Cross-Platform Recovery File System Layer
Cross-platform recovery file system layer (XPRFS) is a special implementation of a virtual file system layer. It is an advanced restore feature that allows for mount and restore onto different operating systems and hardware platforms (Windows – MTF <–> Linux/Unix – cpio).
For example, data backed up from a Linux system (cpio saveset) can be mounted on Windows RDS, and data backed up from a Windows system (MTF saveset) can be mounted on Linux/Unix RDS; note that the operating system of the restore target must be the same as the operating system of the used Remote Device Server (RDS) (for details, see Restrictions below).
XPRFS employs direct access to backed up data and allows you to access individual backed up files through a file browser, thus enabling single file restore. However, the original ownership and access settings for restored objects are not preserved when the backup is mounted; the user under which the SEP sesam service is running is effectively the owner of the restored files. For details, see Restrictions below.
XPRFS requires the following:
- A SEP sesam data store Path or SEP sesam Si3 data store is required for instant single item recovery.
One of the XPRFS main advantages is that it is no longer required to perform a complete restore of backed up data. By selecting the Mount saveset option in the restore wizard, the target saveset is mounted to the SEP sesam home directory var\tmp\mnt, e.g., C:\Program Files\SEPsesam\var\tmp\mnt\saveset_ID. The mounted saveset is instantly accessible for browsing and searching (some limitations apply, see Restrictions below).
It is recommended to use the XPRFS for restoring specific data, such as Exchange, Hyper-V (check Hyper-V restrictions) and V-Sphere backups with the following major advantages:
- Instant access to your data, such as single mailboxes.
- Faster restore time and performance.
- Reduced free space requirement on restore target.
- Protection of mounted data – all data is mounted read-only, allowing you to query the saveset and preventing you from altering or damaging the data content.
XPRFS general restrictions
The following restrictions apply for mounting and cross-platform recovery:
- Note that mounting does not preserve the original ownership and permissions for restored objects. The owner of the mounted backup/restored data is determined by the user under which the SEP sesam service runs. Typically, on Unix/Linux this is root, while on Windows the sesam service is typically running under the LocalService account (NT AUTHORITY\LocalService; system user). Note, however, that some SEP sesam extensions (such as Exchange Recovery Pro or SharePoint Recovery Pro) require that the SEP sesam service is configured with a user account with domain administrator privileges.
- You can mount a Windows backup to a Linux system or a Linux backup to a Windows system, but the operating system of both, the Remote Device Server (RDS) you used for mounting and of the destination restore target must be the same. For example, you can mount a Windows backup on the Linux device server, but this backup can be restored on Linux host only and vice versa: you can mount a Linux backup on the Windows device server, but this backup can then be restored on Windows host only.
- When performing a cross-platform restore, you should be aware of the data characteristics related to different platforms. For example, if you are restoring Windows data with access control list (ACL) (or alternate data streams (ADS)) to Linux, you have to be aware that ACL (and ADS) will not be preserved. Be aware that certain limitations apply whenever data is restored to another environment.
- Restore with Exchange Recovery Pro and SharePoint Recovery Pro is using the XPRFS feature too, therefore the same requirements apply. Note that Exchange Recovery Pro mounts the target saveset by default, so the option Mount saveset must not be selected. For details, see Exchange Recovery Pro or SharePoint Recovery Pro.
Additional restrictions apply for mounting and single file restore on Hyper-V:
- You can only perform single file restore on a Windows Server/RDS since you need the PowerShell in order to execute it.
- You can only mount Windows VMs due to the underlying file system.
Once you are aware of the restrictions and ensure that prerequisites are met, you can enable XPRFS: From the SEP sesam GUI menu bar select Activities -> Restore -> select saveset -> select task -> under Single file restore select Mount saveset. For details, see Standard Restore Procedure.