Linux

CalSoft has expertise in Linux based development and consulting work focused on operating system, kernel, device drivers, file systems etc. We have successfully executed many projects for leading Fortune 500 technology companies in this area. 
 
Our expertise in the development of linux based projects is shown below:

Monster File System: a NAS Aggregation product 
The Monster File System was a Cluster File System that allowed unmodified NFS clients and also customized MFS clients to access a global file system that could support anywhere from 256 nodes upwards. This involved a lot of interesting research, especially in the area of scalability and distributed system design. We designed and implemented this system on FreeBSD and Linux.

xNFS
xNFS is a network file system based on NFS that allows the client machines to take full advantage of the performance and scalability benefits of SANs. Access to the meta-data is still coordinated by file servers, but clients access the SAN directly for data-intensive operations (reads and writes). xNFS is designed as an extension of and is backward compatible with traditional network file systems, such as NFS and CIFS. We followed the approach of stackable file systems and therefore it is independent of the underlying physical file system. It is portable to any operating system that supports the vnode (VFS) interface. xNFS performance matches that of the local file system Ext2 on Linux.

Device driver that simulates Fiber channel over Ethernet
The purpose of the SCSI/FC Test Suite was to ensure that the SCSI, Fiber channel and Block virtualization functions of a storage switch or a storage box were well tested. The test suite was shielded from the changes in communication protocol by making it SCSI specification compliant. In the initial stages of product development the switch maker was using raw Ethernet frames. CalSoft developed a pseudo FC HBA adapter that spoke Fiber channel protocol over Ethernet. A SCSI HBA driver that communicated to the SAN switch using FCP over Ethernet was written. This driver had the dual purpose of ensuring that the SCSI Tester framework would remain protected in case of any protocols changes, and of emulating some of the hardware functionality in the early stages.

Network Abstraction Layer for a TOE card for Lustre
Lustre is a cluster file system initiative supported by the US Department of Defense and the US national defense labs to manage huge data. Lustre will run over many different networks and the cluster file system has a specific network access API for each network type. CalSoft has designed and implemented a network abstraction layer for Lustre, a cluster file system over Alacritech's TOE card.

NextGenNAS (Next Generation NAS)
This is CalSoft's component. The objective of this component is to unify disparate storage boxes running NFS into a single namespace, provide scalability of metadata services by implementing flexible and scalable polices with respect to the number of Intermediate servers that manage the unified namespace, provide striping support across multiple Partition servers (basically NFS servers which can be used as storage repositories) and hence improve performance, provide powerful locking semantics and guarantee a level of consistency of data that is both reasonable and acceptable with regard to the performance penalty incurred thereby.

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