PLANET UMG-2000 - Manual (Page 48)

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7. Web Management - Storage
The UMG-2000 Series storage suite includes the following services: Redundant Array of
Independent Disks (RAID), Network Storage Server, backup/restore, and remote data
synchronizing.
RAID AND JBOD
The UMG-2000 Series supports RAID on storage devices. A RAID device is a logical device
that has physical devices underlying it. These physical devices are disk partitions. The
supported RAID levels are:
Level 0:
Provides data striping, or the spreading out of blocks of each file across
multiple disk drives but without redundancy. This improves performance
but does not deliver fault tolerance. If one drive fails then all data in the
array is lost.
Level 0+1:
RAID 0+1 is a mirrored configuration of two striped sets. This is a technique in
which data is written to two duplicate disks simultaneously, providing data
redundancy.
Level 5:
Provides data striping and utilizes one disk for backup information, which
enables it to restore any other disk in the array.
On top of the RAID, the UMG-2000 Series supports Logical Volume Management (LVM2)
that provides a higher-level view of the disk storage on a computer system than the
traditional view of disks and partitions. This gives the system administrator much more
flexibility in allocating storage to applications and users. Storage volumes created under the
control of the LVM can be resized and relocated. The LVM also allows management of
storage volumes in user defined groups, allowing the system administrator to deal with
sensibly named volume groups.
Another choice other than RAID is the technology of “Just a Bunch Of Disks” (JBOD). The
RAID system stores the same data redundantly on multiple disks that nevertheless appear
to the operating system as a single disk. Although, JBOD also makes the disks appear to
be a single one, it accomplishes that by combining the drives into one larger logical disk.
JBOD doesn’t deliver any advantages over using separate disks independently and doesn’t
provide any of the fault tolerance or performance benefits of RAID.
NETWORK STORAGE SERVER
The UMG-2000 Series supports Server Message Block (SMB), also known as Common
Internet File System (CIFS) to share files on the private network which can be used for
WINDOWS, Linux/Unix and other operating systems and Network File System (NFS)
clients/servers.
BACKUP AND RESTORE
The UMG-2000 Series will automatically backup storage according to the scheduled time.
The administrator can also backup the current storage manually. The UMG-2000 Series
supports two solutions for backup. One is snapshot and the other is full data copy.
Snapshot is an effectual and space-saving method. It is a picture in time of how the data