backup databse -basic question

[richieasir]

hi all,
could u please explain me the importance of -vs n and -bf n parameter in probkup utility.is their any relationship between the two.how -vs n and -bf n should be defined in the sense based on what?
i wil give u an example:

[richier@hcslnxdba1 sportsDB]$ du -sc *
260 sample_10.d1
260 sample_11.d1
48 sample_7.d1
132 sample_8.d1
48 sample_9.d1
8 sample.b1
960 sample.bkp
660 sample.d1
32 sample.db
4 sample.lg
4 sample.st
2416 total
[richier@hcslnxdba1 sportsDB]$ probkup sample sample.bkp -estimate
1369 active blocks out of 1386 blocks in sample will be dumped. (6686)
0 bi blocks will be dumped. (6688)
The blocksize is 1024. (6994)
Backup requires an estimated 1.4 MBytes of media. (9285)
Restore would require an estimated 1369 db blocks using 1.3 MBytes of media. (9286)
Backup estimate complete. (3739)
[richier@hcslnxdba1 sportsDB]$

the database name is sample and now i like to take both offline and online backupof it,in this case what i want to define in -vs and -bf parameter?how?
please explain me in detail of it?


regards
Richards

 

[taqvia]

-vs specifies the size in blocks. for example probkup <db> c:\db.bk -vs 40 <input.txt will back up the db in multiple voulmes of 40 blocks.if blocksize is 8 KB then 40 * 8 KB will be backed up in each volume.

-bf parameter is the blocking factor.

Explanation of the -bf parameter according to Progress:
Indicates the blocking factor for blocking data output to the backup device. The blocking factor specifies how many blocks of data are buffered before being transferred to the backup device. NT uses a variable block size up to 4K. For all other operating systems, each block is the size of one disk block (1K on UNIX). The primary use for this parameter is to improve the transfer speed to tape-backup devices by specifying that the data is transferred in amounts optimal for the particular backup device. The default for the blocking factor parameter is 34.

if you want to take a multivolume backup specify the value accordingly.

Arshad

 

[TomBascom]

If you are backing up to disk -bf is superfluous.

Most people backup to disk, then use some OS utility to copy those files tape or have some other method of storing the backups safely offsite.

-vs is useful if you are on an old version of Progress and do not have "large file" support (or is your OS does not support large files).

Suppose that your db is 8GB and that you have 4k db blocks and that you cannot create extents larger than 2GB. -vs 250000 combined with 4k blocks means that each backup extent will be 1GB. You might use the following backup command:

probkup sample /backup/sample.bk0 -vs 250000 -com < /backup/backup.list

In the file /backup/backup.list you would have:
/backup/sample.bk1
/backup/sample.bk2
/backup/sample.bk3
/backup/sample.bk4
/backup/sample.bk5
/backup/sample.bk6
/backup/sample.bk7
/backup/sample.bk8

As each extent fills probkup will prompt for the name of the next extent. The redirection from backup.list feeds extent names to probkup. You probably won't use them all since -com will filter out empty and unused blocks and other such fluff.

On disk you will then have half a dozen or so sample.bk* files. That are 1GB. The last one will be shorter. If you use compress or gzip on these you can make them even smaller. Then backup them up to tape or ftp them offsite or do whatever you want to make them safe.

To make an online backup insert "online" between probkup and the dbname.

BTW -- your sample database does not appear to have any after-image extents. Hopefully that's just because you're testing and your real, production, database has after-imaging enabled because there's nothing worse than restoring a backup and then announcing that all the work since the backup was taken has been lost... remember -- crashes always occur just before the backup. Not after. So you generally lose as much data as there is time between backups. After-imaging lets you recover the period between backups. All competent and responsible DBAs run after-imaging.

 

[richieasir]

thanks for ur reply
i could get -vs and its significance.now

1)wat abt -bf,how to define it and based on wat it should be defined?

2)one of my friend who is progress dba who is working with me told me that "if u define -vs,then -bf should be defined.is it true?what is it relationship?
( but without defining -bf, i could able to backup the db(only -vs defined) and restore it)

3)blocking factor-"The blocking factor specifies how many blocks of data are buffered before being transferred to the backup device."
could u please explain the definition?(buffered in the sense....)

regards
Richards

 

[richieasir]

could get -vs and its significance.now

1)wat abt -bf,how to define it and based on wat it should be defined?

2)one of my friend who is progress dba who is working with me told me that "if u define -vs,then -bf should be defined.is it true?what is it relationship?
( but without defining -bf, i could able to backup the db(only -vs defined) and restore it)

3)blocking factor-"The blocking factor specifies how many blocks of data are buffered before being transferred to the backup device."
could u please explain the definition?(buffered in the sense....)

regards
Richards

 

[TomBascom]

Tape drives often benefit from having a blocking factor that is some multiple of the units that they deal in. cpio, tar and dd all support similar options for dealing with tape drives. If you're using probkup to backup directly to tape then you should check with the manufacturer of the drive to see what they suggest. This is basically an attempt to keep the tape streaming rather than having it continuously start and stop as data is ready. It is pointless to specify -bf for anything other than a tape drive.

Frankly I wouldn't backup directly to tape. As indicated, I would first backup to disk. This gives you a lot more flexibility and an extra layer of convenience -- among other things you can recover from that on disk backup while the tape is stuck in traffic on its way to secure off-site storage. You can also compress the disk files prior to writing to tape or before you ftp them somewhere.