metaSAN Frequently Asked Questions

metaSAN appeals to film and video editors, digital artists, healthcare specialists, and corporate users who have high to heavy bandwidth requirements and want to simultaneously access a common pool of data files such as video clips, databases, satellite imagery, medical archives, or CAD files - as easily and transparently as if the content was stored on their local drive.

metaSAN clients are looking for performance not available over conventional LAN architectures.

metaLAN Server and metaLAN will appeal to video editors, digital artists, healthcare specialists, and corporate users who have low to medium bandwidth requirements and want to simultaneously access a common pool of data files such as video clips, databases, satellite imagery, medical archives, or CAD files - as easily and transparently as if the content was stored on their local drive.

metaLAN Server clients want to benefit from low cost LAN infrastructures but without being limited by some of the limitations associated with traditional servers or NAS appliances.

Refer to the Minimum System Requirements page for an up-to-date list of supported platforms and OS builds.

No. metaLAN does not use any of the Microsoft Client Access Licenses (CAL) and therefore does not limit the number of metaLAN clients that can connect to a Windows XP/Vista/Windows 7 workstation.

metaSAN/metaLAN can significantly increase both the speed, and the reliability of render farms.

Many rendering programs take advantage of memory-mapping techniques to remember where textures and other source material reside on the disk (so they can access the blocklevel chunks they need as opposed to reloading the entire file every time). This memorymapping technique cannot be used when using network file protocols. This is why rendering over a network is often much slower. On the other hand, metaLAN mounts remote drives over the network as “local drives” and enables block-level access. This results in lower LAN traffic and faster access to textures and source files, which ultimately translates into significant speed increases.

In a large render farm - where a SAN is used and multiple servers are put to contribution - one set of render nodes connects to the shared storage via one server while another set of nodes connects through another server. At any given time, it is very likely that one of the servers be over-solicited, while the others are under-solicited. metaSAN/metaLAN will provide the automatic load balancing between the render nodes and any available servers to always optimize data transfers. In addition, metaSAN/metaLAN increases reliability: If one of the servers fails, render nodes don’t lose connection to the shared storage; they simply increase the load on the remaining servers.

Yes, you can use metaSAN in a SAN comprising of only Windows or Mac OS computers. You cannot use metaSAN in homogenous Linux environment as Linux computers can participate in your SAN as members only.

metaSAN is fully transparent and compatible with standard applications, including Adobe Digital Video Collection and Apple Final Cut Pro. In addition, the unique virtualization for Avid feature enables media file sharing and efficient collaboration among multiple users of Avid software.

The only applications known to be incompatible with metaSAN are those that make lowlevel check for specific file system drivers, such as Digidesign Pro Tools.

Tiger Technology software is designed to be fully hardware agnostic. If you have a functional SAN, metaSAN can easily be installed and configured so your workgroup can instantly benefit from its unique advantages. metaSAN supports the leading vendors of storage technology such as ADTX, Atto, Brocade, Ciprico/Huge Systems, IBM, Emulex, LSI, Qlogic, Seagate, and Xyratex.

Yes, with minor limitations: If Avid workstation “A” and Avid workstation “B” both capture clips onto the SAN, all new clips will be stored in the common OMFI MediaFiles/Avid MediaFiles folder and will be immediately available to the workstations that captured them. But despite the fact that the media are stored in a common location, the two databases will remain different. As such, workstation “B” will not automatically see clips captured by workstation “A” (and vice versa). When attempting to open a project - or bin - referring to clips captured on another workstation, the media will appear as offline. The workaround is to manually trigger a refresh of the media directories in Avid. This forces a re-scanning of the OMFI folder that will repopulate the local database with all clips found in the OMFI MediaFiles/Avid MediaFiles folder. This simple operation only needs to be done when new clips have been ingested (or rendered) and needs to be detected on a different machine.

Instead of keeping all projects on one large SAN volume, some users prefer creating multiple volumes to avoid storing too many “unrelated” clips in the same OMFI Mediafile/Avid MediaFiles folder. This is an excellent way to manage larger projects and does not limit the sharing capabilities of your SAN. It does however, force you to plan the size of your volumes.

metaSAN works with Avid Xpress, Media Composer, Adrenaline, Symphony, and even Nitris! metaSAN supports all Avid editing products on the same SAN. metaSAN achieves this by addressing two requirements: by enabling OMFI MediaFiles/Avid MediaFiles folders to be shared by each Avid Xpress, Media Composer, Adrenaline, or Symphony workstations that connect to a specific shared volume, but also by providing the native NTFS file system that Nitris requires to run.

