Catalogs Using LRc / Photoshop on BOTH a MAC and Windows

[rebop]

Lightroom Version Number

13.5

Operating System

1. Windows 10
2. macOS 15 Sequoia

Using LRc / Photoshop on BOTH a MAC and Windows

Not at the same moment, of course And this is a non-rush question. Trying to be prepared.

As some my have read, I am considering a MAC for the first time in MANY years. Just started to think about where things go and how I would use catalog, etc.

The executables are easy. Here is what I have now in Windows. Where would these go in the MAC so that all things match?:

Lightroom Catalog: C:\Users\bob\Pictures\Lightroom\Bob's Lightroom Classic
Watermarks, end caps, etc: C:\Users\bob\Pictures\Lightroom\Lightroom Stuff
Caches and preferences: C:\Users\bob\AppData\Local\Adobe
Presets and TONS of custom stuff: C:\Users\bob\AppData\Roaming\Adobe\Lightroom

For example:

I have a ton of custom stuff there.
And I think NIK collection is in there as well. I wonder where for Lightroom? Will look. Its older paid for before FREE NIK. May not have a MAC installer.

AHHHH, NIK Stuff:

C:\Users\bob\AppData\Local\Google

And then, where do I put the catalog? Or do I keep two copies and sync them before each computer use?

All Images will be on my NAS.

Photoshop easier, I think.

C:\Users\bob\AppData\Roaming\Adobe\Adobe Photoshop 2024
C:\Program Files\Adobe\Adobe Photoshop 2024\Plug-ins

I **think** that is all I customized in PS but must be preferences as well.

What do you think? If I were just transferring, would be easier. But at least for a time want to be able to use my images on either computer.

 

[Rob_Cullen]

I will start by saying that using the same Lightroom-Classic catalog on two computers is problematic.
Victoria has written a full article on this topic-
https://www.lightroomqueen.com/how-to-lightroom-catalog-multiple-computers/#selfcont

For a reference to File locations see-
https://www.lightroomqueen.com/lightroom-classic-file-locations/

 

[rebop]

I'll look at both links, thanks. But, need to say that for maybe 10 years I synced my catalog from Desktop to Laptop using M'soft synctoy with no issues. As a matter of fact, my image library was so small then I synced that as well. Nowadays needs to be on my NAS.

 

[rebop]

Helpful article on file locations. Particulalrly pointing out preferences are not cross platform!

 

[rebop]

And good info on Catalogs as well. Thanks for the pointers.

I think maybe catalog on the NAS would work along side my image libraries. Except if i take the laptop out for a very rare tethered shooting. But then I could have a separate catalog for that and import the images into the default catalog on the NAS when back. That should work. And, the NAS backs up to an external for images and LR stuff 3 times a week, so not only catalog backups daily, but a separate drive with a copy. Feeling good about that solution.

 

[Rob_Cullen]

I think maybe catalog on the NAS would work

No, or maybe? The general consensus is- "Lightroom Classic catalog files cannot be on NAS storage."
See the forum thread at-
https://community.adobe.com/t5/ligh...two-pcs-and-synology-nas/m-p/14135604#M337401

 

[rebop]

I'll go read. But the previous article suggested and extenal USB drive. So if that, why not the NAS????

 

[clee01l]

The biggest problem to overcome is have both Windows and MacOS recognise file on the same Catalog
The Catalog store the path to each image in two places. One is the 'absolutePath' and the other is the 'relativePath' fields. The 'relativePath' field is not resolvable if the images are on a different volume from the catalog in Windows OS. In Windows, the 'absolutePath' field contains a drive letter which MacOS or other Posix Compliant operating system can understand. IF the catalog and the images are on the same volume. Preferably with the image folders nested under the catalog folder, the 'relativePath' field is resolvable in both Windows OS and Mac OS. If the Presets are stored with the catalog then they are interchangable, All other preferences and settings need to be replicated on either computer.

If this is done then the catalog and images are easily used by LrC on either machine.

