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Home > Archive > Backup Software > May 2004 > Catching deletions
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Catching deletions
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| We all know a Full backup does everything and either an Incremental or
Differential does the files after the last Full, but the trouble is that
files deleted on the system after the last Full backup are still on the tape
such that when you restore the files, you get what you want back plus what
you don't. Are there any tips or particular software packages, other than
running a full backup everyday, to avoiding this problem?
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| "ITMA" <mindyourownbusiness@123.com> wrote in message
news:4069ccff$1_3@mk-nntp-1.news.uk.worldonline.com...
> We all know a Full backup does everything and either an Incremental or
> Differential does the files after the last Full, but the trouble is that
> files deleted on the system after the last Full backup are still on the
tape
> such that when you restore the files, you get what you want back plus what
> you don't. Are there any tips or particular software packages, other than
> running a full backup everyday, to avoiding this problem?
>
Yes, this is the most disgrace in backup world. The only file-based backup
software that saves correct partition state (also deleted files - it just
saves list of all files that exist in fixed moment) is Dantz Retrospect.
With it you can restore partition without deleted files.
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| Johnny Oestergaard 2004-05-23, 12:14 pm |
| Depending on your needs Veritas Netbackup has support for this. (and
any other enterprise backup software)
/johnny
On Tue, 30 Mar 2004 20:39:43 +0100, "ITMA"
<mindyourownbusiness@123.com> wrote:
>We all know a Full backup does everything and either an Incremental or
>Differential does the files after the last Full, but the trouble is that
>files deleted on the system after the last Full backup are still on the tape
>such that when you restore the files, you get what you want back plus what
>you don't. Are there any tips or particular software packages, other than
>running a full backup everyday, to avoiding this problem?
>
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| > The only file-based backup software that saves correct partition
> state (also deleted files - it just saves list of all files that exist in
> fixed moment) is Dantz Retrospect.
Downloaded a demo version and it looks leagues better than anything I've
seen. A bit annoying that two or three options seem to be, well ....,
optionall as in extra cost even once you've bought the basic package but all
other software I've seen seems in the stone age compared to this.
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| "Johnny Oestergaard" <joe@joe.net> wrote in message
news:8p0p60la1c4b1edbfk2tavgmb9fmnu9seb@
4ax.com...
> Depending on your needs Veritas Netbackup has support for this. (and
> any other enterprise backup software)
>
Who are you and what you are talking about? I was specially consulting this
topic with Veritas
tech-support and they sayd me very clearly that Veritas software don't
support this feature.
Of course I have readed also lots of manuals - only Retrospect support this
(snapshots in Dantz
term)
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| Johnny Oestergaard 2004-05-23, 12:14 pm |
| If I remember right the feature is called something like "true image
restore" or something like that. It is a per-policy setting.
If you look in this manual
http://ftp.support.veritas.com/pub/...rver/264235.pdf
on page 96 there is a little about it.
We don't use it because all our backups are full backups, but as I
know it it should work without any problem.
And I am just one of many Netbackup users.
/johnny
On Fri, 2 Apr 2004 08:26:50 +0300, "Tron" <puudub> wrote:
>"Johnny Oestergaard" <joe@joe.net> wrote in message
> news:8p0p60la1c4b1edbfk2tavgmb9fmnu9seb@
4ax.com...
>
>Who are you and what you are talking about? I was specially consulting this
>topic with Veritas
>tech-support and they sayd me very clearly that Veritas software don't
>support this feature.
>Of course I have readed also lots of manuals - only Retrospect support this
>(snapshots in Dantz
>term)
>
| |
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| "Johnny Oestergaard" <joe@joe.net> wrote in message
news:omnb709b5p6lmv9dj8jqg06n0keknkq7v7@
4ax.com...
> If I remember right the feature is called something like "true image
> restore" or something like that. It is a per-policy setting.
>
> If you look in this manual
>
http://ftp.support.veritas.com/pub/...rver/264235.pdf
> on page 96 there is a little about it.
>
> We don't use it because all our backups are full backups, but as I
> know it it should work without any problem.
>
Sorry, I was meant BackupExec. Yes, you right, I was little wrongly
informed.
But in this document I was find out this:
-------8<-------------------------
? A true-image restore preserves files that are currently in the directory
but were not
present when the backup was done. In our previous example, assume you
created a
file named file5 after the incremental backup occurred on 12/04/2003, but
before
doing the restore. In this case, the contents of the directory after the
restore is:
file1
file2
file4
file5
-------8<-------------------------
-------8<-------------------------
This means that "true-image restore" isn't 100% TRUE !
If you want to restore exact point-in-time disk layout, then you must first
delete all disk
content and then restore every file. This is time-consuming compared with
Retrospect, that
don't need to clear disk content. It leaves unchanged files alone and
deletes unneeded files.
Tron.
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| Johnny Oestergaard 2004-05-23, 12:14 pm |
| As I read it, it's like this.
Like any other logical restore it will never delete any files (except
the files the restore replaces. The restore can't know if the file was
created again with the same name.
You have
Day 1: (Full backup)
File 1
File 2
File 3
Day 2: (incremental)
File 1 (no change / no backup)
File 2 (changed / backed up)
File 3 (deleted / no backup)
Day 3: (incremental)
File 1 (no change / no backup)
File 2 (no change / no backup)
File 4 (changed / backed up)
Then you loose you diskdrive and makes a restore without "True Image
Restore" and you end up with:
File 1
File 2
File 3
File 4
Same restore, but with "True Image Restore"
File 1
File 2
File 4
If you need to be able to go back to a specific "point in time" of the
total diskdrive I would not use this kind of backup at all, but "snap
shot" backups (also supported under NetBackup)
When we talk about most servers you realy don't want to restore "snap
shot" backups, so what most installations do is to use "Snap shot"
backups letting your SAN do the Snap-Shot of the volume and the let
your backup software back the "snap shot" volume up to tape, but in
the backupsoftware it still looks as if the backup was taken directly
from the original diskvolume so file restores look the same as they
always did.
