reduce the lv size

[Viktor Balogh]

>LV extents are a real pain to use and easy to >calculate incorrectly. Use -L #### in MBytes. >If the original size in 15 GB, then lvreduce >-L 15000 is all you need.

Bill, I must neglect it. I prefer to use "-l extent number", because it is a much exact method. To me 15GB is 15*1024 MB which is 15360 MB. 15000MB would be 15GiB, but I dislike these notations anyway. If you stick to the sizes in MB or GB by extending an FS, you can easily get lost between the conversions.

[S.S.]

Thank you Bill Hassell for making me clear.

One more thing:
Actually i have increased to 25gb instead of 15gb right then in that case how can i revert to 15gb?
Following command will revert me to 15gb?

#lvreduce -L 15360

Thank you.

[Johnson Punniyalingam]

You follow below example :- (In this example iam reducing "50MB

step1 :- Backup important ****

step 2 :-# fsadm -F vxfs -D -d -E -e -s /test/testlv -> File system name

step 3 :-# fsadm -F vxfs -b /test/testlv -> File system name

step 4:- # umount /test/testlv -> File system name
(this depends, hence i am not comfortable so i'm unmounting before redcuing)

step 5 :- # lvreduce -L /dev/vg01/lvol4

Warning: rounding up logical volume size to extent boundary at size "52" MB.

When a logical volume is reduced useful data might get lost;

do you really want the command to proceed (y/n) : y

Logical volume "/dev/vg01/lvol4" has been successfully reduced.
Volume Group configuration for /dev/vg01 has been saved in /etc/lvmconf/vg01.conf

More refernce.

# fsadm ???F vxfs ???d ???D ???e ???E
-d perform directory defragmentation
-e perform extent defragmentation
# fsadm ???F vxfs ???b
-b set new file system size to n KB
# lvreduce ???L /dev/vgXX/lvolX
-L set new size of lvol to n MB

[S.S.]

Thank you.