Having storage issues. Any replacement of Tape?

Hritam · New User Joined: 27 Jun 2005 Posts: 32 Location: India

Hi,
I got an issue in my project regarding the storage unit.
One of the job is processing and writing a file, in which I am expecting around 20 million records. And due to this we thought of using Tape instead of DASD. But there I got a serious performance Issue, its taking 5-6 hours for this process, which ideally should take around 1 hrs at the max. I shall appreciate if you help me to find a solution of this.
Let me know if you have any question regarding this.

Thanks,
Hritam

Robert Sample · Posted: Tue Jun 17, 2008 5:06 pm Post subject:

What's the JCL for the file look like? Adding buffers (BUFNO for QSAM, AMP=BUFND for VSAM) can make a huge difference in elapsed time. Other factors include blocking factor (use a large block size on tapes), application processing, system load, and hardware characteristics. And what's the LRECL, too? 20 million 20-byte records is a lot different than 20 million 2000-byte records!

dick scherrer · Posted: Tue Jun 17, 2008 7:34 pm Post subject:

Hello,

How many output volumes are written in the 5-6 hour run?

What device type is being written to (not tape or cart, but which device model number)? Your storage management people will know if this is not generally known.

What other "tape" media might be available (another question for the storage management people).

As Robert asked - what does the jcl look like?

Pedro

The replacement for tape was disk storage. There is a trade off between tape and disk: quantity vs. speed.

More questions:
what actions are you doing with the data? My concern is that you are require random access but are using a serial file.

gcicchet · Senior Member Joined: 28 Jul 2006 Posts: 653

Hi Hritam,
when you say it should take around 1 hour at the max, what is this based on, how long does it take to write to DASD ?

Gerry

expat · Posted: Sat Jun 21, 2008 4:27 pm Post subject:

What is the manufacturers throughput expectations for the tape devices.

What are the tape devices. and how are they connected to the mainframe ?

Virtual or real tape devices. If virtual what is the cache size ?