 

[rebop]

This is making absolutely no sense to me. I could see not being able to have multiple users. Makes perfect sense. But just opening the catalog from the NAS should be NO different than an external USB drive. And the articles do not explain that difference to me. There is no SQL on the USB as well. What is different????

 

[rebop]

The biggest problem to overcome is have both Windows and MacOS recognise file on the same Catalog
The Catalog store the path to each image in two places. One is the 'absolutePath' and the other is the 'relativePath' fields. The 'relativePath' field is not resolvable if the images are on a different volume from the catalog in Windows OS. In Windows, the 'absolutePath' field contains a drive letter which MacOS or other Posix Compliant operating system can understand. IF the catalog and the images are on the same volume. Preferably with the image folders nested under the catalog folder, the 'relativePath' field is resolvable in both Windows OS and Mac OS. If the Presets are stored with the catalog then they are interchangable, All other preferences and settings need to be replicated on either computer.

If this is done then the catalog and images are easily used by LrC on either machine.

So, right this very moment, Cletus, I have my catalog on C:\ and my images on my NAS, F:\. There is no issue at all. Works a little slow opening the image file first time, but then as if it were all on C:\. Why would having the catalog on the NAS be any different than C:\ or a D:\USB stick??

 

[clee01l]

So, right this very moment, Cletus, I have my catalog on C:\ and my images on my NAS, F:\. There is no issue at all. Works a little slow opening the image file first time, but then as if it were all on C:\. Why would having the catalog on the NAS be any different than C:\ or a D:\USB stick??

On a Mac you have no C:\ drive. Where are you going to put the Catalog so that both Windows LrC and Mac LrC can access it? You can not put it on a NAS, the Database manager won't let you open a Catalog on the NAS. drive. This is a constraint of a single user database system.

 

[rebop]

On a Mac you have no C:\ drive. Where are you going to put the Catalog so that both Windows LrC and Mac LrC can access it? You can not put it on a NAS, the Database manager won't let you open a Catalog on the NAS. drive. This is a constraint of a single user database system.

Whatever the equivalent of C: is. My drive. My spinning disc. Whatever Apple calls it

And no one can tell me why the catalog can work off an External USB drive and not the NAS. Makes no sense to me and there has been no clear explanation I can find. Database management is done on the computer. It should just be a file like any other.

 

[clee01l]

And no one can tell me why the catalog can work off an External USB drive and not the NAS. Makes no sense to me and there has been no clear explanation I can find. Database management is done on the computer. It should just be a file like any other.

The Primary Volume on a Mac is Named MacIntosh HD. It is the root of the file system and is shown as the first "/" or root directory in the file path. All other volumes are mounted in the /vol folder. If you have ever used a UNIX operating system you will understand this

The explanation for single user databases is that there is no user access control management that permits multiple users to open the same database. On a NAS, there is nothing to prevent a second user opening the data base file and writing to it while the first user has the database open to write. This would destroy the integrity of the database. The SQLite database engine in LrC acknowledges that and if the database is on a network volume won't permit any one to access the database file. To use a networked data base there needs to be a user manager on the server that can log individual users (clients) and grant them exclusive access to certain records. SQLite is not like Oracle or SQLServer which run on a Server (NAS)

 

[Gnits]

Here is the advice from Official Adobe Documentation.

I read an explanation a long time ago…. I do not trust my memory to recall exactly… but reading data from a disk is read by sector or block, while data from a network drive is delivered in packets, delivered thru various tcp/ip protocols, which have built in error correction, packet resend features. The database drivers are comfortable with direct read from disk, but not able to manage negotiation thru network protocols.

A lot may depend on how a network catalog is used. If used to simply copy a backup copy of a catalog to another Mac or Windows device then it should work. If interacting from a network device then that opens various risks.

In the early days of Lr…. I assumed (incorrectly) that a pro version would be released which would work comfortably with pro level database systems. Such systems might be attractive for businesses with internal tech support to manage the admin required for such systems. I have given up any thoughts of such developments.

