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Conference decwet::networker

Title:NetWorker
Notice:kits - 12-14, problem reporting - 41.*, basics 1-100
Moderator:DECWET::RANDALL.com::lenox
Created:Thu Oct 10 1996
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:750
Total number of notes:3361

379.0. "4.2a and zero length files?" by STKHLM::BEETS () Tue Feb 04 1997 07:35

Hi

One of my customer have problem recovering old indexes from tape giving zero
length files. This is a known problem when recovering tapes created with NSR 3.0
and recovered under NSR 3.1 and 3.1a(see note 1779). They have upgraded  NSR
from 3.0 to 4.2a without stopping at any version in between.

They use "scanner -s SSID | uasm -rv -m /dir" to build new index from tapes
created under 3.0. Everything seems ok, it takes some time as it should but all
files have zero length after recover.

UNIX version is 3.2D and no NSR patches for 4.2a applied.


From NSR-patch.readme

Steps to install patch nsrv31a-002

Summary:
  Attempting to recover AdvFS files saved by NSR V3.0 or earlier resulted in
  zero length files, and possibly seeing the error message "Too Many Open
  Files". This fixes PTT_DECNSR NSR-162.

Description:
============
  NSR Client binaries trying to receive data streams that were saved using
   NSR V3.0, or earlier, were out-of-phase with the bytes used to recover the
   AdvFS attributes for a file. This caused AdvFS to return an error to NSR
   (properly), which then caused NSR to ignore the remainder of the data stream
   for that file and not close the file. Thus, files were created, left
   open, without attributes or data. This resulted in users seeing files
   that had names, were zero-length, and possibly seeing the error message
   "Too Many Open Files".
  An important note: NSR V3.1 (or later) client binaries recovering data
   from V3.1 (or later) saves work properly, and NSR V3.0 client binaries
   recovering data from V3.0 (or earlier) saves work properly. This only
   affected AdvFS files saved by NSR V3.0 (or earlier) and recovered by
   NSR V3.1 (or later).

  This patch is fixed in the next release (v3.2) of NSR. Only
  apply this patch to NSR v3.1A.

  This patch consists of the following executables:

        recover
        srecover
        nwrecover
        nwretrieve

-----------------------------------------------------------------------------

Is this patch applied for NSR 4.2a?

Is there any workaround?

Is there any incompatibilities between indexes created with 3.0 and how 4.2a
recreates them?



Regards

Gunnar Beets
CSC Sweden
T.RTitleUserPersonal
Name
DateLines
379.1suggestion. go to V4.2BDECWET::EVANSBe a Point Of Light!Tue Feb 04 1997 14:3914
Is this patch applied for NSR 4.2a?

>>>> yes.

Is there any workaround?

>>>> upgrade to V4.2B

Is there any incompatibilities between indexes created with 3.0 and how 4.2a
recreates them?

>>>> no, but an index conversion (one-way) takes place between V3.x and
>>>> V4.x, and there is a KNOWN BUG in V4.2A affecting idnexes, fixed in V4.2B
>>>> save yourself some headcahes, and upgrade now.
379.2tapes created by 4.2a give the same problemSTKHLM::BEETSWed Feb 05 1997 05:3710
Thanks for your reply,


We will upgrade to 4.2b. We got the same problem with tapes created with 4.2a,
then client was deleted, added client again and then used scanner to recreate
the index.



Gunnar
379.3dang -- wish I'd done better researchDECWET::EVANSBe a Point Of Light!Wed Feb 05 1997 12:5219
I thought I was too busy... now I'm paying the price.

 I went throught the code in NSR V3.x (we called it MAGPIE) and found the
 patch I developed for this problem - it turns out, there are no comments,
 but I recall it needed to be done because the buffer being used
 got zeroed after calling AdvFS API to set the file attributes, and then it
 tried to use that same buffer again for inheritable directory attributes.
 Sadly, at that point, it was zero'ed, so gave an error, and the file recover
 stream is swallowed leaving a file header with no data - a zero length file.

   This code is not in V4.2x (a or b), nor is it in V.future - I will alert
 the folks that make patches, and go about insuring this gets into V.future

 stay tuned to the patch topic.  Please thank your customer for upgrading to
 V4.2B!!

