CAD Best Practices

Overview

CAD (Computer-Aided Drawing or Design) software utilizes databases and other design and planning files that users collaborate on for architecture, engineering, and construction (AEC) activities. Nasuni, powered by the UniFS^® object storage-based global file system, enables CAD files to be stored, protected, synchronized, and collaborated on across locations with greater performance and efficiency than ever before, while also minimizing IT cost and complexity.

To enable users in multiple locations to collaborate on CAD files more efficiently across sites, Nasuni Global File Lock™ can be used. This premium Nasuni feature extends file locking — a file system feature traditionally provided on a single NAS device or file server in one location — across a network to prevent conflicts when two or more users attempt to change the same file on different Nasuni Edge Appliances. If Global File Lock is enabled for a directory and its descendants, any file in that directory or its descendants can only be changed by one user at a time. Other users cannot change the same file at the same time.

This document describes how to configure Nasuni and CAD software such as Autodesk AutoCAD, Bentley MicroStation GeoPak, and Esri ArcGIS to utilize Nasuni’s global file system. Nasuni caches files locally from cloud storage for high-performance access and provides high-speed file synchronization and global file locking for efficient multi-site collaboration. By following this guide, CAD users dispersed across multiple regions should be able to collaborate on CAD files with faster open and save times and less risk of version conflict.

Nasuni Global File Lock

The purpose of Global File Lock is to help ensure that two different users do not simultaneously change the same file. This is valuable in environments where users collaborate on the same set of files. Global File Lock is often enabled on AEC client project folders.

Each time a user opens a file, the Nasuni Edge Appliance sends information to Nasuni’s redundant, high-performance, cloud-based global lock server, which checks to see if the file is already locked for use by another user. This process typically takes less than one second.

Global File Lock ensures that only one user has a file open at a time, regardless of which Edge Appliance or office they are connected to.

Several locking modes are available with Global File Lock.

• Optimized: All locks are elevated to write locks that allow readability. Only one Nasuni Edge Appliance can have a lock on a file at a given time. Optimized locking is supported with both CIFS (SMB) and NFS and is recommended for most applications that don’t rely heavily on shared access modes. Optimized locking gives the best performance but lower protocol compatibility.

Note: NFS volumes only support Optimized mode-locking.

• Advanced: Multiple Nasuni Edge Appliances can hold locks on a file at a given time based on the share access modes. Advanced locking is supported with CIFS (SMB) only. Advanced locking is recommended for applications that rely on shared access modes. Advanced locking provides the highest global locking compatibility but might impact performance.

For suggested Global File Lock modes, see Appendix: Recommended modes of GFL on page 12.

Oplocks and Global File Lock Advanced mode

An oplock (opportunistic lock) is a lock placed by a client on a file residing on a server. Usually, a client requests an oplock so that the client can cache data locally.

Oplocks enable file server clients (such as those using the SMB2 and SMB3 protocols) to dynamically alter the buffering for a given file or stream to increase performance and reduce network use. To increase the network performance for remote file operations, a client can buffer file data locally, which reduces or eliminates the need to send and receive network packets.

For details about oplocks, see Using oplocks for network redirector performance.

With the Advanced mode of Global File Lock, oplocks are automatically enabled for a share. Oplocks allow file server clients to increase performance and reduce network use.

Tip: To use Global File Lock, Global Locking must be enabled in the customer license.

Tip: When using the Advanced mode, oplocks are enabled by default.

CAD and Nasuni Best Practices

To ensure an acceptable user experience when using Nasuni for multi-site CAD collaboration, it is important to understand the factors that can impact file open and synchronization performance:

• Bandwidth

• Latency to the Nasuni cloud-based lock server

• Number of simultaneous users working on CAD files or databases

• CAD use cases (such as if CAD software also manages file access)

Here are some general recommendations to optimize CAD collaboration and ensure a good user experience based on Nasuni’s internal testing and customers’ successful production deployments of Nasuni and CAD software.

Bandwidth and QoS (Quality of Service)

Bandwidth is a significant factor in ensuring an acceptable user experience with CAD software and Nasuni. If QoS is too low, the connection facilitates other traffic, or there is a high number of simultaneous CAD users, the user experience might be impacted.

While the more bandwidth you allocate, the better the user experience, the following chart displays the minimum and recommended bandwidths for both the Optimized and Advanced modes of Global File Lock.

Note: Bandwidth values represent bandwidth available to Nasuni, not overall bandwidth amounts.

Tip: Reducing latency or minimizing the number of simultaneous saves can help mitigate issues caused by lower QoS.

Latency

Network latency is another factor in ensuring a good user experience when using Nasuni with CAD software across multiple sites. The time it takes for each Nasuni Edge Appliance to communicate with the cloud-based lock server that coordinates Nasuni Global File Lock technology can impact CAD operations.

For optimal performance, you should identify the sites with the greatest latency, then consider factors such as:

• How is your Internet traffic being routed? Does it go through a central hub, or can it be routed directly from each site with a Nasuni Edge Appliance?

