FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > CentOS > CentOS

 
 
LinkBack Thread Tools
 
Old 02-06-2012, 05:44 PM
Les Mikesell
 
Default schily tools

On Mon, Feb 6, 2012 at 12:04 PM, Alan McKay <alan.mckay@gmail.com> wrote:
> Hey folks,
>
> I'm reading up on gtar for tape archiving and it sounds kind of nasty and
> not something I really want to rely on.
>
> It looks like star from the schily tools is preferred. *I'm using Centos
> (and RHEL) 5.7 which seems to have star but not sdd.

I don't think there is any such general consensus. Are you reading
something that favors Solaris/*bsd over GNU based systems?

> Which leads me to believe that the Schily tools are maybe a bit "rogue"

I doubt if they are as well maintained in linux distros as the GNU
tool set, particularly in terms of having recent fixes backported into
the versions carried in enterprise distros.

> My basic requirement with what I'm doing is to use standard tools and
> formats so that archives I write today can be readable in 10 years.

I've never had any doubts that current GNU tar would extract archives
made with it 10+ years ago - in fact I'm fairly sure I've done that.
Or that I'd be able to obtain a copy of it in the future.

> Is the use of Schily tools going to be contrary to my basic requirement?
> Is that considered a risk for future readability?

It shouldn't matter if you don't use either of the version's
extensions, and for archiving you probably don't need them. For
example, star and GNUtar use very different concepts for incremental
backups - star is sort of like dump and must work on filesystem
boundaries where GNUtar's --listed incremental needs a file to hold
state but will work on arbitrary directories and can span mount
points. But for archiving, you probably only care about the maximum
size of a file it can handle.

--
Les Mikesell
lesmikesell@gmail.com
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 02-06-2012, 05:46 PM
Dennis Clarke
 
Default schily tools

> Hey folks,
>
> I'm reading up on gtar for tape archiving and it sounds kind of nasty and
> not something I really want to rely on.
>
> It looks like star from the schily tools is preferred. I'm using Centos
> (and RHEL) 5.7 which seems to have star but not sdd.
>
> Which leads me to believe that the Schily tools are maybe a bit "rogue"
>
> My basic requirement with what I'm doing is to use standard tools and
> formats so that archives I write today can be readable in 10 years.
>
> Is the use of Schily tools going to be contrary to my basic requirement?
> Is that considered a risk for future readability?

Use star like so :

star -c -p -acl -sparse -dump -fs=32m -fifostats -time
-C /some_dir dir1 dir2 dir3 file=/dev/rmt/0mbn

or something like that will work like a charm and be POSIX spec compliant.
That means you can still read it in 20 years .. if the tape survives.

dc


--
--
http://pgp.mit.edu:11371/pks/lookup?op=vindex&search=0x1D936C72FA35B44B
+-------------------------+-----------------------------------+
| Dennis Clarke | Solaris and Linux and Open Source |
| dclarke@blastwave.org | Respect for open standards. |
+-------------------------+-----------------------------------+

_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 02-06-2012, 05:48 PM
Dennis Clarke
 
Default schily tools

> I doubt if they are as well maintained in linux distros as the GNU
> tool set, particularly in terms of having recent fixes backported into
> the versions carried in enterprise distros.

They are updated pretty much every month.

>> My basic requirement with what I'm doing is to use standard tools and
>> formats so that archives I write today can be readable in 10 years.
>
> I've never had any doubts that current GNU tar would extract archives
> made with it 10+ years ago - in fact I'm fairly sure I've done that.
> Or that I'd be able to obtain a copy of it in the future.

GNU tar .. has its own bugs. Is it really standards compliant?

>> Is the use of Schily tools going to be contrary to my basic requirement?
>> Is that considered a risk for future readability?
>
> It shouldn't matter if you don't use either of the version's
> extensions, and for archiving you probably don't need them. For
> example, star and GNUtar use very different concepts for incremental
> backups - star is sort of like dump and must work on filesystem
> boundaries where GNUtar's --listed incremental needs a file to hold
> state but will work on arbitrary directories and can span mount
> points.

same sort of deal with star .. but you should go ask the author.

dc


--
--
http://pgp.mit.edu:11371/pks/lookup?op=vindex&search=0x1D936C72FA35B44B
+-------------------------+-----------------------------------+
| Dennis Clarke | Solaris and Linux and Open Source |
| dclarke@blastwave.org | Respect for open standards. |
+-------------------------+-----------------------------------+

_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 02-06-2012, 05:58 PM
Alan McKay
 
Default schily tools

> Are you reading
> something that favors Solaris/*bsd over GNU based systems?

No, why, are the Schily tools standard over there?



> I've never had any doubts that current GNU tar would extract archives
> made with it 10+ years ago - in fact I'm fairly sure I've done that.
> Or that I'd be able to obtain a copy of it in the future.


Yeah, that is the plus side. But it seems gtar is rather abysmal at
recovering from errors in archives so if there is ever a problem, you're
cooked.

Is there any truth to that?

--
“Don't eat anything you've ever seen advertised on TV”
- Michael Pollan, author of "In Defense of Food"
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 02-06-2012, 06:16 PM
Les Mikesell
 
Default schily tools

On Mon, Feb 6, 2012 at 12:48 PM, Dennis Clarke <dclarke@blastwave.org> wrote:
>
>> I doubt if they are as well maintained in linux distros as the GNU
>> tool set, particularly in terms of having recent fixes backported into
>> the versions carried in enterprise distros.
>
> They are updated pretty much every month.