No. This feature is currently only available on Windows platforms. However, you can create multiple volumes, and “assign” one volume for each of your Avid workstations. You will be able to open the same project from any Avid workstation, but you won’t be able to share mediafiles dynamically like you can under Windows.

Because they are most familiar with the various components of your setup, Tiger Technology Resellers provide frontline End User support. Tiger Technology assists its Resellers by telephone, email and can offer on-site support options. Please note that you will be requested to provide your Licensing Server’s Order Name or metaSAN Activation Serial Number in order to validate your support eligibility.

Evaluation licences allow you to test and configure your SAN before purchasing the software. An Evaluation licence is fully functional and can operate for 30 days. Software download and activation is done through the Tiger Technology licensing server. If you already have a functional SAN hardware and want to evaluate metaSAN, you can easily obtain Evaluation licences from your Tiger Technology Reseller.

You can tell if a software release is a major one by looking at the version number. If the version number on the left side of the decimal point has changed, it's a major version. For example, version 4.0 is the current shipping release; the release of version 5.0 would be an example of a major version. Major versions are only available to those covered under the Tiger Technology Subscription Program.

No. Unlike hard zoning, metaSAN soft zoning does not restrict other workstations from seeing the disks. However, soft zoning will prevent users from mounting volumes on workstations that do not participate in the respective SAN definition. Thus, even though the physical backbone of the SAN is one and the same, storage resources and traffic to them are allocated in multiple SAN’s definitions, depending on the needs of the workgroups that will use them.

The San Definition information is propagated across all computers that participate in a SAN Definition. The information is stored in a small text file that resides on the shared storage (on each SAN volume), and is also replicated on the system disk from which metaSAN is started. At any given time each computer in a SAN Definition has the knowledge about the drives and computers that participate in that SAN Definition.

In a Floating Master configuration, the “master” role of a given computer is volatile. The “master” machine will play its role as long as it is up and running. In the case of a failure (or of a forced shut down), failover takes place and the mastership is transferred to another machine. The transfer of mastership occurs after a timeout period during which the other machines in the SAN Definition realize that the Metadata Master is lost and that a new one needs to be elected. The duration of this timeout is set through the Failover Detection setting. While data integrity will be maintained during the failover, a slight delay will be introduced in any transaction that is taking place.

metaSAN supports native NTFS and HFS+ file systems. However, SAN Members do not access these file system through the built-in OS drivers (as the OS does not have SAN capabilities and will corrupt the file system). metaSAN handles the calls locally or redirects them to the Metadata Master. Regardless of the file system it handles, metaSAN/metaLAN complies with all the requirements of the OS for a native file system and therefore can be used safely instead of a "native" volume. This allows HFS+ file systems to be seen as “native” on a Windows platform (and vice-versa), while providing both reading and writing capabilities.  This approach makes metaSAN conceptually different from all types of network sharing protocols that are clearly distinguished by the OS as such.

Using multiple SAN definitions (and Metadata Masters), it is possible to have both HFS+ and NTFS volumes visible from PCs and Mac.

metaSAN keeps metadata overhead to an absolute minimum. The bulk of the metadata traffic occurs when performing lots of very small data transactions. While it is seldomly reported as a problem, Metadata traffic should always be kept on a separate Ethernet switch to ensure optimal performance. Still, metaSAN allows you to slightly reduce the communication over the Ethernet by simply lowering (or eliminating) the failover detection frequency of your SAN. In this case SAN Members will check less often for the availability of a Metadata Master, thus minimally reducing traffic.