• Are there any devices on your network that are inspecting traffic, which slows down the flow of packets?

• Are there any devices on your network that are saturated, such as an undersized firewall, that are slowing down the flow of packets?

After you have optimized your internal network to minimize latency, you can measure the latency to the Global File Lock lock server. Test the network latency to the lock server you are using by pinging one of the following:

• globallock-frankfurt.api.nasuni.com (Frankfurt, Germany)

• globallock-ireland.api.nasuni.com (Ireland)

• globallock-oregon.api.nasuni.com (Oregon, USA)

• globallock-sydney.api.nasuni.com (Sydney, Australia)

• globallock-singapore.api.nasuni.com (Singapore)

• globallock-virginia.api.nasuni.com (Virginia, USA)

All GFL lock server systems are redundant. The relationships between the redundant systems are:

• Ireland and Frankfurt

• Sydney and Singapore

• Virginia and Oregon

Select the Global File Lock lock server for each volume that best matches the use case in question. In many cases, the Global File Lock lock server with the lowest latency for the volume is the preferred one.

Increasing bandwidth can help mitigate issues caused by higher latencies.

Number of simultaneous users

There is no hard limit to the total number of users or the number of simultaneous users that can be active when CAD software is used with Nasuni Global File Lock. However, the user experience might be impacted by adding more concurrent users. Increasing available bandwidth (QoS), reducing latency, and minimizing simultaneous saves can help ensure a good user experience as more simultaneous users are added.

Details of CAD use cases

Here are specific suggestions for certain CAD software products.

Autodesk Civil 3D

Slowdown due to .lsp routine

If experiencing unexpectedly long waits when opening projects, the slowdown might be due to a .lsp routine that runs as part of a custom profile. To troubleshoot long open times and rule out customer-specific configurations as the source of the poor performance, you can either revert to an existing default profile or create a new profile with default settings.

To create a factory default profile, follow these steps:

1. Click the application button in the upper right-hand corner.

2. At the bottom of the application menu, click Options.

3. In the Options window, click the Profiles tab.

4. To create a new profile with the contents of the current profile, click Add Profile. This brings up the Add Profile window.

5. Give the profile a recognizable name, then click Apply & Close.

6. On the Profiles tab, select the new profile, then click Reset.
   A message warns that this will reset the selected profile to system defaults.

7. To continue, click Yes.

8. To apply the new profile, in the Profiles window, select the new profile and click Set Current.

If the times improve with the new profile, this suggests an issue with customer customizations and further investigation of those customizations for any delays.

The following suggestions refer to the creation of MMS files:

• An MMS file is automatically created if the surface contained in a drawing contains more than one million points. Disable this automatic file creation in the Options menu.

• The MMS file is only created if the surface is contained in the drawing file. The user can check how many points there are in the surface: Surface Properties  Statistics  General  Number of Points.

• Since the MMS file is only created if the surface is contained in the drawing file, you can prevent the MMS file from being created by changing the “Data Reference Status” of the drawing file from “Geometry Stored in Drawing” to “Reference Only”, and then saving the drawing file.

• Orphaned MMS files, which don’t correspond to any drawing file, must be deleted manually.

Save operations fail due to DREF issue

See KB article 11225.

Bentley MicroStation GeoPak

Global File Lock is not supported when using Bentley MicroStation GeoPak.

GeoPak is part of an integrated civil design and engineering software package developed by Bentley Systems. GeoPak is a comprehensive software package that covers every project phase from construction to final quantities and construction stake-out. The software works with the MicroStation graphic environment, providing a true interactive design.

Esri ArcGIS ArcMap Geodatabase

Esri ArcGIS File Geodatabases

File geodatabases are utilized by multiple generations and classes of Esri applications. While ArcGIS Pro is the primary application, and is not scheduled to be retired, the experience of Nasuni Global Locking with ArcGIS Desktop, ArcMap, and ArcCatalog is expected to be the same.

ArcGIS projects using geodatabases can open many files at once to create a drawing or to access drawings and maps. Depending on your usage of ArcGIS within your Nasuni environment, these geodatabases could either reside on and be accessed from a single Nasuni Edge Appliance, or they could reside on a shared volume and be accessed remotely from multiple Nasuni Edge Appliances.

When the geodatabases are located on a shared volume and under Advanced GFL, the transactions to open tens, or sometimes thousands, of connections at once can overwhelm the locking system and slow down the file opening and editing process extensively.

Guidelines for using Esri ArcGIS applications with Nasuni include the following:

• There are two suggested options for storing ArcGIS data on Nasuni with a multi-site collaborative use case.

• Option 1 - Place all ArcGIS files under Advanced GFL.
  This includes the project files, reference files, personal geodatabase files, and external geodatabase files.
  As mentioned above, there can be overhead with Advanced GFL when used with the geodatabases. If this overhead is too much, consider Option 2.  

