Storage options
You have the option of local storage or SAN (portable SAN) for each virtual server. You can supplement local storage or SAN with other storage products as needed.
Local storage
Local storage is built on disks that are local to the virtual server host. Local storage provides improved disk read and write performance. The disks are built in a redundant array of independent disks (RAID) configuration for redundancy, disk replacement, and health monitoring that is fully managed by IBM Cloud®. In newer data centers, this storage is all solid-state drive (SSD) to provide the best performance. For more information about available data centers for local SSD storage, see Balanced local storage.
Portable SAN storage
Portable storage volumes are auxiliary storage solutions that are exclusively available on Virtual Servers. The portable SAN is built on IBM Cloud's all Flash Storage clusters rather than the local host storage. This infrastructure provides greater resiliency if a host fails and can also support much larger volumes. If a host fails, virtual server instances that use SAN-based storage are automatically migrated to other hosts and restarted.
Portable storage is an ideal solution if you want to transfer data between virtual servers that exist in any data center on IBM Cloud's network. Portable storage volumes are useful for database applications that require access to raw, unformatted block-level storage and for moving large data sets between Virtual Servers.
Portable SAN storage considerations
- All secondary disks are attached as portable storage. In most cases, these secondary disks can be detached at any time to allow them to be moved to other virtual servers.
- If public virtual servers use balanced local storage, you can't detach primary or secondary disks.
- You can attach the disks to another server if the change doesn't exceed the disk quota or the maximum volume size limit of the targeted virtual server.
- Moved disks are converted to the storage type of the target server.
- When a portable storage volume is attached to a virtual server in a different data center than the original virtual server, IBM Cloud copies the volume to the SAN in the new data center. The system then verifies the integrity of the copied volume and removes the original portable volume from the original data center SAN.
LVM limitations
Logical volume management (LVM) isn't supported as a bootable partitioning scheme. With proper operating system support and configuration, you can use secondary virtual server disks for LVM partitions. However, LVM isn't a supported file system for image templates or flex images.
Supplemental storage
Virtual servers are fully compatible with File Storage for Classic and Block Storage for Classic, and IBM Cloud® Object Storage. These storage types are recommended for cluster drives, shared file storage, archival storage, large storage requirements, or specific performance requirements.
For more information about supplemental storage options, see the following resources:
Next steps
For more information about using portable storage volumes, see the following tasks: