Comments on: Executing the savlib command twice

By: The Most-Watched IT Questions: February 22, 2011 - ITKE Community Blog

The Most-Watched IT Questions: February 22, 2011 - ITKE Community Blog — Tue, 22 Feb 2011 06:33:13 +0000

[...] 8. The community’s consensus is that there is nothing to worry about when executing the savlib command twice. [...]

By: Featured Member: Pdraebel - ITKE Community Blog

Featured Member: Pdraebel - ITKE Community Blog — Tue, 22 Feb 2011 06:03:50 +0000

[...] Executing the savlib command twice [...]

By: woodengineer

woodengineer — Thu, 10 Feb 2011 17:05:53 +0000

I noticed that you are using SAVACT(*NO). Have you confirmed that the data you want is indeed being saved to tape?

By: danthedane

danthedane — Thu, 10 Feb 2011 14:53:54 +0000

“This is so we could have the current backup in house. “
If you have enough disk-space, I recommend you to do a save to an imagecatalog (a ‘virtual tapedrive’). Restore from a virtual tapedrive is lightning fast.

We do all backup to virtual tapes, and thereafter we DUPTAPs to physical tapes with low priority during daytime. Thus our nightly backup always finishes since we created multipe virtual tapes for our multi-tapevolume-backup. We thereby have ‘released’ our system for production in daytime, since we no longer have the morning-message “Insert next tape..”.

DanF

Find more on this solution in the IBM Infomation Center (look for ‘virtual backup media’).

By: pdraebel

pdraebel — Thu, 10 Feb 2011 09:04:54 +0000

Dupliating the tape would seem the best option, but you should have 2 drives available, so it comes down to the possibilities of your hardware.

By: Featured Member: HMSSL2K - ITKE Community Blog

Featured Member: HMSSL2K - ITKE Community Blog — Thu, 10 Feb 2011 06:12:26 +0000

[...] Executing the savlib command twice [...]

By: tomliotta

tomliotta — Wed, 09 Feb 2011 21:21:07 +0000

…and should be faster than the tape backup (no tape wait).

When streaming tape drives starting taking hold, the advantage started dropping. Nowadays, it’s not uncommon to faster saves to tape than to disk. The LTO-4 drives can often outperform disks.

But it depends on elements such as DASD capacity, RAID configuration, controller buffer sizes and some other elements.

With streaming tape drives, “tape wait” isn’t necessarily much of a factor. If the system is capable of supplying data at a rate that keeps the tape occupied (and controller buffers can make a significant difference), waits may disappear.

Tom

By: pgmbob

pgmbob — Wed, 09 Feb 2011 18:56:32 +0000

Another, possibly faster option is SAVLIB to a SAVEFILE. The process can submit the SAVSAVF to the tape, and SAVSAVF to another tape.
The SAVF can eliminate the need for the second copy and should be faster than the tape backup (no tape wait). There is a copy on the system in the savefile. The TAPE goes to offsite location
The tip is to make sure you have enough disk capacity for the savefile.
Create a library to save the savefile(s) The savfiles can be named for the library they contain.
I run a list of libraries to a file.
The CLP reads the file, CRTSAVF or CLRSAVF and does a SAVLIB to *SAVF for each library found. (no new libraries missed)

The Tape job makes a file of the SAVEILE(s) in the save library.
Read this file to SAVSAVF to the tape.

The SAVF can also be saved on another server.
We use this for nightly backup where a night operator is not available or needed to swap tapes.

By: charliebrowne

charliebrowne — Tue, 08 Feb 2011 18:02:12 +0000

The DUPTAP command would seem to be the best option as you can submit that to batch and run with a priority so as to not have much impact on the rest of the system.
Also, this would not cause any object lock conflicts by doing a 2nd save.

By: as400pcfiletransfer16

as400pcfiletransfer16 — Tue, 08 Feb 2011 17:49:58 +0000

No we doing the SAVLIB with the SAVACT parm set to *NO. The program that is running the savlib command was written a few years ago and never really changed. With the execption of the hardware.