What is NVFS?

NVFS (non-volatile file system) is a way of describing the memory on a palmOne device. Before NVFS, the data in your handheld was stored in "volatile" memory that required a constant stream of low power to maintain the data. If your handheld battery became completely drained, you would lose your data until you performed a HotSync operation to restore it from your PC.

By contrast, some of our devices (starting with Treo 650 and Tungsten T5) use "non-volatile" memory, meaning that it doesn need power in order to store data. You can detach your battery or let it run down completely, and your data will remain in the device.

This article talks about non-volatile memory on the Treo 650 smartphone specifically¹. Be sure to pay particular attention to the information about how much data you can transfer.

Advantages of non-volatile memory

We think you'll like NVFS because it offers two great benefits:

1. Now you can swap out your battery — your data will still be there: With non-volatile memory, you can remove or swap your battery as you like; your handheld doesn't need power to keep your data safe. This lets you use a secondary battery for extended trips away from your charging station. Just open the back of your smartphone, pop out the drained battery, and insert the secondary battery (without having to worry about losing your data in the process).

    

2. You can be more casual about charging: Don't always have time to charge your battery? Now your smartphone won't lose data because you forgot to charge the battery or because you ran low on power and have not been performing HotSync operations as regularly as you should. Breezily, place your handheld in a drawer and head for the beach in Jamaica (assuming you like to travel without any of your connectivity devices) knowing that you can return in a month or two without risk of your data being erased due to a low battery.

Note: Even though non-volatile memory keeps your data without battery power, we still encourage you to keep copies of your data by performing frequent HotSync operations, or using a an expansion card backup application. It is always possible to erase a local file in error, and you will want a recent backup from which to restore.

What else is new: non-volatile data structure

This new data structure has two main implications:

1. Data takes up more space: With NVFS, applications and data files may occupy a larger amount of memory on Treo 650 than they would on a handheld that uses volatile memory. With the Palm Operating System (Palm OS), each file contains internal records. The internal record size for files on NVFS is always exactly 512 bytes; records over 512 bytes are spanned across multiple records of 512 bytes. By contrast, with volatile memory, the record size can vary.

    

   • Real world implications: Your applications and data will have a larger footprint in the non-volatile memory space of your Treo 650 than on previous devices that use volatile memory. The growth depends upon the size and number of records inside an application or data file. The new size of your applications and data may not be any larger than on previous devices, or, more likely, they may require as much as one-third more space on your Treo 650. For example, a typical address book will take about 800KB more space on a Treo 650 than on previous devices. More about that later.

     If you have a Palm OS device with 16MB or more of volatile memory, and this space is filled to capacity, you may have to make some choices about which applications to move to your Treo 650, and which to place on expansion cards⁴.

    

2. A few applications won't like the NVFS: This is a rare case. Your Treo 650 includes 10MB of RAM in addition to its non-volatile memory. A small number of third-party Palm OS applications may use a very large data file, more than 10MB, containing many records. Such an application may need to access all the records at once (for example, when sorting all records); this can cause problems under NVFS.

    

   • Real world implications: If you perform a function in one of these applications that requires more than 10MB of RAM, you will see a "Memory full" error on your Treo 650. We are working closely with third-party developers to help them rewrite their applications to work with NVFS. If the "Memory full" error appears when you're using an application, visit the third-party developer's website to see if an updated version of the software is available.

Upgrading to a Treo 650 from other Palm OS devices

Most people will have no problems upgrading to a Treo 650 using the standard Palm Desktop installer included on the Treo 650 CD. The information below is useful if you choose to do this manually, or if your Treo 650 becomes too full when upgrading from a previous device with volatile memory.

What device are you upgrading from?

Depending on your previous device, you may or may not experience difficulties storing all your data on your new Treo 650.

The Treo 650 contains 23MB non-volatile memory (22MB on the multi-lingual version). However, the installer on the Treo 650 CD pre-loads an additional 2MB of applications onto your smartphone when you perform your first HotSync operation — this is the Documents To Go viewer provided with your device.

