Exam EX200 All Questions

View all questions & answers for the EX200 exam

Exam EX200 topic 1 question 51 discussion

Actual exam question from RedHat's EX200

Question #: 51
Topic #: 1

SIMULATION -
One Logical Volume is created named as myvol under vo volume group and is mounted. The Initial Size of that Logical Volume is 400MB. Make successfully that the size of Logical Volume 200MB without losing any data. The size of logical volume 200MB to 210MB will be acceptable.

Show Suggested Answer

Suggested Answer: See explanation below.
First check the size of Logical Volume: lvdisplay /dev/vo/myvol
Make sure that the filesystem is in a consistent state before reducing:
# fsck -f /dev/vo/myvol
Now reduce the filesystem by 200MB.
# resize2fs /dev/vo/myvol 200M
It is now possible to reduce the logical volume. #lvreduce /dev/vo/myvol -L 200M
Verify the Size of Logical Volume: lvdisplay /dev/vo/myvol
Verify that the size comes in online or not: df -h

by Darion81 at Oct. 29, 2020, 2:06 p.m.

Comments

Submit Cancel

Darion81

Highly Voted 3 years, 8 months ago

Why not just lvreduce /dev/vo/myvol -r -L 200M? -r - resize filesystem

upvoted 15 times

ntcct

3 years, 4 months ago

Resizing the LV is just step1. It resize the "holder". To make it be regconized at the "upper" ilesystem lelvel, we need to resize2fs. Im short, there are 5 key components related to LVM disk/volume mgmt: physical storage -> physical partition --> vol group -> logical vol --> file system.

upvoted 1 times

Hmenu0s

1 year, 11 months ago

"-r / --resizefs" option of lvreduce is the recommended approach. Excerpt from RHEL 8 docs - If the logical volume you are reducing contains a file system, to prevent data loss you must ensure that the file system is not using the space in the logical volume that is being reduced. For this reason, it is recommended that you use the --resizefs option of the lvreduce command when the logical volume contains a file system. When you use this option, the lvreduce command attempts to reduce the file system before shrinking the logical volume. If shrinking the file system fails, as can occur if the file system is full or the file system does not support shrinking, then the lvreduce command will fail and not attempt to shrink the logical volume.

upvoted 6 times

...

ms200

Highly Voted 3 years, 2 months ago

lvresize -r -L 200M /dev/vo/myvol

upvoted 12 times

...

VforVodoo

Most Recent 10 months, 1 week ago

# umount /mnt/myvol #e2fsck -f /dev/mapper/vo-myvol #resize2fs /dev/mapper/vo-myvol 200M #lvreduce -l -50 vo/myvol (if PE size was 4.00 MiB) #lvdisplay vo/myvol --LV Path /dev/vo/myvol --LV Size 200.00 MiB --Current LE 50 ---- #mount -a

upvoted 1 times

...

cloudsinair

1 year, 1 month ago

[root@dtop5 ~]# lvreduce -r -L 100M /dev/datastore1/fs1 fsadm: Xfs filesystem shrinking is unsupported. /usr/sbin/fsadm failed: 1 Filesystem resize failed. [root@dtop5 ~]# [root@dtop5 ~]# lvremove /dev/datastore1/fs1 [root@dtop5 ~]# [root@dtop5 ~]# lvcreate -L 150M -n fs1 datastore1 Rounding up size to full physical extent 152.00 MiB WARNING: xfs signature detected on /dev/datastore1/fs1 at offset 0. Wipe it? [y/n]: y Wiping xfs signature on /dev/datastore1/fs1. Logical volume "fs1" created. [root@dtop5 ~]# [root@dtop5 ~]# [root@dtop5 ~]# [root@dtop5 ~]# mkfs.xfs /dev/datastore1/fs1 [root@dtop5 ~]# xfsrestore -f newdump.img /mnt/ [root@dtop5 ~]#

upvoted 1 times

...

hanienarimani

1 year, 7 months ago

-r option is important when using lvreduce , it will resize firesystem too lvresize -r /dev/vgdata/lvbetoche -L 200M

upvoted 1 times

...

kitkat

2 years ago

Anywhere in the question somehow it is not mentioned if file system is ext based or xfs. In both cases steps will be different. I think it would be important to check first that what type of file system is in use before we write answer.

upvoted 1 times

...

kenkct

2 years, 3 months ago

umount /dev/vo/myvol e2fsck -f /dev/vo/myvol resize2fs /dev/vo/myvol 200M mount -a df -hT

upvoted 4 times

kitkat

2 years ago

This should work in case of ext2,3,4 file system.

upvoted 1 times

...

eid

2 years, 5 months ago

in RH8 #df -Th #xfsdump -l 0 -f /myvol.image /dev/vo/myvol #umount /dev/vo/myvol #lvremove /dev/vo/myvol #lvcreate -L 200M -n myvol vo #blkid /dev/vo/myvol #vim /etc/fstab #edit UUID for /dev/vo/myvol #mount -a #xfsrestore -f /myvol.image /myvol #df -Th

upvoted 7 times

cloudyhr

2 years, 5 months ago

To srink the XFS, never use lvreduce command. the above steps by @eid are the correct process. https://logic.edchen.org/how-to-shrink-xfs-file-system-on-enterprise-linux-7-2/

upvoted 3 times

...

kim_ke

3 years, 1 month ago

This works as well lvreduce --resizefs -L 200M /dev/vo/myvol

upvoted 8 times

...