Backup a live/up system running oracle

[jaf]

Hello,

I want to use Veeam backup, but have some questions before I want to start with it:

I want to backup a system with Oracle DB.
I don't want to shutdown the DB while backup.
Of course I know the can result to an inconsistent DB in case of restore.

The system is also us if LVM2.
Can there be a problem with the running system?
can Veeam damage the system or database?
Is Veeam doing file locking or simular things?

Is there a difference how Veeam reads the data from the disk when doIng a full, volume or file based backup?

How does the Changed-Block-Tracking (CBT) works an where does it save its data? Is is possible that this function is filling the file system on the backup source?


Thank you

Br johannes

[PTide]

Hi,

Can there be a problem with the running system?

Not with the system, but with the backup session. In case the data change rate is very high you might get a snapshot overflow, which means that there is not enough space to keep all changes for the period the session runs. That will casue backup job to fail. In such case VAL will increase snapshot size automatically and attempt a three retries.

can Veeam damage the system or database?

No, it can't, unless you change the default settings to extreme values without consulting our support team first.

Is Veeam doing file locking or simular things?

No, it's not. VAL uses Copy-on-Write snapshot to ensure filesystem consistency.

Is there a difference how Veeam reads the data from the disk when doing a full, volume or file based backup?

Full and volume backups are the same thing, blocks are copied to the target storage from source device. During file-level backup VAL copies files as a whole + their attributes.

How does the Changed-Block-Tracking (CBT) works an where does it save its data? Is it possible that this function is filling the file system on the backup source?

No, it is not possible. Kernel module keeps CBT data in memory (if you reboot the host VAL will perform full rescan) and it takes negligibly small amount of space to keep that data. Every time something is written to a block, kernel module saves current index value to the corresponding array cell. During next incremental run VAL compares the values with the values that are kept in a backup file, and copies only those blocks that have different (higher) value.

[DavidT666]

Hi,

I am very interesting on veeamsnap.

Last night, our Oracle server crashed during VAL backup.

Code: Select all

Feb 16 23:15:00 hostname kernel: ERR veeamsnap:snapshotdata.c:__snapshotdata_write_dio_request_to Cannot store data to snapshot. Not enough space.
Feb 16 23:15:00 hostname kernel: ERR veeamsnap:snapshotdata.c:snapshotdata_SetCorrupted Now snapshot corrupted.

We have opened a new case #02074222

In our case the data change rate is very high on our Oracle server. In previous case #02015519, Veeam support tell us to use limitFreePercent=90 but we don’t know how this setting works !

Currently we have disabled VAL job on Oracle server until issue was not resolved.

We need to know how veeamsnap works in deep, someone can help us ?
Is it normal that settings in veeam.ini is different between linux server when we do standard install ?

Someone could explain me the settings in veeam.ini plz ? There is no documentation on veeamsnap settings…

[snapshot]
# Free percent of storage. Used for calculate optimal snapshot data size and determinate snapshot data location, not for stretch snapshot
#freePercent= 20 ?

# Location folder for snapshot data, only for 'stretch' and 'common' snapshot
# location= ?

# Maximum possible snapshot data size, not for stretch snapshot
maxSize= 42949672960 ?

# Minimal possible snapshot data size, not for stretch snapshot
minSize= 1073741824 ?

# Snapshot data type, can be 'stretch' (default) or 'common'
# type= ?

# Used percent of storage. Used for calculate optimal snapshot data size and determinate snapshot data location, not for stretch snapshot
usedPercent= 10 ?

LimitFreePercent= 90 ?

[stretchsnapshot]
# Stretch snapshot data portion
portionSize= 2147483648 ?

# Free percent of storage. Used for determinate snapshot data location. Only for stretch snapshot
storageFreePercent= 20

Thanks for your help
David

[PTide]

Hi,

Is it normal that settings in veeam.ini is different between linux server when we do standard install ?

Not sure what you mean, please provide an example of the differences.

Someone could explain me the settings in veeam.ini plz ? There is no documentation on veeamsnap settings…

That info is not for public usage, will reply in PM.

Thank you.

[DavidT666]

Is it normal that settings in veeam.ini is different between linux server when we do standard install ?
Not sure what you mean, please provide an example of the differences.

On one linux server, some settings are not present while on other linux server settings are present :
[snapshot]
#freePercent= 20
usedPercent= 10
storageFreePercent= 20

[PTide]

usedPercent= 10

This part means that 'common' snapshot algorithm was triggered instead of 'stretch'. That happens only if the filesystem is not ext4 or XFS, is that the case for you system? Could you please share both files and PM me the link so I can download them? Also please tell me which one of them has been modifed manually by either you or our support team.

Thanks