Sirix is a versioned tree-based storage system. It provides Snapshot Isolation through MVCC and is best suited for flash-based storage. The tree encoding is suited for heavy update operations. It provides diffing algorithms either to import diffs between currently shredded (imported) XML documents to update a tree structure or to get the differences between versions of a tree structure. A GUI provides several visualizations for comparing imported tree structures.
btier is a Linux kernel module that creates an auto tiering block device. It can be used to aggregate various types of storage into a virtual block device. btier will automatically optimize data placement on the underlying devices according to a policy that can be set. The size of a btier device is equal to the combined size of all block devices that were assigned to it. Only a small amount of space is used to store the metadata of the device. A btier device can contain up to 16 physical devices or files. Next to the built-in data migration engine, btier also provides an user space API the allows user to write custom data migration engines. Python, C, and bash example code is included. btier can use raw devices or (sparse) files (even hard mounted NFS) as part of the tiering device. The last tier can therefore reside on a deduplicating or compressing filesystem when needed. The devices that are used with btier should be redundant, since a btier device will lose all data when one of the underlying devices is lost. The performance of btier is determined by the devices that are used for the first tier. It is known to scale up to 130k IOPS with a RAID1 that consisted of modern PCIe SSD's. btier has support for SSD trim / discard, and can be configured in writeback or writethrough mode.
io-util is a small, scalable Java library for slicing and dicing fixed width tables on disk. The objective is to provide reusable blocks of code for building efficient, custom binary data stores. It allows you to build, search, and maintain a large, externally stored, fixed width, sorted table. The library user specifies the row width (in bytes), a row comparison function (which implicitly defines any given row's key), and an optional delete codec.
piler is an email archiving application with all the features required for an average company. The most prominent features are full text searching, deduplication, compression, encryption, digital fingerprinting, policy rules, access control, a built-in SMTP server, and Active Directory/openldap support.
KVZone is an evaluation tool for comparing performance of key-value stores. It provides various configuration parameters to match the expected application workload. It provides adapters for existing key value stores such as TokyoCabinet and simple databases such as sqlite3 and BerkeleyDB that can be used as key-value stores. New adapters can easily be written to evaluate other key-value stores.
Kvpm is a GUI front end for Linux LVM and GNU parted. LVM2 groups and volumes can be created, removed, and manipulated using most of the options supported by the standard LVM2 tools. Some support for creating and operating on partitions is provided. It also handles creating and mounting filesystems. LVM version 2.02.88 or newer must be installed with the lvm2app library. Only the KDE 4 libraries need to be installed, not the entire desktop, so it my be run from within Gnome, for instance.