Nas Volume - Fujitsu ETERNUS DX S5 Series Design Manual

4. NAS Functions
NAS System (NAS Volume Management)

NAS Volume

TPVs that are used as NAS volumes must be created in a TPP virtual pool. Because TPVs support virtualization of
volume capacity, a volume can be used more efficiently by using a volume capacity that is larger than the actual
physical capacity.
Two types of NAS volumes are available; NAS user volumes used for operation and NAS backup volumes used for
backup.
SAN volumes and NAS volumes can exist in the same TPP. Although NAS user volumes and NAS backup volumes
can also exist in the same TPP, creating these types of volumes in separate TPPs is recommended to ensure
redundancy. For load balancing, it is also recommended to configure a TPP with two or more RAID groups if NAS
volumes will be created in this TPP.
Stop access to all the volumes while a NAS volume expansion is being performed (or while the "expand volume"
command is running). If access is not stopped to the volumes that are not expanded, the volume expansion
process may fail (timeout).
Caution
During the configuration phase
• Do not format the NAS volume. If it was formatted, delete the NAS volume and create it again.
• Do not configure the QoS setting to NAS volumes.
• Do not perform TPV/FTV capacity optimization (Zero Reclamation) for NAS user volumes, NAS backup
volumes, or the system volumes.
• When creating multiple NAS volumes in a Thin Provisioning Pool that is configured with Nearline SAS
disks, create each NAS volume one by one. Wait at least 10 minutes after each NAS volume is created
before creating the next one.
During the operation phase
• An error occurs when a volume capacity expansion is performed with backup and Snapshot settings
already configured. Delete the backup and Snapshot settings before performing a volume capacity
expansion. Do not delete the backup volume at this point because the volume is necessary for
restoration if the volume capacity expansion fails and data on the drive is corrupted. Delete the backup
volume and reset the backup and Snapshot after volume capacity expansion is completed successfully.
• When the NAS volume is being reconfigured (format conversion), do not access the volume with CIFS,
mount the volume to NFS, or access the volume with NFS from the client. If these operations are
performed, an I/O error will occur because the volume is unmounted during the reconfiguration process.
Because the file lock state is released for all file systems, execute the NAS volume reconfiguration
(format conversion) after stopping operations for all file systems.
• For NAS volumes where a NAS volume reconfiguration (format conversion) was performed or for newly
created NAS volumes, do not restore backup data that was acquired before the reconfiguration. Acquire
backup data after reconfiguring the NAS volumes.
• If NAS user volumes and NAS backup volumes are mounted from a UNIX/Linux client, do not run the
following functions on them.
- Volume deletion
- Volume formatting
Note
During the configuration phase
The threshold can be set for TPVs for NAS in the same way as TPVs for SAN.
During the operation phase
A NAS volume reconfiguration (format conversion) takes up to 15 minutes.
166 Design Guide