John, > > You can take a single table and make it multiple physical files > (partitions) and backup those files at the same time. Say you have one > table that is 40 GB, but you spread it across 10 files of 4GB each, > spread across 10 different DASD volumes (disk drives). Instead of > backing up one 40 GB file, you can now backup ten 4GB files concurrently > (assuming you have 10 tape drives). No your backups run in 1/10 of the > time. This is where the tape system comes into play, instead of a human > taking 5 minutes to mount each tape (50 minutes total) a tape system > could have all 10 mounted in 5-10 minutes, a 40 minute savings in time > to get your backups done. >
40GB! Like who cares about 40GB. That's a typically small LUN (volume) in Unix and Wintel (my PC hard Drive is bigger than that). Using Logical Volume Manager RAID-0 a couple of TB of Oracle Database tables are striped across many LUNs, and these are backed up to tape with a degree of parallelism that would make most mainframe shops green with envy. We have Unix shops with Disk to Tape backup throughput requirements of 1-2GB/sec. Compare that to a maxed out VTS that struggles to get up to 400MB/sec. > All robotic tape system of any size will cost millions of dollars, not > matter whose it is. However, they save 10's of millions of dollars in > time and staffing, at least they are supposed to. > Interesting, millions of dollars for a 10 drive library. We'll have to tell ADIC, Quantum, IBM and Stortek to increase their list prices. Surprising as it may seem, those 100s of servers can get by without a Powderhorn class library. And as for 10's of millions of dollars of time and staffing, well that's an interesting argument in Asia where you can hire an educated and intelligent carbon based robots for around US$2K a month. Ron ---------------------------------------------------------------------- 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
