I am currently trying to backup an empty SQL Server 2008 R2 database that I designed for a project that is getting shelved for the time being. I was going through the back up procedure through the SQL Management Studio when I noticed there was an option to make a Copy Only Back Up. I looked it up to see what it was but I didn't fully understand the options I was getting.
http://technet.microsoft.com/en-us/library/ms191495.aspx
I read the entry above as well as other entries and I keep seeing the phrase "independent of the sequence of conventional SQL Server backups."
Can anyone elaborate what this statement means or more about Copy Only Backups in general? I'm not sure if it's the backup I should do in this case? (My first reaction is no)
It's a full dump of a database, where you intent to take that dump and load it into some OTHER sql server instance. e.g. It's a nice way of making a complete copy of a DB without having to take down the db, detach the db, copy the .mdf files, re-attach, etc...
Naturally, since you're not using this "backup" as an actual backup, you don't want it to interfere with your normal backup schedules, hence the copy-only functionality. It's a full backup, but will not reset the backup schedule, so your normal next incremental/snapshot backup will work as usual.
This mechanism is necessary since the built-in hotcopy/migration tools in MSSMS are basically useless and can't handle its own databases in many cases.
Normally when you take a backup, it starts (or continues, depending on the type of backup that you took) what is called a log chain. Let's say that you need a copy of your database and, for whatever reason, you can't use your normally scheduled backups for this purpose. Let's walk through the scenario where you don't use a copy_only backup
Normal full backup
A bunch of differential backups
Another full backup (to make your copy database)
More differential backups
Delete the backup from step 3 (you know... to save space)
Disaster on your actual database that necessitates restore from backup
In this case, you can only restore to the last differential backup made in step 2 because the differential backups made in step 4 depend on the full backup from step 3. Now, if the backup in step 3 were a copy_only backup, you'd be fine because you're not re-establishing a log chain (which is to say that the differential backups in step 4 depend on the full backup from step 1.
If you are creating an archive backup and continuing to back it up on the server is not a concern, then it doesn't matter whether you use it or not. It will be restorable as the database either way.
Related
I have to create script which will create the database locally (from database which is on server). Database is 20GB+ and every day is bigger.
What is your advise to do that? I can generate script with all database objects in SSMS, but how operate with data insertion? I mean full script (script which includes data) is not good option. What about one Full Backup and Differetial Backups?
Run generated scripts for all DB objects
Restore Full Backup
Restore Differential Backup
This work is required in order to make possible to test the app locally, on my (another dev's) machine. Thank for every advise!
My advice is to go with a full backup first & get differential backups afterward.
Because a differential backup is not independent and it must be based on the latest full backup of the data. That means there should have a full backup as a base. A differential backup contains only the data that has changed since the differential base. Typically, differential backups are smaller and faster to create than the base of a full backup and also require less disk space to store backup images.
Therefore, using differential backups can save available space and also speed up the process of restoring. At restore time, the full backup is restored first, followed by the most recent differential backup.
I have been building an application to Backup SQL Databases using VDI using SMO.
I have a doubt whether i should be capturing the last backup time of a database along with the LSN or simply, just capture the LSN.
More precisely, i wanted to take Last Backup Time to know that if end-user is using another software to backup their SQL DB's using Copy-only method since copy-only method doesn't update LSN or truncate anything but does update the Last backup time.
So, if i am ignoring the last backup time information of any DB and simply capturing the LSN, is it going to cause any problems for me? in terms of recovery/backup if there are other 3rd party softwares into play?
:::: Edit :::::
I am a backup application developer and i would like to know, should i be capturing the Last Backup time of the database that my end-user would like to backup ? or just simply capture the LSN to maintain the Log chain?
If you're writing your backup software for the purposes of ensuring recoverability (that is you're not taking copy-only backups yourself), don't worry about any copy-only backups that have been taken by others. As you've said, copy-only backups don't affect the backup chain.
The only thing that would mess you up is if someone else is taking a non-copy-only backup interleaved with yours. In that case, you could get into a situation where one of their backups relies on one of yours (or vice versa) and the restore scenario is complicated at a point where it really shouldn't be (i.e. the database is down and you need to recover it).
Given a SQL Server 2008 .bak file, is there a way to restore the data file only from the .bak file, without the transaction log?
The reason I'm asking is that the transaction log file size of this database is huge - exceeding the disc space I have readily available.
I have no interest in the transaction log, and no interest in any uncompleted transactions. Normally I would simply shrink the log to zero, once I've restored the database. But that doesn't help when I have insufficient disc space to create the log in the first place.
What I need is a way to tell SQL Server to restore only the data from the .bak file, not the transaction log. Is there any way to do that?
Note that I have no control over the generation of the .bak file - it's from an external source. Shrinking the transaction log before generating the .bak file is not an option.
The transaction log is an integral part of the backup. You can't tell SQL Server to ignore the transaction log, because there is no way to let's say restore and shrink the transaction log file at the same time. However, you can take a look at DBA post to hack the process, although it is not recommended at all
Alternatively you could try some third party tools for restoring, particularly virtual restoring process that can save a lot of space and time. Check out ApexSQL Restore, RedGate Virtual Restore, Idera Virtual Database.
Disclaimer: I work for ApexSQL as support engineer
No, the transaction log is required.
Option 1:
An option may be to restore it to a machine that you DO have enough space on. Then on the restored copy change the logging to either bulk logged or simple, shrink the logs, do another backup operation on this new copy and then use that to restore to the target machine with the now much smaller transaction log.
Option 2:
Alternatively, perhaps the contact at the external source could shrink the transaction log before sending it to you (this may not work if the log is large due to a lot of big transactions).
Docs on the command to shrink the log file are available here.
This is really a question for the ServerFault or DBA sites, but the short answer is no, you can only restore the full .bak file (leaving aside 'exotic' scenarios such as filegroup or piecemeal restores). You don't say what "huge" means, but disk space is cheap; if adding more really isn't an option then you need to find an alternative way of getting the data from your external source.
This may not work since you have no control over the generation of the .bak file, but if you could convince your source to detach the database and then send you a copy of the .mdf file directly, you could then attach the .mdf and your server would automatically create a new empty transaction log file.
See sp_detach_db and sp_attach_db (or CREATE DATABASE database_name FOR ATTACH depending on your sql server version).
I know this is an old thread now, but i stumbled across it while I was having transactional log corruption issues, here is how I got around it without any data loss (I did have down time though!)
Here is what I did:--
Stop the sql server instance service
make a copy of the affected database .mdf file and .ldf file (if you have an .ndf file, copy that as well!) - Just to be sure, you can always put these back if it doesn't work for you.
restart the service.
Log into sql management studio and change the database mode to simple, then take a full backup.
Change the database type back again and once again take a full backup, then take a transactional log backup.
Detach the database.
Right click on databases and click on restore, select the database name from the drop down list, select the later full database backup created (not the one taken from the simple mode) and also select the transactional log backup.
Click restore and it should put it all back without any corruption in the log files.
This worked for me with no errors and my backups all worked correctly afterwards and there were no more transactional log errors.
I'm using SQL Server 2005.
I need to move a database to a new server with minimum downtime.
Currently my option is to take everything offline, perform a backup, copy the backup to the new server, restore the backup and bring everything back online.
The problem here is that the backup file is about 10Gb, therefore, it takes about 5-10 mins to perform this whole operation.
I've heard of people performing a full backup with everything online and then doing a differential backup so there is less to copy over.
I've taken the full backup, copied that to the new server and restored it. I've then taken a differential backup and copied it to the new server.
The problem is, when I try and restore this backup I get the message "The log or differential backup cannot be restored because no files are ready to rollforward."
I have also tried selecting both the full and differential backup but then I get the error "The volume on device 'D:\FullBackup.bak' is not part of a multiple family media set. BACKUP WITH FORMAT can be used to form a new media set."
Does anyone know what I'm doing wrong and what the easiest way of doing this is?
Thanks
It seems you did not set the NORECOVERY option on the full RESTORE.
You need this option to leave all transactions intact so that you can apply the differential backup later.
If you don't set it, the uncommited transactions get rolled back while restoring the full backup, and the last LSN of the database becomes greater than the first LSN of the differential backup.
Another quick way of doing this is to Detach the database, and then copy the underlying .mdf and .ldf files for your DB straight to the DB, then reattach. Time taken to copy a 10GB file will be much less than the Backup, and it acheives the same thing.
I have one database which contains the most recent data, and I want to replicate the database content into some other servers. Due to non-technical reasons, I can not directly use replicate function or sync function to sync to other SQL Server instances.
Now, I have two solutions, and I want to learn the pros and cons for each solution. Thanks!
Solution 1: detach the source database which contains the most recent data, then copy to the destination servers which need the most recent data, and attach database at the destination servers;
Solution 2: make a full backup of source server for the whole database, then copy data to destination servers and take a full recovery at the destination server side.
thanks in advance,
George
The Detach / Attach option is often quicker than performing a backup as it doesn't have to create a new file. Therefore, the time from Server A to Server B is almost purely the file copy time.
The Backup / Restore option allows you to perform a full backup, restore that, then perform a differential backup which means your down time can be reduced between the two.
If it's data replication you're after, does that mean you want the database functional in both locations? In that case, you probably want the backup / restore option as that will leave the current database fully functional.
EDIT: Just to clarify a few points. By downtime I mean that if you're migrating a database from one server to another, you generally will be stopping people using it whilst it's in transit. Therefore, from the "stop" point on Server A up to the "start" point on Server B this could be considered downtime. Otherwise, any actions performed on the database on server A during transit will not be replicated onto server B.
In regards to the "create a new file". If you detach a database you can copy the MDF file immediately. It's already there ready to be copied. However, if you perform a backup, you have to wait for the .BAK file to be created and then move it to it's new location for a restore. Again this all comes down to is this a snapshot copy or a migration.
Backing up and restoring makes much more sense, even if you might eek out a few extra minutes from a detach attach option instead. You have to take the original database offline (disconnect everyone) prior to a detach, and then the db is unavailable until you reattach. You also have to keep track of all of the files, whereas with a backup all of the files are grouped. And with the most recent versions of SQL Server the backups are compressed.
And just to correct something: DB backups and differential backups do not truncate the log, and do not break the log chain.
In addition, the COPY_ONLY functionality only matters for the differential base, not for the LOG. All log backups can be applied in sequence from any backup assuming there was no break in the log chain. There is a slight difference with the archive point, but I can't see where that matters.
Solution 2 would be my choice... Primarily becuase it won't create any downtime on the source database. The only disadvatage i can see is that depending on the database recovery model, the transaction log will be truncated meaning if you wanted to restore any data from the transaction log you'd be stuffed, you'd have to use your backup file.
EDIT: Found a nice link; http://sql-server-performance.com/Community/forums/p/5838/35573.aspx