Hey Guys, long time no see…Well i am back and this time the issue is File System.
What Happened ?
Well My Backup Server’s root partition ran out of space due to some issue, and since it was on LVM (Logical Volume Manager) i took some space from my /home partition (it was 400 GB ) and added to my root partition. Following commands were used to resize the partition.
umount /dev/mapper/centos-home lvreduce -L 200G /dev/mapper/centos-home
Note first i unmounted the partition and then reduced the space from my /home partition which was mounted as /centos-home
I took 200 GB out of it and added to my root partition.
The Mistake: I forgot to remount /home to /dev/mapper/centos-home
But i extended the partition with the following command:
lvextend -r -l+100%FREE /dev/mapper/centos-root
As per above command the partition will be re-sized to the 100% free space available from the reduced volume. Of course it was 200 GB. All was good when i saw the partition sized changed from no space to +200 GB. But then i realized that i was not able to mount /home to /centos-home and that was the time when all problem started. I “Rebooted The Machine” and when it came back it refused to enter the normal boot prompt but went into “Emergency mode”
Things i Tried:
I tried to fix the partition with xfs_repair tool , but in vain , and i received the error that “Cannot Find Super Block “
I tried to run the fixes couple of time but failed every time.
I fixed the issue by the following commands:
lvremove /dev/mapper/centos-home lvcreate -L 200GB -n home centos mkfs.xfs /dev/centos/home mount /dev/mapper/centos-home
Luckily there was no important data on my /home partition and i was able to save my server.
If you every fall prey to such situation, remember to “Backup” to an external drive and then proceed with the above mentioned technique to rescue yourself from such difficult situation.
I hope it will help some one some where, Let me know with your feedback.
Thanks & Best Regards,
Salman A. Francis