After watching the videos on disk management I have a lvm question.

I have Centos 6.5 running as an addc with samba 4 on a 2 tb hdd and I have a windows 7 ultimate box as a client. I have a shared network drive drive "S", on the windows box, that points to /srv/samba/ on my centos box. /srv/samba has users,movies,photos,,music under it which are listed in smb.conf file and that I can see on the windows box. I am running out of space on my shared network drive "S"

My question is using lvm can I increase the size of my network shared drive "S" If I can how do I mount the shared drive so that I will see the new size on the windows box network share drive "S"

Thank You
John Guarnieri

Hey John,
It sounds like what you want to do is create a lvm volume group. You can add a new drive and extend the lvm to group the two drives together and your Windows machine should just see the same share, just with more space.

You will need to add the new drive to the system and then partition and format. Once that is done, you need to set the new partition to be a lvm physical drive. So if the current 2Tb drive is hda1 and the new drive is hdb1 then run...

sudo pvcreate /dev/hdb1

This adds the hdb1 disk as a physical lvm disk.
Then create a physical volume group if you haven't already.

sudo vgcreate sdrive1 /dev/hda1 (you have to give it a group name so I just put sdrive1)

Now we need to extend the physical volume group to include hdb1

sudo vgextend sdrive1 /dev/hdb1

Now we need to do the same for the logical volume.

sudo lvextend sdrive1 /dev/hdb1

I think you then need to run something like resize2fs or xfs_growfs to have the system recognize the new size of the volume and then you should be all done. Plus I'm fairly sure that the Windows client will just see the same share with increased size. Maybe you will need to reconnect the share to the client, but I'm not sure.

Yes but my question is the mounting part. Can I mount s:/srv/samba that is what the window box points to as a shareed network drive. I feel like it's already mounted by windows and I want to mount it again with the lvm. I am confused on the mounting part and I don't want to break my network share.

Thanks

Assuming you have a share on your linux box for /srv/samba, then your windows machine will mount something like \servername\sharename, where servername is the name of your linux machine and sharename is the name of the share pointing to /srv/samba.

The SAMBA share will share everything in the /srv/samba folder and reflect the size of the filesystem that /srv/samba is on. So if the size of the filesystem is 1GB today and tomorrow, via LVM, you extend the disk to 4GB and tell the filesystem it is 4GB, then SAMBA will automatically see the new 4GB total size and windows will also see that as soon as SAMBA sees it.

Cheers.

I'm new here and found this old question and didn't like the answer given, so I thought I'd add my two cents.

First, there's a bit of mis-information on 'properly' setting up LVM around how to prepare the physical disk.

The video shows using a raw device such as /dev/sdb and adding that to a volume group. On real hardware, NEVER do this. The short answer here is that you want your filesystem blocks to align with your backend storage blocks, else you will suffer from worse performance than if you do this properly. You'll really notice this if you're using a SAN or EBS on AWS. If you're on an SSD, you're less likely to notice at all unless you're running the maximum IOPS the device can support.

So, in your question, you have /srv/samba. If that is on the same physical device as your / mount, then we're going to have to do some moving of data after adding a drive. That's easy. I'll go ahead and assume that is the case.

Add a new physical drive. We'll assume here that your existing drive is /dev/sda (and on it you have multiple partitions). Your new drive we will assume is now /dev/sdb. Please be sure you KNOW what the new device name is, or you're going to have a bad day when we erase it in a moment.

You can double-check the devices you have by using either cat /proc/partitions to see what partitions your OS recognizes, or run lsblk for an excellent view of your devices and where they are mounted. Use this information to be sure you are configuring the correct device.

To prepare the new disk, we need to partition it. Here's the part the video missed. If the new disk is more than 2TB, you can use fdisk without an issue, and you'll need to use the new GPT partition. Newer versions of fdisk know about GPT, which will allow you to partition a disk larger than 2TB. If you don't have a newer system with the fdisk that knows about GPT, then you'll want to use something like parted.

sudo fdisk /dev/sdb

Now that you're in fdisk editing the new disk you've added, let's add a GPT partition to this disk.

