[Bacula-users] Bacula Windows 3.0.1 and DLT-V4 DLTtape VS 160-320 GB - compression problem

[Toto Rototo]

Hi.

I have installed Bacula Win 3.0.1 under Windows XP without problems.

When i make a folder backup (size 190 Go on my hard disk), Bacula ask for a second tape (tape one is full with 190,806,491,136 VolBytes).

DltSage utility report : compression is on and 335 Gb are used.

I have tried with "Minimum Block Size = 32768 Maximum Block Size = 32768", the problem is the same.

My DLT-V4 has the latest firmware (v10) and the latests windows drivers (4.3.33).

Can someone help me ?

Thanks.

[John Drescher]

Post by Toto Rototo
I have installed Bacula Win 3.0.1 under Windows XP without problems.
When i make a folder backup (size 190 Go on my hard disk), Bacula ask for a
second tape (tape one is full with 190,806,491,136 VolBytes).
DltSage utility report : compression is on and 335 Gb are used.
I have tried with "Minimum Block Size = 32768 Maximum Block Size = 32768",
the problem is the same.
My DLT-V4 has the latest firmware (v10) and the latests windows drivers (4.3.33).
Can someone help me ?

That looks perfectly fine to me. I mean 190 GB is greater 160GB. You
do realize that compression depends on the files you back up and if
some of them are already compressed (.zip, .jpg ...) you will not get
close to the often highly optimistic compression rate that
manufacturers state. I expect 1.5:1 on average for drives that state
2:1.

John

[John Drescher]

Post by Toto Rototo
I have tried with "Minimum Block Size = 32768 Maximum Block Size = 32768",
the problem is the same.

I would not mess with the block size especially to make it smaller than default.

John

[John Drescher]

Post by John Drescher

Post by Toto Rototo
I have installed Bacula Win 3.0.1 under Windows XP without problems.
When i make a folder backup (size 190 Go on my hard disk), Bacula ask for a
second tape (tape one is full with 190,806,491,136 VolBytes).
DltSage utility report : compression is on and 335 Gb are used.
I have tried with "Minimum Block Size = 32768 Maximum Block Size = 32768",
the problem is the same.
My DLT-V4 has the latest firmware (v10) and the latests windows drivers (4.3.33).
Can someone help me ?

That looks perfectly fine to me. I mean 190 GB is greater 160GB. You
do realize that compression depends on the files you back up and if
some of them are already compressed (.zip, .jpg ...) you will not get
close to the often highly optimistic compression rate that
manufacturers state. I expect 1.5:1 on average for drives that state
2:1.

Does your fileset contain a lot of compressed files? Does it contain a
lot of video or audio files?

John

[John Drescher]

I don't know how to reply with the forum; i have create an account, but i
can't find how to do this.
That's i don't understand is why an 320 GB cartridge contains only 190 GB.

But, it really is a 160GB native cartridge and anything more than that
is a bonus. The 320GB is a guess based on if you have what the drive
manufacturer assumes as a typical set of data.

Remember that compression is data dependent so you will never get
exactly 320GB compressed on a 160GB native tape. Also remember that
you typically can not compress data more than 1 time so if any of your
files are compressed (.zip, .gz, .7z, .jpeg, .mp3, .mpeg ...) they
will not compress much if at all. So if you were backing up 160GB of
mpeg data expect that to fill an entire 160/320 tape. However if you
are only backing up text files you would easily fit 500GB of text on
that 160/320 tape.


Can you post the answers to the questions Fabio asked you?

John

[John Drescher]

Hi John.
Do you know how i can post reply in mailing list ?

