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Resizing Hetzner Cloud Block Storage Volumes on the Fly

Today we will be looking into Hetzner’s Cloud Storage Volumes and how you can resize volumes on the fly!

What is Hetzner’s Cloud Storage Volumes

Hetzner Cloud offers a fast, flexible, and cost-effective SSD based Block Storage which can be attach to your Hetzner Cloud Server. At this point in time its available in the Nuremberg and Helsinki regions.

Resizing of Volumes

Volumes can be resized up to 10TB and the console allows you to resize in 1GB increments. You are allowed to increase, but cannot decrease.

Demo through Cloud Volumes

Let’s run through a demo, where we will do the following:

  • Provision a Server
  • Provision a Volume (XFS Filesystem / EXT4 is also optional)
  • Inspect the Volume, do some performance testing
  • Resize the Volume via Hetzner Cloud Console
  • Grow the XFS Filesystem

After provisioning a server, which takes less than a minute, you should see that the server is created:

SSH into your server. At this moment, we have not provisioned any volumes, so only the root partition should be mounted. Look at the block allocation:

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$ lsblk
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      8:0    0 19.1G  0 disk
--sda1   8:1    0 19.1G  0 part /
sr0     11:0    1 1024M  0 rom

Have a look at the fstab:

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cat /etc/fstab
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
UUID=2f54e8e6-ff9c-497a-88ea-ce159f6cd283 /               ext4    discard,errors=remount-ro 0       1
/dev/fd0        /media/floppy0  auto    rw,user,noauto,exec,utf8 0       0

And have a look at the mounted disks layout:

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$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            959M     0  959M   0% /dev
tmpfs           195M  652K  194M   1% /run
/dev/sda1        19G  1.6G   17G   9% /
tmpfs           973M     0  973M   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           973M     0  973M   0% /sys/fs/cgroup
tmpfs           195M     0  195M   0% /run/user/0

Now, time to provision a Volume. Head over to the Volumes section:

I’m going ahead with creating a volume with 10GB of space and assign it to my server, and yeah that’s right, 10GB of storage is 0,40 EUR per month, epic value for money!

After you volume is created, you should see similar output below:

Head back to your server, and have a look at the output when running the similar commands from earlier:

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$ lsblk
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      8:0    0 19.1G  0 disk
--sda1   8:1    0 19.1G  0 part /
sdb      8:16   0   10G  0 disk /mnt/HC_Volume_1497823
sr0     11:0    1 1024M  0 rom

The fstab config:

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$ cat /etc/fstab
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
UUID=2f54e8e6-ff9c-497a-88ea-ce159f6cd283 /               ext4    discard,errors=remount-ro 0       1
/dev/fd0        /media/floppy0  auto    rw,user,noauto,exec,utf8 0       0
/dev/disk/by-id/scsi-0HC_Volume_1497823 /mnt/HC_Volume_1497823 xfs discard,nofail,defaults 0 0

The disk layout:

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$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            959M     0  959M   0% /dev
tmpfs           195M  660K  194M   1% /run
/dev/sda1        19G  1.6G   17G   9% /
tmpfs           973M     0  973M   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           973M     0  973M   0% /sys/fs/cgroup
tmpfs           195M     0  195M   0% /run/user/0
/dev/sdb         10G   43M   10G   1% /mnt/HC_Volume_1497823

We can see from the output above how easy it is to provision a volume to your Hetzner Cloud Server. And everything gets done for you, the disk is mounted and the /etc/fstab configuration is populated for you.

Time for some performance testing on the volume:

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$ dd bs=2M count=256 if=/dev/zero of=/mnt/HC_Volume_1497823/test.dd
256+0 records in
256+0 records out
536870912 bytes (537 MB, 512 MiB) copied, 0.911306 s, 589 MB/s

Pretty neat right? :D

Let’s resize the volume via the Hetzner Cloud Console to 20GB and resize the filesystem. From the Console, head over to the volumes section, select the more options and select resize:

After the volume has been resized, head back to your server and resize the filesystem. As we are using XFS Filesystem, we will use xfs_growfs :

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$ xfs_growfs /dev/sdb
meta-data=/dev/sdb               isize=512    agcount=4, agsize=655360 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1 spinodes=0 rmapbt=0
         =                       reflink=0
data     =                       bsize=4096   blocks=2621440, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal               bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 2621440 to 5242880

Have a look at the disk layout and see that the filesystem was resized on the fly. If you have applications writing/reading to and from that volume, its better to unmount it first.

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$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            959M     0  959M   0% /dev
tmpfs           195M  660K  194M   1% /run
/dev/sda1        19G  2.1G   16G  12% /
tmpfs           973M     0  973M   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           973M     0  973M   0% /sys/fs/cgroup
tmpfs           195M     0  195M   0% /run/user/0
/dev/sdb         20G  565M   20G   3% /mnt/HC_Volume_1497823

I must admit, I am really stoked with Hetzner’s offerings and their performance. I’ve been hosting servers with them for the past 5 months and so far they really impressed me.

Have a look at Hetzner Cloud’s offerings, they have great prices as you can start off with a server from as little as 2.49 EUR per month, which gives you 1vCPU, 2GB of RAM, 20GB disk Space and 20TB of traffic. I mean, thats awesome value for money. They also offer Floating IP’s, Backups, etc.

Resources:

Thank You

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Thanks for reading!

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