RE: physical / virtual tape backup file at a time -- MIDRANGE-L

Hi Adrienne

You will probably find the save process is quicker and more spaceefficient if you go the SAVRST* route using object connect, albeitthat it might take you a little more time to set up and get working.

In your case, FTP requires that you save the file to a SAVF first,thereby using your valuable limited disk space, and then send thefile. If you do go this route be sure to use DTACPR(*MEDIUM) assuggested by John as it can save quite a bit of space and will alsoreduce your transmission time.

On the other hand, the SAVRST* operation will use some disk spacewhile being transmitted, but my observations are that it does notmake a complete copy of the object prior to transmission but insteadas each chunk is saved it is transmitted and the space re-used forsaving the next chunk; essentially the space required for theoperation is whatever the buffer size is that SAVRST* uses. You willprobably also save some time as the transmission and save operationsare occurring more or less in parallel - as one chunk is being saved,another is being sent.

Last but by no means least, it is much easier to monitor for errorsin a CL using the SAVRST* commands - using FTP as you have to scanthe transmission logt afterwards. You could use Scott Klement'sFTPAPI to capture errors in line (and add retry logic if necessary) ,but the work to do this will probably outweigh the effort required toset up any ANYNET link to support using SAVRST*.

When the data arrives on your system is there any kind of spacelimitation at your end ? Can you safely accommodate all the data locally ?

You should consider carefully what the expectation is for this backupdata in terms of a recovery situation. I would be reluctant torecommend this as any kind of reliable backup approach, there arejust way too many things that could go wrong. I don't know how manyobjects are involved, but if there are more than a couple of dozen,then you are going to have quite a backup window going on to save andtransmit the objects; they will all have to be saved at a common timeto be used to restore a whole library for instance. It goes withoutsaying that while you are saving and transmitting the files theapplication will be down. If the save files on your system are meantto be the primary recovery data then I think you have quite an exposure.

That's not to say none of this can work, like anything it can be madeto work and probably work reasonably well with sufficient effort,but it will more than likely require constant monitoring. I like mybackups to be as simple as possible - the simpler they are the morelikely they are to work if I have to perform a recovery. if howeverthis is just a back-stop measure and you are not required to sign offon recovering the system then go for it.


Regards
Evan Harris

At 03:58 a.m. 14/03/2007, you wrote:

Joe/Jerry,

Are you suggesting we backup one library or groups of libraries at a
time and push it to the DR system?

If we're going to write our own backup system I can transfer one SAVF
file using FTP without any additional requirements.

Our desire is to back up to tape piece meal - file by file or lib by lib
using only tape and virtual tape - but it is sounding like this will not
be feasible.

It is beginning to sound like we will have to go by Joe's suggestion of
FTPing save files consisting of groups of files.  This was actually one
of the backup scenarios we were considering, but we were hoping that
vitual tape back up would have been more flexible.

I thank you Joe and Jerry for your suggestions and welcome any
additional comments.

Have a great day!

Adrienne McConnon