My experience is very old (probably w/CentOS 3.x), but when I found
problems with star they were fixed in its own source but I gave up
before the packaged version was updated. Maybe that has changed...

>>> My basic requirement with what I'm doing is to use standard tools and
>>> formats so that archives I write today can be readable in 10 years.
>>
>> I've never had any doubts that current GNU tar would extract archives
>> made with it 10+ years ago - in fact I'm fairly sure I've done that.
>> Or that I'd be able to obtain a copy of it in the future.
>
> *GNU tar .. has its own bugs. Is it really standards compliant?

Everything has had bugs. Have you reported the bugs, and were the
reports ignored? As for standards, GNU tar is the default tar
shipped on most or all linux distributions so it is almost guaranteed
to be the most prevalent. The historical limits on sizes of files and
paths by the posix standards and the fact that tar predates them have
kind of made a mess of standards, and you probably don't want to be
restricted by them. Better to plan on being able to get a copy of the
version you write with onto any future platform. I compiled GNUtar on
DOS eons ago and wouldn't expect anything more hostile in the future.

--
Les Mikesell
lesmikesell@gmail.com
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 02-06-2012, 06:24 PM
Les Mikesell
 
Default schily tools

On Mon, Feb 6, 2012 at 12:58 PM, Alan McKay <alan.mckay@gmail.com> wrote:
>> Are you reading
>> something that favors Solaris/*bsd over GNU based systems?
>
> No, why, are the Schily tools standard over there?

Not necessarily - just that GNUtar is not ubiquitous and there might
be more concern about strict UStar format compliance.

>> I've never had any doubts that current GNU tar would extract archives
>> made with it 10+ years ago - in fact I'm fairly sure I've done that.
>> Or that I'd be able to obtain a copy of it in the future.
>
>
> Yeah, that is the plus side. *But it seems gtar is rather abysmal at
> recovering from errors in archives so if there is ever a problem, you're
> cooked.
>
> Is there any truth to that?

I don't think so - I'm fairly sure I've seen GNUtar complain about bad
headers, say 'skipping to next header' and then find something. It
won't do that if you used the -z option because you generally can't
recover from errors in compression. But, I've never seen a tape drive
recover from an error and continue past it anyway so in practice
that's not going to matter. If you are concerned about errors, keep
more copies.

--
Les Mikesell
lesmikesell@gmail.com
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 02-06-2012, 08:04 PM
Alan McKay
 
Default schily tools

>
> I don't think so - I'm fairly sure I've seen GNUtar complain about bad
> headers, say 'skipping to next header' and then find something. It
> won't do that if you used the -z option because you generally can't
> recover from errors in compression
>
>
Bam! As an aside to my current line of questioning, I was looking for an
excuse not to compress and you just gave it to me! Yay!

Compressing makes it nigh impossible to know whether or not the data will
fit on the tape without doing a test compress ahead of time, which can take
several hours depending on the amount of data.



--
“Don't eat anything you've ever seen advertised on TV”
- Michael Pollan, author of "In Defense of Food"
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 02-06-2012, 08:21 PM
Les Mikesell
 
Default schily tools

On Mon, Feb 6, 2012 at 3:04 PM, Alan McKay <alan.mckay@gmail.com> wrote:
>>
> Compressing makes it nigh impossible to know whether or not the data will
> fit on the tape without doing a test compress ahead of time, which can take
> several hours depending on the amount of data.

Tape drives generally have their own compression options that you can
change with the mt command. Their speed can also vary wildly depending
on the block size you use and whether you can supply the data fast
enough to keep them streaming.

--
Les Mikesell
lesmikesell@gmail.com
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 02-06-2012, 08:56 PM
Dennis Clarke
 
Default schily tools

> On Mon, Feb 6, 2012 at 12:48 PM, Dennis Clarke <dclarke@blastwave.org> wrote:
>>
>>> I doubt if they are as well maintained in linux distros as the GNU
>>> tool set, particularly in terms of having recent fixes backported into
>>> the versions carried in enterprise distros.
>>
>> They are updated pretty much every month.
>
> My experience is very old (probably w/CentOS 3.x), but when I found
> problems with star they were fixed in its own source but I gave up
> before the packaged version was updated. Maybe that has changed...

It is pretty up to date :

ftp://ftp.berlios.de/pub/schily/AN-2012-01-23

Course that includes a pack of goodies. Like a real cdrecord that really
works with blue ray etc etc.

dc

--
--
http://pgp.mit.edu:11371/pks/lookup?op=vindex&search=0x1D936C72FA35B44B
+-------------------------+-----------------------------------+
| Dennis Clarke | Solaris and Linux and Open Source |
| dclarke@blastwave.org | Respect for open standards. |
+-------------------------+-----------------------------------+

_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 02-06-2012, 10:48 PM
Keith Keller
 
Default schily tools

On 2012-02-06, Alan McKay <alan.mckay@gmail.com> wrote:
>
> Bam! As an aside to my current line of questioning, I was looking for an
> excuse not to compress and you just gave it to me! Yay!

afio is an archiver (available from third-party repos, not base) which
can compress yet still recover--it basically compresses each file
individually instead of compressing the entire archive, so the file
might be unrecoverable but the rest of the archive is still intact.
I use it for my tape backups (though your point of not knowing if
it'll fit on the tape is valid).

--keith


--
kkeller@wombat.san-francisco.ca.us


_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 

Thread Tools




All times are GMT. The time now is 04:01 PM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright 2007 - 2008, www.linux-archive.org