Core FS¶

The Core Filesystem (/asap3/<facility|research group>/gpfs) is accessible via several methods. Accessing the Core filesystem is only possible from within the DESY network (guest network and eduroam are external) and always requires a valid DESY account.

Access Methods¶

Native GPFS - via Maxwell¶

The Core filesystem is mounted on the Maxwell Analysis cluster. This is the fastest available solution for accessing the Core filesystem. For more information about resources for Photon Science in Maxwell, check Maxwell for Photon Science

SMB - For Windows, macOS and Linux users¶

For Windows, macOS and Linux users from Office networks, SMB is the recommended way to access the Core filesystem.

Linux desktop users should also access the Core filesystem via SMB, as it does not require any root permissions or configuration on the clients. This is currently the only way to mount the Core filesystem on a DESY green desktop installation.

Each individual facility or research group has its own share:

Mapping a network drive¶

NFSv4 - For Linux users¶

While SMB is still the recommended way to access the Core filesystem, certain use-cases require an NFS mount.

For this purpose, an NFSv4 export with and without Kerberos is available.

For some research groups there is no nfs export configured yet. If that is needed contact asap3 request queue.

The groups without export are:

Restricted Mount Access¶

Access to the NFSv4 exports are either restricted by IP subnet or netgroups from LDAP.

For PETRA III and Special Instruments, the mount is only allowed from specific subnets:

For FLASH, hosts in the LDAP netgroup a3-flash-core-krb5-hosts are allowed to mount the core filesystem. To display the hosts, you can use ldapsearch on pal.desy.de: ldapsearch -x cn=a3-flash-core-krb5-hosts

For FS-FLASH-O, hosts in the LDAP netgroup a3-fs-flash-o-core-krb5-hosts are allowed to mount the core filesystem. To display the hosts, you can use ldapsearch on pal.desy.de: ldapsearch -x cn=a3-fs-flash-o-core-krb5-hosts

For FS-FLASH-B, hosts in the LDAP netgroup a3-fs-flash-b-core-krb5-hosts are allowed to mount the core filesystem. To display the hosts, you can use ldapsearch on pal.desy.de: ldapsearch -x cn=a3-fs-flash-b-core-krb5-hosts

For FS-BMX, hosts in the LDAP netgroup a3-fs-bmx-core-krb5-hosts are allowed to mount the core filesystem. To display the hosts, you can use ldapsearch on pal.desy.de: ldapsearch -x cn=a3-fs-bmx-core-krb5-hosts

Mounting via NFSv4 with Kerberos¶

Mounting the Core filesystem via Kerberos requires root privileges on the client machine.

mount -o nfsvers=4,sec=krb5,hard <NFS Export> <local mountpoint>

Additional configuration and a kerberos keytab is required on the client machine, the setup for this is out of scope for this documentation.

Due to the nature of Kerberos, access is only possible while you have a valid kerberos ticket. The ticket lifetime is usually limited to 24h. Afterwards, the ticket has to be renewed in order to access the data. This is usually ok, but cumbersome for long running, non-interactive processes.

Mounting via NFSv4 without Kerberos¶

Mounting the Core filesystem without Kerberos requires root privileges. Due to the security implications for this type of mount, this must be explicitly requested, as the host will be included in a whitelist. Please contact FS-EC in order to be included in the whitelist.

mount -o nfsvers=4,sec=sys,hard <NFS Export> <local mountpoint>

Additional configuration is required on the client machine, the setup for this is out of scope for this documentation.