Skip to main content

Lesson Learned On Logical Volume Management and RAID

The lesson is this; that just because you can doesn't mean you should.

I wiped off my RAID array and the data in it. It has around 300+G there, mostly downloaded, recoverable, and back-up'd to a CD/DVD content. I was trying to employ Logical Volume Management or LVM on an existing RAID array. After tackling RAID these couple of months, I figured I'm ready to face another monster. LVM is awesome because it can do partitioning, resizing, formatting, creating snapshots, while the system is online. You do not have to take it offline which to me is like magic.

Now that the data is gone, there really is no reason not to LVM the RAID. So after reinstalling my operating system (which is another long story), I reassemble RAID with:

#mdadm --assemble /dev/md0  /dev/sda  /dev/sdb  /dev/sdc

and checked the status of the array with:

#cat /proc/mdstat
or
#mdadm --detail /dev/md0

I checked the status of all the logical volumes with any of the following commands:

#pvdisplay     ;to check the physical volumes
#vgdisplay     ;to check the volume group
#lvdisplay      ;to check the logical volumes

I know that my home directory is going to need a lot of room for music and videos. I will have to create logical volumes for it to utilize the RAID which is now empty. I would leave some free space there for some flexibility.

To create logical volumes, I plan to extend the existing volume group first to include the newly assembled RAID. So I typed:

#vgextend ubuntu-vg /dev/md0

Then to create the logical volumes I need I typed:

#lvcreate -L size -n Musiclv ubuntu-vg
#mkfs.ext4 /dev/mapper/ubuntu-vg/Musiclv
#lvcreate -L size -n Videoslv ubuntu-vg
#mkfs.ext4 /dev/mapper/ubuntu-vg/Videoslv

I tested mounting them to home directory. I tried:

#mount /dev/mapper/ubuntu-vg/Musiclv /home/user/Music   ;since the Music folder already exist, I don't have to create them.
#mount /dev/mapper/ubuntu-vg/Videoslv /home/user/Videos     ;since the Videos folder already exist, I don't have to create them.

To check if they work, open the file manager, nautilus, and check out properties in particular. If you have trouble with permissions and ownerships of the files, then you should try:

#chmod 777 /home/user/Music
#chown user:user /home/user/Music
#chmod 777 /home/user/Videos
#chown user:user /home/user/Videos

These last series of commands will let you read and write your files and execute operations on them.

To make these changes more permanent so that even if you end your session and reboot they will stay, then we have to edit /etc/fstab file.

#gedit /etc/fstab

Put entries for each lv you created, something like:

                              
    filesystem       mount point        type         options        dump        pass

/dev/mapper/ubuntu-vg/Musiclv    /home/user/Music     ext4     defaults     0       0
/dev/mapper/ubuntu-vg/Videoslv   /home/user/Videos     ext4     defaults     0       0

As the names of the logical volumes imply, I plan to put music and videos on these folders.

Comments

Post a Comment

Popular posts from this blog

ZFS Unable to System Snapshot, bpool is Full?

I first encountered the problem after a routine update / upgrade of the system. Well there was a kernel upgrade and I have not checked how many old kernels are still left for backups in /boot. Apparently, there was a few and the partition is 85% full. Every software update included a warning because of the restriction in disk space. Also, zfs could not create snapshots. It is also full. This is not very clear to me. Snapshots were suppose to be diff copies so why would it take up a large space. Most of the snapshots are less than 2MB. Or 0MB. Another problem that popped up is the constant freezing of Rhythmbox. I don't know if the config files are corrupted. The CPU cycles from one to the next. Peaks for 5-6 seconds then on to the next CPU. This forced me to download Clementine and Audacious. But both applications do not find the zfs pool or don't show the zfs structure. Why not? My final solution is to reinstall Rhythmbox via snaps. I re-scanned the music libr
Post a Comment
Read more

Renter's ID and Business Licensing 2023

Last year's business permit application involved an undertaking of submitting lessee list to the Barangay in order to get them ID's including one for the lessor himself. I received a letter of notification just before New Year's Day. It informed me that I might be denied renewal of permits because I did not comply with this undertaking. So the Renter's ID is a serious thing now. When I went ahead and applied for a business permit renewal at the local government office everything went well except they want my list of lessee. So I had to backtrack and go to the Barangay and submit the list. They produced the ID's and I provided the photo ID's and of course have it signed by the lessee. After that, they pointed me to the cashier to pay the taxes and permit fees which totaled php15,305.00 ($280.33) During the payment of Fire and Safety department, they reminded me to bring my fire extinguisher official receipts of payment. I can pick up my new pe
Post a Comment
Read more

Check rkhunter warnings For Deleted Files

logfile- /var/log/rkhunter.log starts [partial starts] [19:18:58] Info: Starting test name 'malware' [19:18:58] Performing malware checks [19:18:58] [19:18:58] Info: Starting test name 'deleted_files' [19:19:35]   Checking running processes for deleted files    [ Warning ] [19:19:35] Warning: The following processes are using deleted files: [19:19:35]          Process: /usr/bin/pulseaudio    PID: 784    File: /memfd:pulseaudio [19:19:35]          Process: /usr/bin/gnome-shell    PID: 1151    File: /tmp/mutter-shared-67ER4Y [19:19:35]          Process: /usr/bin/pulseaudio    PID: 1173    File: /memfd:pulseaudio [19:19:35]          Process: /usr/lib/evolution-data-server/evolution-source-registry    PID: 1194    File: /home/donato/.local/share/gvfs-metadata/home [19:19:35]          Process: /usr/bin/python2.7    PID: 1472    File: /tmp/vteZY4V4Y [19:19:35]          Process: /usr/bin/megasync    PID: 1484    File: /run/user/1000/wayland-cursor-shared-t6KVCM [19:19:35]    
Post a Comment
Read more