Frequently Asked Questions

Q-1) What is PetaShare?
PetaShare, basically, is an infrastructure that lets users to access distributed storage resources easilly.

Q-2) How can I install PetaShare?
PetaShare itself is not a software that you can install as a user. Instead you can install one of the client tools available to access Petashare infrastructure.

Q-3) So, what are these client tools and why there are more than one?
At the time of being the following client tools are available:

The reason that there are more than one client tool is that the system environments of users may diverse drastically, such as OS, kernels, machine architecture, etc as well as functionalities that are needed by users and applications. So, the heterogeneity of environment makes it hard to provide a single and unique tool to access petashare.

Q-4) What is PetaFs and how does it work?
PetaFs is a FUSE based userspace filesystem interface for PetaShare. It allows you to mount PetaShare resources to the local filesystem hierarchy. After mounting PetaShare resources to the existing hierarchy, the data in PetaShare resources can be accessed as conveniently as the ones that are in local filesystem. The important thing for PetaFs is that, its installation requires kernel support for FUSE.The kernel versions equal or recent than 2.6.14 have already FUSE support. So, be sure that your current kernel is upto date, or at least FUSE support has been enabled.

Q-5) What is Petashell and how does it work?
Petashell is a interactive shell interface that enables to access PetaShare resources. Through Petashell shell window, all PetaShare resources can be accessed with basic posix commands. What Petashell does is it captures I/O calls made by an application for PetaShare resources within the shell and connects corresponding PetaShare resources and manipulate I/O operations on those resources. PetaShell is an alternative client tool in the case of users' system does not have FUSE support to install PetaFs client tool.

Q-6) What is PCommands and how does it work?
PCommands is a set of unix-like commands that provides users with capability of accessing PetaShare resources, managing these resources and metadata of files. These commands have advance options that enable easier access and more control for basic batch data movement operations. PCommands is preferred by users who need metadata insertion capability and use PetaShare resources as secondary data repository, instead of first level data resources for applications.

Q-7) I am a linux/unix user, which client tool should I use?
If you will use PetaShare resources as data source for your applications, it is convenient to use PetaFs. However, as we mentioned before, PetaFs requires FUSE support in kernel, so be sure your system already has FUSE support. If not, you can use Petashell instead.

On the other hand, if you will use PetaShare as a secondary storage or archival, it is convenient to use PCommands. It has basic commands like 'pput', 'pget' for data uploading and downloading to/from PetaShare resources. It also provides metadata management utility through 'pmeta' command that many users may want to use. Basically, PCommands is more appropriate for batch data operations and management purposes.

Q-8) I am a Mac OS user, which client tool should I use?
At the time of being, we encourage users to use PCommands in Mac OS. We will provide a Mac version of PetaFs very soon...

Q-9) I am trying to connect PetaShare; however, I can not. What is wrong?
Probably, you are trying to access PetaShare outside of the LONI campuses. You can access PetaShare through LONI network. As you may know, LONI resources can not be accessed directly through traditional T1 internet connection. Please, try to access PetaShare through the network of your campus... If you are already in LONI network(i.e. network of LONI member instituion) and can not connect PetaShare, probably the PetaShare site that you are trying to access is offline... Please, send an e-mail to for further connection problems...


Please feel free to send your questions/comments regarding PetaShare to