is there any impact on my DB if I performed VG & LV reduce?

[Joaquin_13]

Is there any effect on the database if im going to reduce the logical volume even if I don’t have any data files/oracle files on a certain file system?

Is there any effect on the database if im going to reduce the volume group even if I don’t have any data files/oracle files on a certain file system?
How will it affect my database if im going to use vgred

[Rajeev Shukla]

It wont affect your database if your datafiles are not in the VG and LV which you are going to reduce. But better to take the backup of the LV which you are going to reduce.

Cheers
Rajeev

[Alex Lavrov.]

It's not recommended to perform lvreduce on an LV where you have data stored. It may (and probably will) corrupt the data. Backup it, create a smeller LV and restore the data in to the smaller LV.

[Joaquin_13]

I have already tried reducing a non-important LV & performed vgreduce also in one of our server.But when I check the FS it still have it's original size before i reduce it but when I check the properties of the LV by invoking lvdisplay -v
it appears that it is already been reduced. I have already tried restarting the server but the FS size is still on it's original setup. Is there any way I can reduce the FS?
What does this mean ?

[Alex Lavrov.]

From man:

"WARNINGS
LVM does not store any information about which physical extents within a logical volume contain useful data; therefore, reducing the space allocated to a logical volume without doing a prior backup of the data could lead to the loss of useful data. The lvreduce command on a logical volume containing a file system of greater length than the size being reduced to will cause data corruption."


Now you FS is corrupted, because it's bigger than actual lv size and you need to recreate it.

[Alex Lavrov. · Accepted solution]

In addition you can see these threads where this issue was already discussed:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=149474

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=264447

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=109782

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=660358


And I believe there are more of these :)

[Joaquin_13]

thank's for the info. Luckily i haven't performed it yet to one of our production server.


thank's & regards