On 07/28/2014 09:12 AM, Vladimir Mosgalin wrote:
> Hi ToddAndMargo!
>
>   On 2014.07.27 at 22:25:08 -0700, ToddAndMargo wrote next:
>
>>> Why would you *want* that? Seriously? When backups of files, rather
>>> than filesystems, are much more easily mirrored onto a read-only,
>>> accessible target to allow people to recover their deleted files
>>> quickly and cheaply?
>>>
>>> Even if you need to back up to tape, AMANDA and half a dozen other
>>> technologies do a much better job with "tar" or "rsync" based backups.
>>>
>>
>> Hi Nico,
>>
>> 1) It is *insanely* fast
>>
>> 2) it is command line
>>
>> 3) I am the one that does the recovering, not the user.
>>     (I leave the backup drives unmounted when not on use
>>     on purpose!  I do not want the user anywhere near
>>     those drives.)
>
> "Dump was a stupid program in the first place. Leave it behind."
> "Dump may work fine for you a thousand times. But it _will_ fail under
> the right circumstances. And there is nothing you can do about it."
>
> http://lwn.net/2001/0503/a/lt-dump.php3
>
>
> Seriously, don't use dump. Backup software that highly depends on fs
> implementation is a very bad idea in modern world. Accessing data at low
> level from fs mounted in r/w (i.e. the data might be modified, so
> special tricks are required to extract meaningful copy) is just asking
> for trouble.
>
> Note also that dump is
> 1) highly unportable (in Linux: ext2/3/4 only, *BSD dump isn't
>     compatible with Linux version and so on)
> 2) not supported in other UNIX operating systems anymore because its
>     design doesn't work with modern file system design. dump/restore
>     don't exist in Solaris 11 at all (official recommendation:
>     zfs dump/restore for whole backups, cpio/tar/rdiff-backup/areca/etc
>     for more agile backups). For AIX IBM recommends tar and cpio for
>     file-level backup as modern replacements
>     (http://www.ibmsystemsmag.com/aix/administrator/backuprecovery/Backup-and-Restore-With-AIX)
>
> If are 100% sure that you need fs-level backup instead of file-level
> backup, then don't ask for things impossible by definition (restoring
> fs-level backup to another fs).
>
>
> Yes, dump/restore are fast but they are able to do it by duplicating
> parts of kernel fs implementation in userspace, which is why there will
> be irresistible problems with them.

Hi Vladimir,

   Is xfsdump any better?

   What do you prefer in its place?

   It looks like a full wipe to go to 7 and xfs anyway.

-T