Twin Studies

Simple or Detailed

In both Nexenta variants, you can set up quotas (but with Netgear, only per-share, not per-user) or reserve a certain minimum size for a share. The Nexenta Community Edition offers more granular settings. Only here, can you set a record size for the filesystem, adjust case sensitivity, stipulate different modes of inheritance for ACLs, or specify whether a disk pool should use a separate log device in synchronous operation in the interest of low latency (which can improve the throughput). Moreover, only the Community Edition supports user quotas and WebDAV or Rsync as access methods to a shared volume. Netgear does not support these features (see Tables 1 and 2).

Protocols and Services

Both candidates support the traditional CIFS (SMB), NFS (each including version 4), FTP, and iSCSI storage protocols. With the Nexenta Community Edition, Mac users remain sidelined; only the device from Netgear supports the Apple Filing Protocol (AFP).

Under NexentaStor and on ReadyDATAOS, you also can configure specific services. In the Community Edition of NexentaStor, the services are:

• Auto-tier, which uses rsync to generate a copy of a volume on local or remote disk as a disk-to-disk backup. Snapshots are also suitable as a source.
• Auto-snap, which periodically creates snapshots of a folder or volume.
• Auto-scrub, which periodically verifies the consistency of volumes on the basis of ZFS checksums.

The Enterprise Edition, which I did not test, also supports other services, including continuously updated snapshots on remote disks (auto-sync) and real-time replication between two NexentaStor appliances (auto-CDP).

The Netgear system already includes replication; you just need to enable the feature. It then provides access to an online portal and configures a secure peer-to-peer connection between the participating ReadyNAS systems, which – thanks to a patented NAT traversal technology – gives the impression that both storage devices are on the same subnet. Port forwarding and Dynamic DNS are not necessary for this setup. You can then choose between scheduled replication (periodic replication) and an activity-driven version (continuous replication). Activity-driven replication is more secure because it activates immediately after changes, without waiting for a specified time interval to expire. Both replication modes are available at system or volume level.

Of course, the Netgear system also has the ability to create snapshots  – both manually and automatically  – with a predetermined frequency.

Users and Rights

Setting up local users might seem like déjà vu. Again, Netgear's ReadyDATAOS is a little faster and easier, but Nexenta's Community Edition is more granular. In the first case, the username, password, email address, and primary group are already set up; in the second case, you can fine-tune the actions the user is permitted on disks, volumes, and shares. Thus, in principle, you can implement role-based concepts that would make it impossible, for example, for the Samba admin to edit the iSCSI resources.

Both products can also integrate users from Active Directory. However, only NexentaStor can handle LDAP. It supports a variety of LDAP servers, including OpenLDAP, Apache DS, Red Hat 389, and Oracle Directory Services.