tape components should be so I can do a sanity check on what I'm hearing? I'm not following what you're asking, but I've been trying to complete an evaluation of a robotic tape library compared to virtual tape on disk and just plain old DASD. The robotic tape library I looked at is also virtual, but is backed by physical tape. The costs to purchase a robotic tape library with about 250 cart capacity is just over $400K. The cost to purchase 15TB of DASD or a virtual tape solution backed by DASD is around $200K. I realize the tape solution offers a much larger capacity (and we would only use about 20% of its capacity), but I couldn't find a smaller industrial strength tape library option. Maintenance costs for the tape library around about $50K/year. Maintenance costs for either DASD solution is about $20K/year. I'm still working on the power numbers, but a preliminary look is the robotic tape library will use about 20% - 25% of the power the DASD solutions will use. I've still got to put this into dollar terms to get an idea of how long it will take to justify the cost difference, but I'm sure it's going to work out to be decades. There are other variations on this too. I'm trying to get numbers on adding some SATA drives to an existing Clarrion and attaching via a Luminex gateway device too. But those numbers are also looking to be in the $200K range. It's a lot harder to get power numbers on this configuration since the disk will be housed in an existing array. Lots of options. I started this analysis thinking a robotic tape library was the way to go, but I've changed my mind. I can't see how anyone can justify physical tape anymore. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Virtual tape cost question
I started this analysis thinking a robotic tape library was the way to go, but I've changed my mind. I can't see how anyone can justify physical tape anymore. Most virtual tape systems eventually write to physical tape as they internally perform hierarchical storage management. There's an OS that does HSM functions on a bunch of disk, and when the disk space gets full, the datasets representing virtual tape volumes are written off to physical tape. The robotic tape library I looked at is also virtual, but is backed by physical tape. The costs to purchase a robotic tape library with about 250 cart capacity is just over $400K. The cost to purchase 15TB of DASD or a virtual tape solution backed by DASD is around $200K. That is the cost of a robotic tape library _plus_ the virtual tape storage box with it, if I am reading you right. What we're looking at is the cost of _just_ the robotic tape library in conjunction with DASD we already own, versus the robotic tape + virtual tape solution. Since we have the capacity on our DASD to provide a disk buffer for the sequential datasets we currently create on tape it's hard to see the benefit of going to a virtual tape rather than just a sequential dataset on disk. The backups and migrated copies of these datasets will go to physical, not virtual tape. Physical tape transported offsite via vehicle we believe to be cheaper than PPRC or offsite tape devices connected via channel extenders (and of course high-speed networks). But that's not part of my original question either, I'm just trying to find out whether the virtual tape component being 20% of the total cost is legit or not. Tim Hare Senior Systems Programmer Florida Department of Transportation (850) 414-4209 -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Virtual tape cost question
Since we have the capacity on our DASD to provide a disk buffer for the sequential datasets we currently create on tape it's hard to see the benefit of going to a virtual tape rather than just a sequential dataset on disk. Is your 'disk buffer' on your enterprise disk? If so, how much does that cost you? You may have it available now, but there is still a cost there. Does it force you to buy more enterprise disk sooner than you would have? Is it mirrored? Do you chargeback for your disk usage? Things to think about.Good luck. Jeffrey Deaver, Engineer Systems Engineering [EMAIL PROTECTED] 651-665-4231(v) 651-610-7670(p) -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Virtual tape cost question
On Fri, 8 Jun 2007 13:42:25 -0400, Tim Hare wrote: Most virtual tape systems eventually write to physical tape as they internally perform hierarchical storage management. There's an OS that does HSM functions on a bunch of disk, and when the disk space gets full, the datasets representing virtual tape volumes are written off to physical tape. You can have it any way you want. You can have virtual tape systems backed by disk. It just looks like a tape device to the OS even though it's really disk. The robotic tape library I looked at is also virtual, but is backed by physical tape. The costs to purchase a robotic tape library with about 250 cart capacity is just over $400K. The cost to purchase 15TB of DASD or a virtual tape solution backed by DASD is around $200K. That is the cost of a robotic tape library _plus_ the virtual tape storage box with it, if I am reading you right. Yes, Robotic library and VTL software together. But that's not part of my original question either, I'm just trying to find out whether the virtual tape component being 20% of the total cost is legit or not. My quote was a swag so isn't line item. I don't know what the hardware vs software costs are. Sorry. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