Besides Metadata Master Failover, metaSAN implements an additional mechanism for providing SAN Members with uninterrupted access to data on the shared storage. In case there is a failure of the FC HBA or FC cable on a Member machine, the FC to Ethernet Failover mechanism of metaSAN automatically redirects access to files on the shared storage from the Fibre Channel to the LAN and thus Members can continue working on the volumes although with decreased performance.

metaSAN can easily manage multiple volumes. Keep in mind that huge volumes with tons of files are not very efficient. The maximum single volume size that can be managed by metaSAN is the maximum size that can be managed by the OS. It depends on whether the volume is software striped (i.e. dynamic) or not. Using standard partition tables (basic disk), the maximum size under Windows is determined by the sector size reported by the controller. With standard block size of 512 bytes, the largest volume is 2TB (terabytes). But using blocks size of 4196 bytes you can create basic volumes up to 16 TB.

You must use striping if you need to create larger volumes. Windows XP Professional manages dynamic disks in a special database instead of in the partition table, so dynamic disks are not subject to the physical limit imposed by the partition table. In theory, dynamic NTFS volumes can be as large as 256TB.

NOTE: Before using dynamic disks with metaSAN, please read the notes below.

Within any SAN environments, dynamic disks can be difficult to manage because of their nature. Extra care should be taken when using dynamic disks. As such, Tiger Technology recommends the use of basic disks whenever software striping is not required.

According to Microsoft, if you experience an unplanned outage (for example, fabric problems or a power outage) and lose access to the SAN storage that houses the dynamic disks, all dynamic disks will drop offline from the OS at the same time. If there are no dynamic disks attached locally, there are no LDM (Logical Disk Manager) database synchronization issues to contend with when the SAN disks eventually come back online. However, if you have even one dynamic disk on the locally attached storage, you run the risk of the LDM databases being mismatched, and you may have trouble getting one or more SAN-attached dynamic disks back online.

To combat that problem, avoid having dynamic disks locally if you need to have them on the SAN. If you must have dynamic disks in a mixed configuration of both locally attached storage and SAN-attached storage, it is a good idea to protect all fiber hubs, routers, switches, SAN cabinets, and the server from power outages by using uninterruptible power supplies (UPSs) on all connecting devices. Tiger Technology has developed tools to backup and restore (LDM) databases.

metaSAN supports all RAID levels implemented in hardware.

Some limitations apply to software RAID:
metaSAN supports RAID 0 (and RAID 50) striping on Windows and Mac. metaSAN fully supports simple and striped volumes. Spanned volumes are not supported in cross-platform
environments. RAID 1 (mirror) volumes are not supported either.

Although it is possible to span volumes (which allows adding storage to the file system without reformatting), Tiger Technology does not recommend this practice, as expanding a spanned volume is a risky business. The following article from the Microsoft's knowledge base illustrates why: http://support.microsoft.com/default.aspx?scid=kb;en-us;329826

Nevertheless, if you need to perform this operation, the following steps should be executed:

1. Shut down all the machines but one.
2. Enter Maintenance Mode.
3. Backup the current LDM.
4. Expand the volume using Disk Manager (must be of dynamic type).
5. Backup the new LDM.
6. Reboot.
7. Start all machines.

Note that spanning is not supported in cross-platform SAN.
 

Yes. However, in order to adopt computer clustering in metaSAN environment, you should configure the cluster resource disks (such as the quorum disk, for example) to be excluded from metaSAN i.e. not to be managed by metaSAN. To do this on each cluster node you should create a metaSAN registry key for each cluster resource disk you want to exclude from metaSAN. Please contact support for details prior to configuring MSCS with metaSAN.

No. For metaLAN to work there needs to be at least one workstation with direct access to the volumes and metaSAN (metaSAN iSCSI, metaLAN Server) installed and activated to provide LAN clients’ accesses to the SAN.

Yes. You can attach any type of storage (SCSI, SSA, etc.) to your metaSAN data master, if no other computers need to connect directly to the same storage unit. metaSAN is designed to run in solo mode and will be able to serve multiple metaLAN clients. Keep in mind, however, that no failover or load balancing will take place on your LAN network since at least two metaSAN computers are needed to provide this functionality.

Implementing Link Aggregation (aka trunking) is the most effective way to boost performance to LAN clients. Most adapters with multiple Gb ports, as well as most manageable Gb switches, offer support for this feature. Link Aggregation is recommended between the server and the switch. The individual metaLAN clients continue to connect to the switch over regular Gb connections.