Menu option 'g' will set up a GPT instead of a MBR partition table which is required for all drives larger than 2TB. This also puts fdisk in GPT mode.
Then we want to add a new partition, so press menu option 'n'.
Take the default partition of '1' by pressing 'ENTER'.

Here's where fdisk will detect the block alignment of the device. For most storage options, it will default to sector 2048 as the beginning sector of the new partition.
Take the default by pressing 'ENTER'.
If you want to use all of the free space on the disk, this is the default, so press 'ENTER'.
The new partition is created and ready to be written to disk, but we want to mark it with the LVM type, not the default Linux filesystem type. Press menu option 't' to change the type, and specify type '15' which is the Linux LVM type in GPT mode. (It is type '8e' in MBR mode). When you press 'ENTER' you're ready to write the changes to disk by pressing menu option 'w' and 'ENTER'.

You can confirm the changes were written to disk by using sudo fdisk -l /dev/sdb (that's the lower-case L) and examine the output. Here's mine:

Disk /dev/sdb: 2199.0 GB, 2199022206976 bytes, 4294965248 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: gpt

Start End Size Type Name

1 2048 4294965214 2T Linux LVM

(I only have a 2TB partition because that's the maximum my VM host will allow)

Your kernel may or may not pick up the new disk partition. Check to see if /dev/sdb1 shows up in the output of cat /proc/partitions or lsblk. If it does, you're golden. If it doesn't, try running sudo partprobe to see if it shows up. If it still doesn't show up, reboot, and then it should be there.

Here's where we tag the new partition as a LVM physical volume.

sudo pvcreate /dev/sdb1 - this writes the meta-data to the disk so LVM will identify it as a member disk.

The next step assumes you do NOT already have LVM configured to use a Volume Group. If you do, you don't need to create a new one, so skip this step:

sudo vgcreate sambadata /dev/sdb1

Now we have a Volume Group named 'sambadata'.

Next step is to create a Logical Volume in the Volume Group. This is where we will lay our filesystem.

sudo lvcreate -n sambalv --extents 100%VG sambadata

Next, create your filesystem of choice. If you want to use xfs, for example:

sudo mkfs -t xfs -L samba -i maxpct=100 /dev/mapper/sambadata-sambalv

You now have a mountable filesystem on device /dev/mapper/sambadata-sambalv that you can later grow larger as you add more drives.

Let's mount this somewhere so I can move all my existing data onto it:

sudo mkdir -p /mnt/sambatmp
sudo mount /dev/mapper/sambadata-sambalv /mnt/sambatmp/

To get all the data sync'd up to the new location, I use rsync. The reason for this is that I can leave Samba running while these files get copied, so if I have a lot of data, I don't have to take the server down while I'm moving data. (This will slow down the server significantly.)
You can always press 'CTRL-C' to interrupt the rsync process and restart it later.

sudo rsync --delete -av /srv/samba/. /mnt/sambatmp/

I put the '--delete' in there so when I run it again later, it will remove any files from the new location that were deleted from /srv/samba. The -a preserves ownership, permissions, timestamps, etc.

Once this command completes, the samba server will need to be stopped to make sure files aren't changing (and this will detach any active Windows mounts). Then, let's run a final rsync and move the existing files out of the way so I can mount the new disk in place:

sudo rsync --delete -av /srv/samba/. /mnt/sambatmp/
sudo umount /mnt/sambatmp
sudo mv /srv/samba /srv/samba-old
sudo mkdir /srv/samba
sudo mount /dev/mapper/sambadata-sambalv /srv/samba

Restart your samba server to use the new LV on the newly added disk.

Finally, update your /etc/fstab to mount /dev/mapper/sambadata-sambalv at the /srv/samba location using the options you want. This is necessary so that your new disk's LV will be mounted after a reboot.
The added line might look something like this:

/dev/mapper/sambadata-sambalv /srv/samba xfs rw,relatime,seclabel,attr2,inode64,noquota 0 0

Since we moved the /mnt/samba to /mnt/samba-old, all of your original files are here. Once you're sure the new mointpoint is all happy, you can delete this directory and recover all of that used space.

sudo rm -R /srv/samba-old