A quick guideline for determining whether your Treo 650 will become too full is how much memory your previous handheld contained².

Exactly how much can I transfer to my new Treo 650?

In order to ensure a smooth upgrade, you may need to move some of your third-party applications to an expansion card⁴. Of the 22MB-23MB memory on your Treo 650, 2MB is taken by the Documents To Go viewer, leaving 20-21MB for your previous device's data. But remember, those applications and data files may occupy more space on Treo 650's non-volatile memory than they did on your previous device.

As a general rule, add about 33 percent to the existing occupied memory on your previous device. This allows for the larger data files of your Treo 650's NVFS, including PIM application data (your Contacts, Calendar, Tasks and Memo items) that will occupy a larger space, as well as third-party applications that will probably not grow as much. Because the exact amount of data expansion depends on the number of records and how full they are, this is only a rough estimate; your experience will differ.

Will you wind up with less than 2MB of free space? After you calculate how much of your Treo 650's memory will be used by your applications and data (including 2MB for the Documents To Go viewer), you may find that you will have less than 2MB of free space. If this is the case, we recommend that you move some applications to an expansion card⁴ before migrating your data to a Treo 650.

What happens if my Treo 650 runs out of memory when I'm upgrading?

When you use the Treo 650 CD to upgrade to your new smartphone, you'll perform your first HotSync operation with the Treo 650. If there isn't enough memory on your Treo 650 to accommodate your data, you'll see an error in the HotSync Log that says "Handheld full. The data storage of the handheld is full."

This error occurs because the HotSync process does things in this order during an upgrade (technically, a recovery HotSync process):

How do I free up memory on my Treo 650?

Usually, you can move large applications to an expansion card; you can also shrink or delete unnecessary files. For more information and tips on clearing memory, see Knowledge Library article 26571.

Storing applications and data on expansion cards instead of internal memory

How much larger does Personal Information Manager (PIM) data get with NVFS?

PIM data is your most important data — your Contacts, Calendar, Tasks and Memos. Whether you synchronize with Palm Desktop, Microsoft Outlook, or another application, your PIM information is transferred to your smartphone during the HotSync process.

As you recall, with the non-volatile system on your Treo 650, applications and data files generally occupy more memory than they did on your previous handheld. This is definitely true of PIM data. Every record in your PIM applications (that is, every individual in your Contacts, every Calendar appointment, every Task, every Memo) will always occupy exactly 512 bytes. With previous devices that used volatile memory, the record size could vary, depending on how much information you had in a record.

For example, on your previous device with volatile memory, you might have had one Contact that had only a First Name, Last Name and email address, and another Contact that had all the fields filled with information (Company, Work phone, Address, etc.). With the previous volatile system, the first Contact would have taken a smaller amount of memory than the second, fuller contact. With the new NVFS on Treo 650, however, both Contacts take up the same space, no matter how much information they contain: exactly 512 bytes.

In the table below, we estimated an average file size for your PIM applications, and show how these data files will expand under the NVFS of Treo 650.

Note: This is an estimate of an average user's number and size of records. Your device will differ from this approximation, but you can see how the data files expand under the Treo 650's NVFS.

Expanded PIM features in Treo 650: Also adding to the data file size is the fact that the Treo 650 offers expanded PIM features that store more data than previous Treo smartphones. Curious about these new features? We detail them in these Knowledge Library articles: Contacts • Calendar • Tasks • Memos.

Will my third-party applications expand as much as my PIM data does?

Probably not.

You'll remember that we said to add about 33 percent to the existing space taken by applications and data files on your previous handheld, to accommodate the larger files on your Treo 650. As the table above shows, your PIM data will probably expand by a lot more than 33 percent.

Each third-party application is structured differently internally, and some applications may be unaffected. The expansion is dependent upon the number of resource records inside the file and the record size of each. Many applications have associated data files that may become larger under Treo 650's NVFS. Third-party developers will quickly move to optimize their applications to make better use of NVFS. If you're concerned about a third-party data file expanding dramatically on your Treo 650, contact the third-party developer to see if a new version of the application is available for Treo 650 users.

Footnotes