Been there, done that. - Advantage of building your own pool is that you can expand it whenever you want just by adding disk. CDL's on the market mostly have an upper limit on the TB they support. - You'll need to pre-allocate the volumes as mentioned before, but that's easy if you use the new 5.3 options on DEFINE VOLUME as mentioned in previous post. - Disadvantage of using your own pool is that the CDL's have built-in compression, like the tape drives do. Slows down the throughput a bit because it's done in software, but at least it's done outboard of TSM. So if you build your own pool, you'll need to plan on doing your compression on the client end.
________________________________ From: ADSM: Dist Stor Manager on behalf of Orin Rehorst Sent: Wed 10/18/2006 2:58 PM To: ADSM-L@VM.MARIST.EDU Subject: Re: Library out of space. Time for disks? I could use an external drive rack, build a RAID array, and use it to replace my primary tapepool, correct? What would be the disadvantages of that vs. a VTL? TIA Orin Rehorst -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On Behalf Of Thorneycroft, Doug Sent: Monday, October 16, 2006 10:18 AM To: ADSM-L@VM.MARIST.EDU Subject: Re: Library out of space. Time for disks? That's what we are doing. Our primary is a 6.4 TB VTL. So far, it's working very well. Excellent performance. Main concern is if the device fails, how long will it take to restore all those terabytes of primary storage from offsite volumes. -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] Behalf Of Orin Rehorst Sent: Monday, October 16, 2006 8:02 AM To: ADSM-L@VM.MARIST.EDU Subject: Library out of space. Time for disks? Our IBM 3583 tape lib is out of space. What do you think of this idea? Acquire disk-based appliance i.e. 3 TB. Use it for primary. Use 3583 for off site tapes only. Please advise. TIA Orin Rehorst