In an IT context, LVM stands for the logical volume manager. The Logical Volume Manager is a block device subsystem of Linux that is placed between the filesystem and the physical disks. The LVM serves as a translation layer that permits advanced operations, including the snapshot feature for SQL database backup, and is fully transparent to the filesystem.
Logical volume management is designed to offer a higher-level view of disk storage compared to the traditional view of disks and partitions.
For those servers that can support LVM, the Snapshot feature in LVM is extremely useful as it enables you to get a specific point-in-time backup with minimal table locking.
Despite its utility, many businesses today are discovering that the native Snapshot utility available in Linux’s LVM doesn’t give them all the flexibility and functionality they need.
Linux Hot Copy
Idera’s free Linux Hot Copy disk snapshot utility picks up where LVM Snapshot leaves off. Linux Hot Copy addresses the two key limitation of LVM:
- The LVM Snapshot feature can become problematic when multiple Snapshots are required — Linux Hot Copy eliminates the multiple snapshot limitations of LVM as there is no upper limit on the size of a read/write Snapshot. Moreover, Linux Hot Copy versions 3.3.0 or later are optimized for performance so you can create and store multiple Snapshots of the same device or volume to save multiple recovery points.
- There must be sufficient space on the LVM volume to support a Snapshot — Linux Hot Copy is simpler and easier to use as it can use free space on any existing file systems. This means DBAS can create file systems and place snapshots on less expensive disk tiers than those for the production application.
Idera’s Linux Hot Copies are both readable and writable. This vastly increases the flexibility for use in system administration, meaning you can test scripts and new appss on your data rather than actually running them live.
Snapshot technology has become an essential part of the backup strategy in most enterprise environments today. By the same token, more and more DBAs are realizing that the native LVM Snapshot utility is inadequate for their needs, and the solution is a thoughtfully designed third-party solution such as Idera’s Linux Hot Copy.