Migrating Virtual Machines to 512e Storage
everRun Release 7.8.0.0 or higher includes support for presenting volumes to the guest operating systems as the 512e disk type. If there are 512e disk drives in both physical machines (PMs) of an everRun system, and the applications running in the virtual machines (VMs) could benefit from 512e drive performance, it might be possible to reconfigure the system to take advantage of the 512e drives.
When you upgrade to everRun Release 7.8.0.0 or higher, existing storage groups are not automatically reconfigured for 512e support, and they cannot be reconfigured in place; however, it might be possible to assign new or unused 512e drives to a new 512e storage group to make a pool of 512e storage available for the VMs to use, as follows:
- If your system has empty disk slots, insert additional 512e disk drives, create storage groups for data with the 512e disk type, and allocate the storage as described in this topic under To migrate compatible systems to 512e storage.
- If your system has no empty disk slots for additional 512e drives, run the 512e compatibility script to determine if the system has unused 512e disk drives that you can assign to new 512e storage groups, or if you would need to rebuild the everRun system to free up 512e disk drives. You can run the script as described in this topic under To determine system compatibility for migration to 512e storage.
If you cannot add new 512e disk drives, and the system has no unused 512e drives (for example, if it has 512e drives that are currently in use by 512n storage groups), it might be possible to rebuild the everRun system to free up 512e drives, but the rebuild procedure is time consuming and involves significant downtime. If applicable, see KB0014930.
To determine system compatibility for migration to 512e storage
After upgrading an everRun system to Release 7.8.0.0 or higher, you can run a compatibility script to determine if the system has any unused 512e drives or drives that can be reconfigured with a system rebuild:
- Before running the script, activate all new or foreign drives in both PMs, as described in Activating a New Logical Disk.
- Log on to the host operating system of each PM in the everRun system as the root user. (For details, see Accessing the Host Operating System.)
-
Run the compatibility script in the host operating system of each PM:
# /opt/ft/sbin/find_available_512e_drives - Examine and compare the output.
For example, if migration is possible now with unused 512e drives, the output is similar to the following:
512e drives in this system:
/dev/sdb ('Logical Disk - 1')
512e drives that can be moved to a 512e storage group now:
/dev/sdb ('Logical Disk - 1')
If migration is possible only with a system rebuild, the output is similar to the following:
512e drives in this system:
/dev/sdb ('Logical Disk - 1')
No 512e drives can be moved to a 512e storage group now
512e drives that can be moved to a 512e storage group with a system rebuild:
/dev/sdb ('Logical Disk - 1')
Compare the output from both PMs and determine the next steps:
- If both PMs have unused 512e disk drives that you can use without rebuilding the system, then create a new 512e storage group, assign the drives to the storage group, and copy or move the VMs to the storage group as described in this topic under To migrate compatible systems to 512e storage.
- If the only way to make 512e disk drives available is to rebuild the everRun system, then refer to KB0014930.
To migrate compatible systems to 512e storage
If your everRun system contains new or unused 512e disk drives, and the compatibility script confirms that you can move these drives to a 512e storage group now without a system rebuild, use the following steps to migrate your VMs to 512e storage:
- Back up the VMs.
- For Windows-based guest operating systems only, if you have not already done so, download and update the VirtIO drivers as described in Updating the VirtIO Drivers (Windows-based VMs). At a minimum, you must update the storage drivers to support 512e volumes.
- Create new, empty storage group(s) with the 512e disk type, as described in Creating a New Storage Group.
- Assign the new logical disk(s) (paired physical disk drives) to the storage group(s) that you created, as described in Assigning a Logical Disk to a Storage Group.
- Create new VMs in the new 512e storage group(s), as described in Creating a New Virtual Machine, or move existing VMs from the current storage groups by doing one of the following:
- Copy existing VMs to the new 512e storage group(s), as described in Copying a Virtual Machine. (If your system lacks the disk space to copy the VMs, try the next option.)
- Export existing VMs as described in Exporting a Virtual Machine, and then import them to the new 512e storage group(s) as described in Importing an OVF or OVA File.