Several of you are talking about 'expiring a file on the tape.' This has to be a BRMS or other tape-management-system function, and only affects the BRMS-maintained database of what's on which tape!
Once a tape is written, the OS has no way (AFAIK) to flag a single file in the middle of the tape as 'expired.' The only thing you could do is write another file starting at that sequence on the tape, effectively deleting everything from that point to the end-of-tape.
There used to be a utility on the S/3 that let you play with the tape-- If a tape had been initialized without clearing the tape you could read past the end-of-tape marker (INZTAP just writes a new header on the tape with an end-of-tape mark just after the header) and explore the files that are still there. Except for the 1st file on the tape, you could retrieve the files from the tape! You still couldn't update a file in the middle of a tape.
I'm afraid, Rob, you're SOL as far as deleting all past backups from existing backup tapes.
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Even if you could drop off one person's email, you still have a problem-- there'd still be a copy of all that person's email in the email of the person they sent the message to or received the message from.
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Now-- if you're using LTO-5 (or higher) tape drives, LTO does support the Linear Tape File System. From Wikipedia (
https://en.wikipedia.org/wiki/Linear_Tape-Open):
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"Linear Tape File System
"The Linear Tape File System (LTFS) is a self-describing tape format and file system made possible by the partition feature. File data and filesystem metadata are stored in separate partitions on the tape. The metadata, which uses a standard XML schema, is readable by any LTFS-aware system and can be modified separately from the data it describes. The Linear Tape File System Technical Work Group of the Storage Networking Industry Association (SNIA) works on the development of the format for LTFS.[50]
"Without LTFS, data is generally written to tape as a sequence of nameless "files", or data blocks, separated by "filemarks". Each file is typically an archive of data organized using some variation of tar format or proprietary container formats developed for and used by backup programs. In contrast, LTFS utilizes an XML-based index file to present the copied files as if organized into directories. This means LTFS-formatted tape media can be used similarly to other removable media (USB flash drive, external hard disk drive, and so on).
"While LTFS can make a tape appear to behave like a disk, it does not change the fundamentally sequential nature of tape. Files are always appended to the end of the tape. If a file is modified and overwritten or removed from the volume, the associated tape blocks used are not freed up: they are simply marked as unavailable, and the used volume capacity is not recovered. Data is deleted and capacity recovered only if the whole tape is reformatted.[citation needed] [[and I don't know if it's possible to read past the 'unavailable' flag and retrieve the data marked as unavailable --PEM]]
"In spite of these disadvantages, there are several use cases where LTFS-formatted tape is superior to disk and other data storage technologies. While LTO seek times can range from 10 to 100 seconds, the streaming data transfer rate can match or exceed disk data transfer rates. Additionally, LTO cartridges are easily transportable and the latest generation can hold more data than other removable data storage formats. The ability to copy a large file or a large selection of files (up to 1.5 TB for LTO-5 or 2.5 TB for LTO-6) to an LTFS-formatted tape, allows easy exchange of data to a collaborator or saving of an archival copy.
"Since LTFS is an open standard, LTFS-formatted tapes are usable by a wide variety of computing systems."
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The full article on the LTFS (
https://en.wikipedia.org/wiki/Linear_Tape_File_System) lists the systems and drives that support this format. Unfortunately, most are Linux-, Mac-, or Windows-type OSs, and the drives appear to be LTO-5 or better.
Paul E Musselman
PaulMmn@xxxxxxxxxxxxx
-----Original Message-----
From: MIDRANGE-L <midrange-l-bounces@xxxxxxxxxxxx> On Behalf Of Rob Berendt
Sent: Thursday, September 20, 2018 8:46 AM
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Subject: RE: Purging an IFS stream file from backups
<snip>
Do the auditors know that you're planning to delete a file from all past
backups? (;
</snip>
Exactly why I want to erase it from all past backups. Picture this: You
have someone's Domino mail file. Let's say ssnead.nsf. He has left your
company. He has been gone for a set number of days. Standard company
policy is to then remove his mail file completely. With no trace of it
around. No way to resurrect it if some legal battle ensues. Hey, if
you're following a standard policy and not trying to thwart a particular
case...
My thought is that if I just expire it on the tape I can still restore it
until it's written over. Not acceptable.
Normally when you do an IFS save sequence ### may contain files from
multiple directories and subdirectories. So I'd really rather not delete
that particular sequence number and lose the backups from all those other
files.
DUPMEDBRM doesn't allow you to omit one particular file from within that
sequence.
Only ways I can think of is:
1) Restore that directory, delete the file. Save it again. Con:
expiration date is altered to the new date, unless I override that. And
if I restore/save from a different system and/or directory it's harder to
do WRKLNKBRM and find some other object I do want to restore it.
2) DUPMEDBRM and omit that sequence. Con: Loss of the backup of the
rest of the files.
3) INZMEDBRM and wipe the tape. Con: Loss of the backup of the rest of
the files. Plus other stuff on that tape.
Just to complicate matters, we use parallel saves.
Rob Berendt
--
IBM Certified System Administrator - IBM i 6.1
Group Dekko
Dept 1600
Mail to: 2505 Dekko Drive
Garrett, IN 46738
Ship to: Dock 108
6928N 400E
Kendallville, IN 46755
http://www.dekko.com
From: "Musselman, Paul" <pmusselman@xxxxxxxxxxxxxxxx<mailto:pmusselman@xxxxxxxxxxxxxxxx>>
To: "Midrange Systems Technical Discussion" <midrange-l@xxxxxxxxxxxx<mailto:midrange-l@xxxxxxxxxxxx>>
Date: 09/19/2018 05:02 PM
Subject: RE: Purging an IFS stream file from backups
Sent by: "MIDRANGE-L" <midrange-l-bounces@xxxxxxxxxxxx<mailto:midrange-l-bounces@xxxxxxxxxxxx>>
Once the object is saved on tape there's little need to delete the file
from the tape-- the system resources have already been spent saving the
object. You'd be better off not saving the object again.
As far as duplicating a tape and removing 1 stream file from it, I don't
know of any simple way to do it. Although you can display a tape and see
all of the individual objects saved, I don't think there's an 'omit IFS
file' parameter on the dup tape commands.
Do the auditors know that you're planning to delete a file from all past
backups? (;
Paul E Musselman
PaulMmn@xxxxxxxxxxxxx<mailto:PaulMmn@xxxxxxxxxxxxx>
-----Original Message-----
From: MIDRANGE-L <midrange-l-bounces@xxxxxxxxxxxx<mailto:midrange-l-bounces@xxxxxxxxxxxx>> On Behalf Of Rob
Berendt
Sent: Wednesday, September 19, 2018 4:31 PM
To: midrange-l@xxxxxxxxxxxx<mailto:midrange-l@xxxxxxxxxxxx>
Subject: Purging an IFS stream file from backups
Given that we do all saves using BRMS is there a way to purge a file from
all backups?
First, I'm not happy that I cannot seem to be able to go directly with
WRKLNKBRM DIR('/home/ROB/aatest2.txt')
But instead I have to do
WRKLNKBRM DIR('home')
and drill down to it.
That being said I can eventually find that file, and all media it is saved
on. However I want to remove that file from all media it is saved on. I
see that BRMS has a remove option but I am suspecting that it simply
removes that file from the BRMS data but leaves it on tape, correct?
Also IBM i Access Client Solutions doesn't seem to have any BRMS plug ins,
correct?
Tried IBM Navigator for i (aka
http://youribmi:2001) but the BRMS stuff in
there didn't seem to have any function like WRKLNKBRM.
Failing any cool way to do this, and supposing that the BRMS remove option
just removes it from BRMS data and not the tape, is there some way to
delete just one file from a sequence number on a save outside of BRMS?
For example, a SAV command saves all IFS data to one sequence on a volume.
How would I delete just '/home/ROB/aatest2.txt' from that?
Rob Berendt
--
IBM Certified System Administrator - IBM i 6.1
Group Dekko
Dept 1600
Mail to: 2505 Dekko Drive
Garrett, IN 46738
Ship to: Dock 108
6928N 400E
Kendallville, IN 46755
http://www.dekko.com
midrange.com
