topic Re: fbackup to DDS3 in Operating System - HP-UX

fbackup to DDS3

Chirag Parekh — Thu, 28 Apr 2005 07:55:19 GMT

Hi,

I am trying to backup database files which approximates to 36Gb to a DDS3 tape. I tried using the fbackup in a script but it fails as it asks for another tape due to insufficient space on the tape. Is there anyway that I can compress the data to fit it onto the tape.

Thanks.

Re: fbackup to DDS3

Pete Randall — Thu, 28 Apr 2005 08:11:08 GMT

If you use the "BEST" device file, it will automatically choose the highest density/compression available for the device:

/dev/rmt/c6t0d0BEST, for example

Pete

Re: fbackup to DDS3

RAC_1 — Thu, 28 Apr 2005 08:13:01 GMT

Are you using right device file??
How does you fbackup configuration file look like??

Anil

Re: fbackup to DDS3

Patrick Wallek — Thu, 28 Apr 2005 08:16:24 GMT

This entirely depends on your data. The "normal" assumption for DDS3 is 24GB compressed (assuming 2:1 compression) and 12 GB native.

If you data is very compressable it is possible to get 36GB on a single tape. If it is not very compressable, there's no way.

At this point, I'd say yours is the latter case.

Can you upgrade to a DDS4 tape drive? That *should* handle it.

Re: fbackup to DDS3

Chirag Parekh — Thu, 28 Apr 2005 08:17:48 GMT

Hi RAC,

Below is the config file:

more fbackup_config
blocksperrecord 32
records 32
checkpointfreq 32
readerprocesses 2
maxretries 5
retrylimit 5000000
maxvoluses 100

Thanks.

Re: fbackup to DDS3

Chirag Parekh — Thu, 28 Apr 2005 08:20:28 GMT

Hi Patrick,

The server in question is overseas and it is currenlty not possible to upgrade the DDS drive. The files is question are Oracle database files. Any idea on compressing them further before putting them on tape.

Thanks.

Re: fbackup to DDS3

Chirag Parekh — Thu, 28 Apr 2005 08:20:36 GMT

Hi Pete,

I did a lssf /dev/rmt/* and used the device which had a BEST in the description. I am currently using /dve/rmt/0m.

Re: fbackup to DDS3

Patrick Wallek — Thu, 28 Apr 2005 08:35:17 GMT

We have an inhouse written backup script that does the following:

Puts the DB in backup mode and does

compress < /path/to/oracle/db/files > /backup/of/oracle/db/files.Z

for all data files. At the end it deals with all of the archive logs. We have a dedicated filesystem for these backups.

Now once the above is done, we know almost exactly how much tape will be requuired.

You could do something very similar and experiment between compress and gzip. You could even try 'gzip -9' which is slower but can compress a whole lot more efficiently than just 'gzip'. You can use the same syntax as above to redirect the input and output of gzip as well.

I would do this with the DB in backup mode or with the DB down completely. Otherwise your backup will be essentially useless.

Re: fbackup to DDS3

Chirag Parekh — Thu, 28 Apr 2005 08:47:54 GMT

Hi Patrick,

I running the fbackup thru a shell script which brings the database down before the backup.

The DB is spread over multiple FS. Can I compress and write to the tape using fbackup single FS as a time w/o overwriting the previous FS for that day - meaning can I compress /u01 and write it to tape, then compress /u02 and write it to tape and so on ..... The reason being we do not have a spare storage disk to allocate to the server and as I said as the server is overseas we do not have a dedicated Unix guy over there. We do remote administration of the server.

Thanks.

Re: fbackup to DDS3

Patrick Wallek — Thu, 28 Apr 2005 08:55:15 GMT

No, fbackup will ALWAYS rewind the tape before it starts backing up. That's just the way it works. If you run fbackup twice on a single tape, you will only have your second backup.

Re: fbackup to DDS3

Chirag Parekh — Thu, 28 Apr 2005 09:08:38 GMT

Hi Patrick,

I am using the below command to kick off the backup:

/usr/sam/lbin/br_backup DAT FULL Y /dev/rmt/0m /var/sam/graphJCAa08437 Y 1 N > /var/sam/SAM_br_msgs 2>&1

Is there any option that can be turned on that can help?

Thanks.

Re: fbackup to DDS3

Hoang Chi Cong_1 — Thu, 28 Apr 2005 22:20:06 GMT

You can not backup 36 GB to a DDS3 tape even compressed. At least, you have got DDS4.
I think no compress tool available!

Regard,
HoangChiCong