Re: [Bacula-users] restore from fifo - block sizes?

[Kern S. <ke...@si...>]

I wonder if we couldn't require a $10 donation to the project every time
someone forgets to include the Bacula version? I'd probably be a
multi-millionaire by now.  :-)

It looks like you are running some 1.39 version, and any FIFO use for the
Device type is likely to be broken as there is no regression test for it. 
In any case, I cannot imagine any reason to use a FIFO device unless you
have some sort of pseudo attached tape device.  You are probably wasting
your time trying to get it to work, unless there is no other way to do
what you want.

If you are trying to write DVD images, a disk Volume would do quite well.
If you want to write directly to DVD, the current beta seems to be in
pretty good shape.

Regards,

Kern


> I'm trying to use a fifo for backup/restore.
>
> I have the storage set up for min and max block size = 1024.
>
> My runbeforejob script uses dd with ibs=1024 obs=1024 conv=sync, to pull
> the data from the fifo and save it to a file (saving to the file is just
> an interim test setup; I'll do something else with the data later). I
> tried it with and without the conv=sync.
>
> The first few blocks seem fine. However, it always seems to write fewer
> bytes out for the fifth block, resulting in a sixth block that starts at
> the wrong place. This shows up in the log as something like:
>
> Enter dispatch_msg type=4 msg=monica-sd:
> RestoreFiles.2006-10-22_10.40.43 Error: block.c:263 Volume data error at
> 0:6143! Wanted ID: "BB02", got "". Buffer discarded.
>
> This almost feels like a block sync error inside of bacula. If bacula
> was actually outputing a smaller block size, then the conv=sync would
> have taken care of it, so that on restore the beginning of each block
> would at least look right.
>
> Can anyone shed any light on this? Here is my storage definition:
>
> Device {
>   Name = SafeDVD
>   Archive Device = "/tmp/backup_fifo"
>   Device Type = Fifo
>   Media Type = "Safe DVD"
>   Minimum block size = 1024
>   Maximum block size = 1024
>   AlwaysOpen = no
>   LabelMedia = no
>   Automatic Mount = no
>   Random Access = no
>   RequiresMount = no
>   RemovableMedia = no
>   VolumePollInterval = 10
> }
>
> And my scripts for backup and restore runbeforejob:
>
> Here's the one for backup:
>
> #!/bin/bash
> #
>
> # create a fifo
> #
> /bin/rm -f /tmp/backup_fifo
> /bin/mkfifo --mode=777 /tmp/backup_fifo
>
> # start the backup process reading from it
>
> ( nohup dd if=/tmp/backup_fifo of=/var/tmp/mybackup_ \
>  ibs=1024 obs=1024 conv=sync ) &>/dev/null </dev/zero &
>
>
> And here's the one for restore:
>
> #!/bin/bash
> #
>
> # create a fifo
> #
> /bin/rm -f /tmp/backup_fifo
> /bin/mkfifo --mode=777 /tmp/backup_fifo
>
> # start the backup process reading from it
>
> ( nohup dd if=/var/tmp/mybackup_ of=/tmp/backup_fifo \
>    bs=1024 ) &>/tmp/restore.err </dev/zero &
>
>
>