By the way the only thing BackupExec and NetBackup has in common is
that they are owned by Veritas and they both are backupsoftware.
They are not even sold and supported by the same part of the
organisation at Veritas.
NetBackup is the most used backup software in the world (except in the
mainframe world since it doesn't support mainframes)
It supports so many platforms, scale very good and can be used in big
installations.
/johnny
On Fri, 9 Apr 2004 14:15:34 +0300, "Tron" <puudub> wrote:
>"Johnny Oestergaard" <joe@joe.net> wrote in message
> news:omnb709b5p6lmv9dj8jqg06n0keknkq7v7@
4ax.com...
>http://ftp.support.veritas.com/pub/...rver/264235.pdf
>
>
>Sorry, I was meant BackupExec. Yes, you right, I was little wrongly
>informed.
>But in this document I was find out this:
>
>-------8<-------------------------
>? A true-image restore preserves files that are currently in the directory
>but were not
>present when the backup was done. In our previous example, assume you
>created a
>file named file5 after the incremental backup occurred on 12/04/2003, but
>before
>doing the restore. In this case, the contents of the directory after the
>restore is:
>file1
>file2
>file4
>file5
>-------8<-------------------------
>-------8<-------------------------
>
>This means that "true-image restore" isn't 100% TRUE !
>If you want to restore exact point-in-time disk layout, then you must first
>delete all disk
>content and then restore every file. This is time-consuming compared with
>Retrospect, that
>don't need to clear disk content. It leaves unchanged files alone and
>deletes unneeded files.
>
>Tron.
>
>
>
>
>
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| "Johnny Oestergaard" <joe@joe.net> wrote in message
news:n2ed70phrs4jbjjnfl5o7lomdo7ruc4tco@
4ax.com...
>
> Like any other logical restore it will never delete any files (except
> the files the restore replaces.
Retrospect deletes all files those don't exist in snapshort session.
>The restore can't know if the file was
> created again with the same name.
Yes it can - Retrospect "match rule" compares windows files with
name,size,creation date and
modified date. If anything is different, then file don't match. Very good
strategy, better than
untrustable "archive attribute bit" or even worse "newer file".
> If you need to be able to go back to a specific "point in time" of the
> total diskdrive I would not use this kind of backup at all,
Why not? What kind you prefer? The only problem may be correct "system
state"
restoration, but Retrospect is good enough.
> When we talk about most servers you realy don't want to restore "snap
> shot" backups,
I think term "server" haven't nothing to do with backups. Backup means
backing up
operating system or database. In any cases files to be in harmony is very
important.
If after restore partition contains unneeded files (created after last
backup), then in most
cases this isn't dangerous but simple litter your media. But
enterprise-level backup isn't good
only for servers, it's just good software and nothing more. Client-server
and messaging-system additions can completely ignore example in home
machine.
Tron.
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| > > If you need to be able to go back to a specific "point in time" of the[vbcol=seagreen]
Retrospect claims to do this yet so far as I can see from using their demo
version you can only, in one easy move, restore to the latest "point in
time", including the non-reinstating of deleted files. To restore earlier
versions of files it seems you have to do them manually. I cannot, for
instance, work out how to restore everything to, for example, the back up
before last.
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| "Johnny Oestergaard" <joe@joe.net> wrote in message
news:mqlh709sfktfe69581j027gmqobi1cicl8@
4ax.com...
> From all the years I have been in some kind of computer operations I
> have never had to be able to restore any diskvolumes on file servers
> to a "point-in-time" state.
> Restore of volume after I lost a diskvolume I have done a lot of times
> (especialy in the "old" days before raid systems)
> I have done a lot of "point-in-time" restores, but that has always
> been some kind of database systems or applicationbackups (and in this
> kind of cases files are normaly never deleted, just updated)
You talk about databases backup - this is completely different from
operating system backup.
As any server contain both operating-system and databases, then you can't
backup them together. Operating-system requires exact "point-in-time"
restore (open-file backup), but database backup depends completely from this
database and it's support API to backup software. Some databases allow new
files just exist alone, but some databases require content-indexed
repository and if indexes don't exist, then also file don't exist for user
or in worse situation database crashes at all.
Retrospect example gives you choice while restoration:
a) restore entire volume (deletes all files those don't exist in snapshot -
good for OS restore)
b) replace corresponding files (leave later added files alone - good for
databases)
p.s. Fact that Veritas soft was very widely in use while previous days don't
tell nothing - widely
used things aren't in most cases good things and also server administrators
aren't experts in many
situations. Experts are programmers but not server administrators who choose
crapy backup software for corporation and give good money for that business.
I don't like Veritas soft, because its too stagnation crap. It compares
files only based on archive
bit. But example most ini or configuration files changed completely without
changing this bit.
This stategy is crap anyway.
Tron.
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| On Tue, 30 Mar 2004 20:39:43 +0100, "ITMA"
<mindyourownbusiness@123.com> wrote:
>We all know a Full backup does everything and either an Incremental or
>Differential does the files after the last Full, but the trouble is that
>files deleted on the system after the last Full backup are still on the tape
>such that when you restore the files, you get what you want back plus what
>you don't. Are there any tips or particular software packages, other than
>running a full backup everyday, to avoiding this problem?
>
Legato Networker allows "point in time" recovery.
Phil
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