• Option 2 - Relocate only the external geodatabases to a single central Nasuni Edge Appliance and folder structure that is not enabled for either mode of GFL. Then require all GIS requests to these external geodatabases to be associated with this central Nasuni Edge Appliance.
  This option removes Advanced-GFL entirely and allows the local SMB locking to provide appropriate access to the geodatabases.

• Optimized-GFL is not supported or recommended with ArcGIS files, due to potential data loss.

• There is no need to relocate all Esri project files (.aprx). Except for geodatabases and certain reference files, Esri projects can function under Nasuni’s Global File Lock Advanced mode.

• In ArcGIS Pro, a project’s default “personal” file geodatabase can be located in a directory that DOES NOT have Global File Lock (GFL) enabled.

• The ArcGIS programs have their own locking capabilities that prevent Esri geodatabases from being modified by two different users at the same time. Moving the geodatabase file to a shared volume with GFL can impact the application’s own ability to protect itself. Though rare, if two users do edit the same GIS file simultaneously between snapshots, while attached to separate caching servers, the system creates a second file with a label for identification. The conflict can then be reconciled manually by the Esri User. This situation is a rare occurrence.

• Create a similar folder structure within the share called:
  Drive Letter:\*SITENAME*\GIS\ArcMap_GeoDB_Projects\Project Name-Number\

• Clear out the "Local Caches" folder periodically on each user's local machine. The goal is to keep the cache under 250 MB for optimal performance. The local caches folder can be cleared by going to "C:\Users\’Username’\AppData\Local\Esri\Local Caches" and deleting the contents of the folder.
  This is especially necessary if working on Aerials, because ArcGIS scans every file in the Local Caches directory before committing a change.

• Keep the number of Folder Connections in ArcGIS to a minimum. For example, if you are working a project in \\data\projects\Boston, make sure that ArcGIS is connected to that same path, not to \\data\projects or to \\data\projects\Chicago, because ArcGIS scans all the files in those directories as well, even if they are not in use.

• Keep the number of add-ins, add-ons, and toolbars in ArcGIS to a minimum in order to work on the project. If a project does not require a certain add-on, disable it until it is necessary.

• Use the following checklist to ensure that the configuration is correct:

• Computers should be running Windows 10 or later, not Windows 7.

• DFS Review: verify that each office is connecting to its local Nasuni Edge Appliance.

• ArcGIS should be running the ARC GIS version 10.7 or later.

• In a single appliance setting (not a shared volume), it is preferred to place geodatabases in a non-Global File Lock location.

• Copy all non-Global File Lock geodatabase folders into the local cache.

General suggestions for optimizing Nasuni with CAD software

While the performance of Nasuni’s global file system with CAD software depends on many factors, Nasuni recommends the following general settings and procedures to enhance performance:

• Firewall settings:

  • Ensure that port 443 is open outbound to the FQDNs in the Firewall Best Practices document.

  • Set the firewall policy to NOT scan, process, or log port 443 traffic from the Nasuni Edge Appliance.

• Nasuni Edge Appliance settings:

  • Set the volume sync schedule to 5 minutes (on Volume Properties page).

  • Set the volume snapshot schedule to 10 minutes (on Volume Properties page).

  • Disable the Antivirus Service (on Volume Properties page).

  • Set the CIFS (SMB) protocol level to CIFS & SMB3 (Configuration —> General CIFS Settings).

    Note: If using ArcGIS, set the CIFS (SMB) protocol to CIFS & SMB2.

  • Quality of Service (Configuration —> Quality of Service): Set QoS to ensure that the minimum bandwidth is above the values recommended above (such as 50-100 Mbps). Note that large CAD files might require more bandwidth.

• CAD software:

  • Ensure all users are on the same update or service pack for that CAD software release.

• User computer settings and procedures:

  • Suggested configuration: 16 GB of RAM, Solid State Drives (SSDs).

  • Suggest using Windows 7 64-bit or Windows 10 64-bit.

  • Cloud technologies rely heavily on DNS. Microsoft’s best practice is to have a name server at each location.

  • Windows 8 operating system and previous versions of Windows, along with many applications, have a 256-character limitation in the file structure. Move files up in the directory path to avoid reaching this limit, or shorten file path names.

  • Ensure that workspace environment variables use new share names and paths.

  • Ensure that antivirus software is not scanning mapped drives.

  • Use an exclusion list with antivirus software, so that it does not scan CAD software files. Typical file extensions are listed above.

• User settings and procedures:

  • Empty the user’s profile %temp% folder at least once a month.

  • The number of add-ins/addons that are in your toolbar can severely affect performance.

  • For Windows photo browsing, move photos to a non-collaborative directory. Use Windows 10.

  • Turn off Windows preview pane. The preview pane in Windows 7 can cause latency when traversing the network.

Appendix: Recommended modes of GFL

Tip: When using Advanced mode, oplocks are enabled by default.