If you post to either the mailing list or the forum the result should
be sent to the other eventually. I only connect from the mailing list
so there may be a problem with the forum connection or just a delay if
you are seeing something out of sync.
John

[John Drescher]

In file "o0066-dir.Client1.2009-05-11_18.09.52_07.11632008.mail", i found
11-May 18:09 o0066-dir JobId 17: No prior Full backup Job record found.
11-May 18:09 o0066-dir JobId 17: No prior or suitable Full backup found in
catalog. Doing FULL backup.
11-May 18:09 o0066-dir JobId 17: Start Backup JobId 17,
Job=Client1.2009-05-11_18.09.52_07
11-May 18:09 o0066-dir JobId 17: Using Device "DLT-V4"
11-May 18:09 o0066-sd JobId 17: Volume "VS1-0001" previously written, moving
to end of data.
11-May 18:24 o0066-sd JobId 17: Ready to append to end of Volume "VS1-0001"
at file=15.
11-May 18:24 o0066-fd JobId 17: Generate VSS snapshots. Driver="VSS WinXP",
Drive(s)="F"
11-May 22:47 o0066-sd JobId 17: End of Volume "VS1-0001" at 191:24418 on
device "DLT-V4" (Tape0). Write of 32768 bytes got -1.
11-May 22:47 o0066-sd JobId 17: Error: Error writing final EOF to tape. This
Volume may not be readable.
/home/kern/bacula/k/src/stored/dev.c:1723 ioctl MTWEOF error on "DLT-V4"
(Tape0). ERR=Input/output error.

Now the MTWEOF I worry about. Have you ran the btape tests?

11-May 22:47 o0066-sd JobId 17: End of medium on Volume "VS1-0001"
Bytes=190,806,491,136 Blocks=5,822,951 at 11-May-2009 22:47.
11-May 22:47 o0066-sd JobId 17: Job Client1.2009-05-11_18.09.52_07 waiting.
Cannot find any appendable volumes.

You only have 1 available tape?

John

[Fabio Xarax]

Hi!
pls do this
1) on bacula console: estimate of the job and give us the result
2) give us the client/fileset configuration
3) on bacula console: list volumes and give us the result
4) did you set the use of the tape once?

so we can see if it's a TAPE problem, a definition problem or another thing
;)

Bye

[Fabio Xarax]

Hi Thierry,

Hi Fabio.

Post by Fabio Xarax
1) on bacula console: estimate of the job and give us the result
How may i do this ?

in the same way you get "list volumes" ;)
or, as you are on windows OS, open cmd prompt and write "bconsole" (try
...i'm not on Win!)
in the bacula console type "estimate"
then you get a list of jobs -> select the one you want
wait for the result

Post by Fabio Xarax
2) give us the client/fileset configuration
Device {
Name = DLT-V4 #
Media Type = DLT-V4
Device Type = Tape
Archive Device = Tape0
AutomaticMount = yes # when device opened, read it
AlwaysOpen = yes
RemovableMedia = yes
RandomAccess = no
Minimum Block Size = 32768
Maximum Block Size = 32768
Alert Command = "tapeinfo -f %c | findstr TapeAlert"

sorry: no client & fileset info here...

Post by Fabio Xarax
3) on bacula console: list volumes and give us the result
#list volume
Pool: Default
+---------+------------+-----------+---------+-----------------+----------+--------------+---------+------+-----------+-----------+---------------------+
| MediaId | VolumeName | VolStatus | Enabled | VolBytes | VolFiles |
VolRetention | Recycle | Slot | InChanger | MediaType | LastWritten
|
+---------+------------+-----------+---------+-----------------+----------+--------------+---------+------+-----------+-----------+---------------------+
| 3 | VS1-0001 | Full | 1 | 190,806,491,136 | 191
| 31,536,000 | 1 | 0 | 0 | DLT-V4 | 2009-05-11
22:47:12 |
+---------+------------+-----------+---------+-----------------+----------+--------------+---------+------+-----------+-----------+---------------------+
4) did you set the use of the tape once?
Where must i do this ?

see the POOL definition. If you set "Use Volume Once = yes" then every
backup use only one TAPE (or VTAPE ;) )
Or you can check "Maximum Volume Jobs".
I thinkl bacula manual can help you very well (chapter5: the pool resource)

Post by Fabio Xarax
Thierry

I agree with John:compression can't help you on data that can't be
compressed (as .jpg & so on) ;)

bye
Fabio

[Fabio Xarax]

Hi Thierry,
Last attempt:
-try a first backup with data < of 190 GB (ex: 70GB) and "new/empty" TAPE.
-try a second backup (now total on TAPE = 140GB...still on same TAPE)
-try a third and last backup (total data = 210GB - now bacula must require a
new TAPE....I think! ;) )

if you reach last step with no problem all is ok (configuration, TAPE, etc).