"TOE" stands for TCP Offload Engine and refers to an Ethernet NIC and switches that supports TCP/IP protocol processing for data movement, thus offloading the CPU. While TOE support is not required, it provides better performances.

Yes, when creating LAN shares – if you don’t specify a more specific directory of a volume to be exported as a share, the whole volume will be shared to LAN clients.

To avoid excessive burden on any given Data Master, metaLAN ensures that all requests coming from LAN clients are fairly distributed among the available Data Masters.

No, metaLAN allows you to deploy a configuration of Data Masters (SAN Member machines) and LAN clients that use any of the three supported platforms – Mac OS X, Windows and Linux, as long as there is a suitable machine (Mac OS X or Windows) to supervise the volumes.

To avoid data corruption from systems attached to the SAN but onto which metaSAN has not yet been installed, we protect the drive by making it unavailable to the OS. To the user, the access is denied. There are a few circumstances under which this can occur:

• When metaSAN has been installed, but has not yet been activated.
  • Go to the About page and follow the activation procedure

• When accessing the SAN storage from a machine that is not running metaSAN (or after uninstalling metaSAN)
  • If you want to permanently remove metaSAN and free your storage from any protection, you should remove it from any SAN Definition BEFORE uninstalling metaSAN
  • If you have already removed metaSAN from your system, refer to the User’s Guide or contact our support team.

This happens because of a communication problem.

You should NOT try to re-create or import the SAN Definition from another machine as this will create redundant information instead of solving the problem. metaSAN will connect and the volumes will mount automatically as soon as a proper LAN connection can be established with the metadata controller.

Make sure you can ping all the workstations, and make sure there is no firewall preventing communication from taking place.

This can also happen when there are multiple NICs in a system (such as a wireless adapter on a Laptop). In this case, it is important to configure metaSAN/metaLAN to use the proper NIC adapter (refer to the User’s Manual).

Finally, another reason for this problem can be that there is no active Metadata controller (MDC) for the SAN definition. For example, all machines are shutdown and you are installing the last SAN client. The wizard will detect the SAN definition on the disks and will attempt to contact the master. But since the master is shutdown, this attempt to add to the SAN will fail.

If the volume appears as a SAN volume in metaSAN Volume Page, but is not mounting in the desktop, click “Refresh Finder” in the Utilities pages.

It is best to make changes to a SAN definition when all members are up and connected to the SAN to ensure that the information gets broadcasted to all.

One can falsely assume that metaSAN delivers poor performance, when in fact it is the storage unit that doesn’t deliver the same throughput when multiple files are being accessed simultaneously. That’s because the disk’s heads needs to swing from one end of the platter to another (as opposed to performing sequential reading or writing). Performance test utilities such as IOMeter can easily demonstrate this and should therefore be run before installing metaSAN and connecting multiple machines to the SAN. For high-performance SAN, specialized storage is often chosen that includes special mechanism designed to better handle simultaneous accesses. This explains why storage pricing can vary greatly for apparently similar performance and capacity. Your Tiger Technology Reseller will assist you in choosing the right storage.

The recycle bin is disabled intentionally on SAN volumes. The reason is that a separate recycle bin is created for each user. User Administrator for machine A and machine B are different users (they have different user IDs) and separate recycle bins are created. If recycle bin is enabled, it may be impossible to identify where your free space on disk has gone. For example, when you log in with user A on machine A you can permanently delete all files from the disk. Your recycle bin is empty and you do not see any files in it. However, if other users used the recycle bin, you will not see these files. But you will notice that even if there are no files on the disk, you will not have the entire capacity of the disk. In this was the case, the user would think that the file system is corrupted and that metaSAN has eaten the free space!

You can’t run Check Disk or Defrag software safely on a SAN volume as multiple machines can read & write to it while the file system is being updated. It is therefore necessary to first Disconnect all members from the SAN volume (SAN Management/Volumes…/Disconnect all), then mount the volume as Private (SAN Management/Volumes…/Private) on one machine. You can then run the software safely. Reconnect all members when done (SAN Management/Volumes…/Reconnect all). If corruption is found, the volume must be unprotected before it can be repaired. This is done by removing the volume from the SAN Definition when all but one computer is connected to it. Volume needs to be added back into the SAN definition when corruption was fixed, and before booting remaining members.