Open Telekom Cloud This book is about using the Open Telekom Cloud (OTC) for server provisioning. It is considered a handbook for LibScie's purposes (for example, we use it for our Single Sign On (SSO) services). We share it for your corporate enjoyment and provide zero guarantees. Here is a quicklink to the OTC console. OTC provides various sources of documentation, which this only seeks to complement. See also the documentation, the forum (requires an account), and the official certifications. OTC is currently only available to registered businesses, so if you are considering this as a private individual, it is not possible to set up an account. See also the OTC Academy. We make a few assumptions for this wiki: We assume you run a Linux or macOS deviceYou have an OTC account with the appropriate permissions Use your best judgement in following our tips and tricks – they are provided without guarantee :-) Elastic Cloud Server (ECS) These are traditional virtualized servers, which you can manage from the Operating System (OS) through the exposed ports. This also means you are responsible for managing the OS and its security.   Elastic Volume Service (EVS) EVS is flexible disk provisioning for Elastic Cloud Server (EVS). Use this for production deployments where needed, so that the disk space can flexibly expanded. This prevents the need for compute migrations that cause more overhead. EVS Setup Go to the EVS portal "Create disk" Choose the region of your destination server (for optimal performance) Choose "General Purpose SSD" Choose somewhere between 10-25GB Encrypt the volume according to the threat model (if unknown, evs/default ) Optional: Add informative tags (for example, libscie=sso ) Give an informative name (for example, org.libscie.git for the service on https://git.libscie.org ) We recommend using one EVS per production service, to allow for compartmentalization of disks per service. Services may be on the same server at this time, but that is not a guarantee it will remain so. Note that disk space can be expanded at any time in the future, so if you are unsure about your needs, pick 25GB to start. Attaching EVS to ECS Upon creation of your EVS, it will need to be attached to be useful (see also OTC docs ). If you created an EVS during the server creation, it will already be attached! Conceptually, you will partition, format, and attach the disk. Partitioning SSH into the server Run fdisk -l or lsblk to identify the newly attached drive Run fdisk /dev/vdb (double check the drive with results from step 2) to start formatting the disk Return n to initialize the formatting Return p to setup one primary partition Take the default values for the next three steps (that is, press Enter three times) Optional: Check the partitions by returning p Return w to write partitions to disk Formatting Run partprobe Run mkfs -t ext4 /dev/vdb1 (double check the ext4 and /dev/vdb1 for your scenario) Attaching (aka "mounting") Identify the path where you want the disk to be attached (for example, /mnt/evs-disk ) Run mount /dev/vdb1 /mnt/evs-disk (replacing the disk and attachment path) This attaches the drive until the server is rebooted. Attaching the disk upon boot Find the UUID for the disk blkid /dev/vdb1 /dev/vdb1: UUID="905943cb-c59b-401d-b686-22e0c1131869" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="fae0084f-01" Open the config file: nano /etc/fstab Add a new line with the specific mount information, for example UUID=905943cb-c59b-401d-b686-22e0c1131869 /mnt/evs-disk ext4 defaults 0 2 Unattach the manually attached drive: umount /dev/vdb1 Reload the fstab config - run systemctl daemon-reload Check your disk is attached Expanding existing EVS https://docs.otc.t-systems.com/elastic-volume-service/umn/expanding_evs_disk_capacity/index.html https://docs.otc.t-systems.com/elastic-volume-service/umn/expanding_evs_disk_capacity/extending_disk_partitions_and_file_systems_linux/extending_partitions_and_file_systems_for_data_disks_linux.html#evs-01-0109-en-us-topic-0044524728-section31113372194023 Migrating an EVS between servers Elastic Volume Services (EVS) can be unmounted and remounted on another Elastic Cloud Server (ECS) as needed. However, be careful to not multi-mount an EVS, considering it is not made for this purpose. Elastic Volume Service (EVS) is made for single mount only, multi-mount is possible with a Scalable File Service (SFS). Conceptually, migrating and EVS is simple: Unmount from current server and mount onto the new one. Be sure to create a backup prior to prevent any data loss! Go to your current server and stop the services using the drive Unmount the drive: sudo umount /dev/vdb1 (adjusted for your drive, see df ) Go to the OTConsole and detach the drive from the Elastic Cloud Server (ECS) Attach the drive to the new Elastic Cloud Server (ECS) Find the relevant drive using sudo lsblk (check for the sizes) Add the mount point to /etc/fstab to ensure it is mounted upon boot Cloud Container Engine (CCE) CCE is currently still in beta. Last attempt at using it was buggy. In order to push a docker image to the image repository, take the following steps: # log in # build Image (optional) # tag image docker tag {Image name}:{Tag} swr.eu-de.otc.t-systems.com/{Organization}/{Image name}:{Tag} # push docker image to swr docker push swr.eu-de.otc.t-systems.com/{Organization}/{Image name} Reserved Packages All services on the Open Telekom Cloud (OTC) are paid as-you-go by default. These are pro-rated per minute. If you know the services are long-lasting, it is worth paying for Reserved Packages, which come in 12-24 month contracts. You can book Reserved Packages in the eShop. Reserved Package booking through the OTC eShop has proven failure-prone. Please note you may need to plan for more time and getting service support ( service@open-telekom-cloud.com ). Booking a Reserved Package When booking a reserved package, you will have to go through the configurator to find the right service. If your service already exists (for example, db.x1.large.2.ha | 2 vCPUs | 4 GB (Dedicated) ) it is critical that the reserved package matches. Reserved packages are a purely billing instrument. This means if you reserve a new service, it is not created for you in the console. Example calculation To highlight the reduced costs when booking a reserved package, we will highlight the different prices for db.x1.large.2.ha | 2 vCPUs | 4 GB (Dedicated)   in the table below. All total prices are for 24 months, to make them comparable. "Reserved – Monthly" means the service is reserved for the duration of the contract, but still paid monthly. "Upfront Reserved" is a lump sum payment for the contract duration. The "As you go" price is determined using the Open Telekom Cloud (OTC) Price Calculator . Duration Price Total (24 months) As you go (monthly) €194.20 €4,660.80 12 months (Reserved - Monthly) €147.60 €3,542.40 12 months (Upfront Reserved) €1,515.00 €3,030.00 24 months (Reserved - Monthly) €135.94 €3,262.56 24 months (Upfront Reserved) €2,157.00 €2,157.00 The biggest difference is ~2 times more expensive, which means that you can save around 50% of costs just by reserving the service and paying up front. That is a massive cost saving. However, the downside is that you are less flexible – there is a balance to find in there. Not all services will have the same price development, so it is worth checking every time.