Wednesday, April 25, 2018
Creating a new filesystem with fdisk lvm and mkfs
Creating a new filesystem with fdisk lvm and mkfs
Our Task: Create a new 10GB filesystem to store a package repository for yum
Challenges: The existing hard drive has been fully allocated using LVM.
Solution:
- Add a new hard drive to the server (virtual server in this case)
- Partition the drive and add it to the main logical volume
- Create a new filesystem
This article assumes that by now you have physically added the hard drive to the server. In my case I am using a virtual server but the tasks are essentially the same.
Partition the new disk drive
Before starting I will verify there are no partitions on the new disk.
[root@fedora-test ~]# fdisk -l /dev/sdb
Disk /dev/sdb: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders, total 41943040 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 identifier: 0x00000000Disk /dev/sdb doesnt contain a valid partition table
Since there are no partitions it is safe to proceed. I will now create one big partition as I plan to add this disk to LVM and use LVM to divvy up my disk space.
[root@fedora-test ~]# fdisk /dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0xe1410716.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content wont be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
Partition number (1-4, default 1):
Using default value 1
First sector (2048-41943039, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-41943039, default 41943039):
Using default value 41943039Command (m for help): p
Disk /dev/sdb: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders, total 41943040 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 identifier: 0xe1410716
Device Boot Start End Blocks Id System
/dev/sdb1 2048 41943039 20970496 83 Linux
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
Once you type w the changes are written to disk.
Add the partition to the volume group
My volume group name is vg_fedoratest and I will now add the new partition to that volume group with the vgextend command. This adds the additional partition space to the volume group for lvm to use.
[root@fedora-test ~]# ls -la /dev/sdb*
brw-rw----. 1 root disk 8, 17 april 6 15:08 /dev/sdb
brw-rw----. 1 root disk 8, 18 april 6 15:08 /dev/sdb1[root@fedora-test ~]# pvcreate /dev/sdb1[root@fedora-test ~]# vgextend vg_fedoratest /dev/sdb1
No physical volume label read from /dev/sdb1
Writing physical volume data to disk "/dev/sdb1"
Physical volume "/dev/sdb1" successfully created
Volume group "vg_fedoratest" successfully extended[root@fedora-test ~]# vgdisplay vg_fedoratest
--- Volume group ---
VG Name vg_fedoratest
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 4
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 2
Act PV 2
VG Size 40.69 GiB
PE Size 32.00 MiB
Total PE 1302
Alloc PE / Size 663 / 20.72 GiB
Free PE / Size 639 / 19.97 GiB
VG UUID 0gvY4O-I3tT-WKK0-ClU2-sXDz-Nq0c-eExZz2
Create a logical volume & filesystem
I am first using lvcreate to create the logical volume, after verifying that the logical volume created correctly I will create a new filesystem on top with mkfs.
[root@fedora-test ~]# lvcreate -L 10GB -n lv_yumrepo vg_fedoratest
Logical volume "lv_yumrepo" created
[root@fedora-test ~]# lvdisplay vg_fedoratest/lv_yumrepo
--- Logical volume ---
LV Name /dev/vg_fedoratest/lv_yumrepo
VG Name vg_fedoratest
LV UUID rpl7q1-oi6N-nZot-bjPT-Y1qi-2W28-xlBg6Q
LV Write Access read/write
LV Status available
# open 0
LV Size 10.00 GiB
Current LE 320
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:2[root@fedora-test ~]# mkfs -t ext3 /dev/vg_fedoratest/lv_yumrepomke2fs 1.41.14 (23-april-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
655360 inodes, 2621440 blocks
131072 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2684354560
80 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 28 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
Mount the filesystem
Now that my filesystem is created I need to mount it; but before then I need to create the directory that the mount point will overlay and add the appropriate lines to the /etc/fstab file.
[root@fedora-test ~]# mkdir /var/repo
[root@fedora-test ~]# vi /etc/fstab
## Append to bottom
/dev/mapper/vg_fedoratest-lv_yumrepo /var/repo ext3 defaults 0 0[root@fedora-test ~]# mount/dev/mapper/vg_fedoratest-lv_yumrepo on /var/repo type ext3 (rw,relatime,seclabel,user_xattr,acl,barrier=1,nodelalloc,data=ordered)