 I sincerely apologize for any inconvenience my previous note may have caused.

Bruce Evans
379.4that's why...... :->STKHLM::BEETSFri Feb 07 1997 09:5615
Bruce,


Well, my customer upgraded to 4.2b and of course he still had problem. :-)

All clients created under 4.2x works fine. Only clients from 3.0 have this
problem. It makes sense.

I will stay tuned on patch topic for a patch. I suppose there's no need for any
QAR or IPMT then.


Thanks

Gunnar Beets
379.5early next week, we'll have the patch ready for youDECWET::EVANSBe a Point Of Light!Fri Feb 07 1997 20:017
I've just finally been able to apply the fix to the source tree
 and checked it out to my limits.

We'll need your customer to see if it really fixes it when they
 apply the patch, and do the recover.

Bruce
379.6I'll wait.......STKHLM::BEETSMon Feb 10 1997 05:395
Update this note or send a mail where I can get the patch. I will be away on
Thursday(13th) and Friday(14th).


Gunnar
379.7DECWET::RANDALLThu Feb 20 1997 19:083
The patch is now available.  See Notes 53.12 and 53.13.

-- Rich Randall
379.8Still getting zero byte files with Patch12OTOOA::kap901.kao.dec.com::trimbleMon Apr 07 1997 17:0410
I installed the patch12 on my DUnix 4.0 client that was running 3.2A 
and it still recovered the files as zero bytes...

Talk about frustrating, downloading a 22 Meg TAR to patch a couple of files... 
And it still doesn't work.

Regards,

Jason

379.9DECWET::RANDALLTue Apr 08 1997 18:377
Hi,

Were the clients who are having the problem running V4.0 or later versions
of DIGITAL UNIX while they were running V3.0 of Networker?

-- Rich Randall
379.10Here's the scoopOTOOA::kap901.kao.dec.com::trimbleWed Apr 09 1997 17:1018
Here is the situation:

NT 3.51 Alpha 2100A server running 4.3 of Networker
Alpha 2100A running OSF 3.2C and Networker client 3.2B

The OSF system was upgraded to 4.0 and I tried doing a
restore using the 3.2B NSR client.  Zero block files.
Upgraded to 4.2B of client and tried restore. Zero byte
files.
Applied latest patch (12) and tried restore.  Zero byte
files.

Any patches needed for DUnix 4.0?

Thanks,

Jason

379.11DECWET::FARLEEInsufficient Virtual um...er....Wed Apr 09 1997 18:379
I'm afraid that the bad news is that if the backups were done using
DU 4.0 or above, with a version of NetWorker prior to 3.2A  of NetWorker,
the data is simply not on tape correctly.

Your best bet is to try to restore a backup which was taken before
the upgrade to DU4.0 , using the 3.2B (or better yet, 4.2B) NetWorker client
software.

Kevin
379.12Not good...OTOOA::kap901.kao.dec.com::trimbleThu Apr 10 1997 09:484
You've got to be kidding me...  This is not good.

Jason

379.13this is FAR too serious to be kidding anyone, Jason.DECWET::EVANSNSR EngineeringFri Apr 11 1997 18:3810
Believe me... we understand what is happening in your mind right now.
  we've gone through it.

Do the right thing, and get the data backed up and CHECK IT so you can
 sleep easy. Do random browses, and check sizes of files in the GUI.
 Also, do random recovers (using relocate), and sum/diff/whatever the
 saved file with the recovered-relocated file.

Do this for UFS, AdvFS, and (if there) raw partitions. Be aggressive, not
 passive, in your data protection mechanisms.
379.14Time is a scarce OTOOA::kap901.kao.dec.com::trimbleTue Apr 15 1997 09:4814
Thanks for the tips.  Unfortunately I am not a full time backup person.  I
installed it, but I don't have the time to go into these details all the time.
It would take a person full time to check all of the systems we have
backing up to Networker now.  We can't afford that kind of resource.  Maybe
in the future this will change.  Right now I have upgraded the system and
done full backups and tried a restore of one file to make sure it restored
fine and it did.  So I am resting a bit easier now (as is the customer).

I have other problems now which require a new note.

Regards,

Jason