Backup Central

On Fri, Jun 04, 2004 at 11:20:06AM -0700, Dege, Robert C. wrote:

It's been over a month, and I'm still having problems with my AIT-2 tape drive (seems like I'm having a lot of amanda problems in general as of late).

As a recap... I could successfully run amdump & have amanda write dumps to tape. But when I tried to restore data from Amanda via "am recover", I would get the following errors:

tar: Skipping to next header
tar: Archive contains obsolescent base-64 headers
tar: A lone zero block at 1639303
tar: Error exit delayed from previous errors
extract_list - child returned non-zero status: 2


I've made more progress & am able to center in on the problem, I just don't know how to resolve it. My problem occurs when I use compression on a backup, and have the backup written to tape. For example:


Backup using Compression Fast with GNUTAR
=========================================
*) Amrecover restoring data from an image in the holding disk - successful
*) Amrecover restoring data from an image written to an AIT-2 tape - fails


Backup using no Compression with GNUTAR
=======================================
*) Amrecover restoring data from an image in the holding disk - successful
*) Amrecover restoring data from an image written to an AIT-2 tape - successful


My current Config:
Amanda - 2.4.4.p1 Tar - 1.13.94 Gzip - 1.3.5

gnutar jumped from 1.13.25 to 1.13.9? in one leap.
Some reported problems with these very recent versions.
I don't recall the nature of the problems, check the archives.
But a build of 1.13.25 would seem a reasonable approach to
see if that is the problem.

--
Jon H. LaBadie jon < at > jgcomp.com
JG Computing
4455 Province Line Road (609) 252-0159
Princeton, NJ 08540-4322 (609) 683-7220 (fax)

gnutar jumped from 1.13.25 to 1.13.9? in one leap.
Some reported problems with these very recent versions.
I don't recall the nature of the problems, check the archives.
But a build of 1.13.25 would seem a reasonable approach to
see if that is the problem.

I was originally having this problem with tar 1.13.25 && gzip 1.3.3. I upgraded both tools to see if it had any affect. When amanda compresses a backup image, does it use gzip or does it use the built in compression that is available in gtar (tar -z)?

-Rob

Dege, Robert C. wrote:
Jon LaBadie wrote:
gnutar jumped from 1.13.25 to 1.13.9? in one leap.

Yup. 1.13.92 had some incompatibility problems, especially
for use with amrecover.
Had a quick look at 1.13.94, and it seems better.
Still more testing needed.


Some reported problems with these very recent versions. I don't
recall the nature of the problems, check the archives. But a build
of 1.13.25 would seem a reasonable approach to see if that is the
problem.


I was originally having this problem with tar 1.13.25 && gzip 1.3.3.
I upgraded both tools to see if it had any affect. When amanda
compresses a backup image, does it use gzip or does it use the built
in compression that is available in gtar (tar -z)?

It uses gzip. AFAIK, "tar -z" is also implemented to pipe the
output through the external program gzip (as is "-j" with bzip2).
Did that change in tar 1.13.94 ?

--
Paul Bijnens, Xplanation Tel +32 16 397.511
Technologielaan 21 bus 2, B-3001 Leuven, BELGIUM Fax +32 16 397.512
http://www.xplanation.com/ email: Paul.Bijnens < at > xplanation.com
***********************************************************************
* I think I've got the hang of it now: exit, ^D, ^C, ^\, ^Z, ^Q, F6, *
* quit, ZZ, :q, :q!, M-Z, ^X^C, logoff, logout, close, bye, /bye, *
* stop, end, F3, ~., ^]c, +++ ATH, disconnect, halt, abort, hangup, *
* PF4, F20, ^X^X, :, KJOB, F14-f-e, F8-e, kill -1 $$, shutdown, *
* kill -9 1, Alt-F4, Ctrl-Alt-Del, AltGr-NumLock, Stop-A, ... *
* ... "Are you sure?" ... YES ... Phew ... I'm out *
***********************************************************************

Dege, Robert C. wrote:

Backup using Compression Fast with GNUTAR
=========================================
*) Amrecover restoring data from an image in the holding disk -
successful
*) Amrecover restoring data from an image written to an AIT-2 tape -
fails

Backup using no Compression with GNUTAR
=======================================
*) Amrecover restoring data from an image in the holding disk -
successful
*) Amrecover restoring data from an image written to an AIT-2 tape -
successful


I would do one more test: create 1 very big file, 1 Gbyte or more,
with garbage, calculate md5sum; and repeat the 4 steps above, each
time checking the md5sum of the restored file.

The reason I suggest this is that single-bit errors (because
bad RAM, or an overheated processor or alpha particles, or the
warranty on the chicken you sacrified has passed...) have immediate
effect on gzip, but go unnoticed many times in other situations.

It sure takes time to test this, but it helps ruling out hardware
problems, with very similar symptoms.


--
Paul Bijnens, Xplanation Tel +32 16 397.511
Technologielaan 21 bus 2, B-3001 Leuven, BELGIUM Fax +32 16 397.512
http://www.xplanation.com/ email: Paul.Bijnens < at > xplanation.com
***********************************************************************
* I think I've got the hang of it now: exit, ^D, ^C, ^\, ^Z, ^Q, F6, *
* quit, ZZ, :q, :q!, M-Z, ^X^C, logoff, logout, close, bye, /bye, *
* stop, end, F3, ~., ^]c, +++ ATH, disconnect, halt, abort, hangup, *
* PF4, F20, ^X^X, :, KJOB, F14-f-e, F8-e, kill -1 $$, shutdown, *
* kill -9 1, Alt-F4, Ctrl-Alt-Del, AltGr-NumLock, Stop-A, ... *
* ... "Are you sure?" ... YES ... Phew ... I'm out *
***********************************************************************

On Friday 04 June 2004 14:54, Dege, Robert C. wrote:
gnutar jumped from 1.13.25 to 1.13.9? in one leap.
Some reported problems with these very recent versions.
I don't recall the nature of the problems, check the archives.
But a build of 1.13.25 would seem a reasonable approach to
see if that is the problem.

I was originally having this problem with tar 1.13.25 && gzip 1.3.3.
I upgraded both tools to see if it had any affect. When amanda
compresses a backup image, does it use gzip or does it use the
built in compression that is available in gtar (tar -z)?

-Rob

tar -z does in fact use gzip to do that compression. gtar may, or may
not be, a link to tar-1.13-25, the recommended version until someone
takes the time to exersize the newer version. gnutar should be the
real thing.

--
Cheers, Gene
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
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Copyright 2004 by Maurice Eugene Heskett, all rights reserved.