 

[rebop]

The Primary Volume on a Mac is Named MacIntosh HD. It is the root of the file system and is shown as the first "/" or root directory in the file path. All other volumes are mounted in the /vol folder. If you have ever used a UNIX operating system you will understand this

The explanation for single user databases is that there is no user access control management that permits multiple users to open the same database. On a NAS, there is nothing to prevent a second user opening the data base file and writing to it while the first user has the database open to write. This would destroy the integrity of the database. The SQLite database engine in LrC acknowledges that and if the database is on a network volume won't permit any one to access the database file. To use a networked data base there needs to be a user manager on the server that can log individual users (clients) and grant them exclusive access to certain records. SQLite is not like Oracle or SQLServer which run on a Server (NAS)

I have no need for multiple users to access the database. None. Will never happen. If I did, I could understand. But to me, I see no difference between that and an external USB file as a single user.

Of course, a USB stick will be my second choice.If I put the catalog on any internal drive, I will sync it before any use between two computers. But putting it on the NAS is set it and forget it.

So even rthought I have said no desire for multiple users several times, we keep coming back to that as the reason why it will not work.

Lets go read the next explanation

 

[rebop]

Here is the advice from Official Adobe Documentation.

View attachment 24431

I read an explanation a long time ago…. I do not trust my memory to recall exactly… but reading data from a disk is read by sector or block, while data from a network drive is delivered in packets, delivered thru various tcp/ip protocols, which have built in error correction, packet resend features. The database drivers are comfortable with direct read from disk, but not able to manage negotiation thru network protocols.

A lot may depend on how a network catalog is used. If used to simply copy a backup copy of a catalog to another Mac or Windows device then it should work. If interacting from a network device then that opens various risks.

In the early days of Lr…. I assumed (incorrectly) that a pro version would be released which would work comfortably with pro level database systems. Such systems might be attractive for businesses with internal tech support to manage the admin required for such systems. I have given up any thoughts of such developments.

Now that is more interesting if accurate. I want to say the files are reds through SMB, but honestly would have to look.And as a mapped netwrok drive, TCP/IP is definitely involved.

I would not be copying this anywhere Gnits. That is the reason for putting it on the NAS ANd I had seen this from Adobe. Problem is, there is no explanation why not in the Adobe FAQ's. And I am a need to know person.

Just looked and it is SMB installed on my NAS.
https://www.techtarget.com/searchnetworking/definition/Server-Message-Block-Protocol

 

[rebop]

OK, so , of course, the catalog is not just a "read only" file, but info writes to it as well. That is where the issues seem to be and is making a bit more sense to me. Microsoft has a good bit of info on this:

https://learn.microsoft.com/en-us/t...ile-operations/support-network-database-files

Excerpt:
"...Microsoft does not support SQL Server networked database files on NAS or networked storage servers that do not meet these write-through and write-order requirements.

Because of the risks of network errors compromising database integrity, together with possible performance implications that may result from the use of network file shares to store databases, Microsoft recommends that you store database files either on local disk subsystems or on Storage Area Networks (SANs).

A network attached storage (NAS) system is a file-based storage system that clients attach to through the network redirector by using a network protocol (such as TCP/IP). By default, if access to a disk resource requires that a share be mapped, or if the disk resource appears as a remote server through a UNC path (for example, \Servername\Sharename) on the network, the disk storage system is not supported as a location for SQL Server databases..."

So, flash drive likely best choice. So few options for something small and USB C for flash drives now-a-days. In my Let's Talk MAc topic talking about Thunderbolt docks. So I have two things to figure out today:

1. Can I switch computers to monitor, ethernet, peripherals between MAC and Windows computers by just moving the Thunderbolt cable?
2. If so, can I have the catalog on falsh attached to the dock and just grab it that way on either computer? One at a time, of course...

 

[clee01l]

I have no need for multiple users to access the database. None. Will never happen. If I did, I could understand. But to me, I see no difference between that and an external USB file as a single user.

The NAS is available for multiple users and the database file is thus available for any user with access to the NAS. Since there is no user control in SQLite, the developers are able to restrict the access only by not allowing any access if the Catalog is mounted on a network drive. This is the nature of SQlite. If it were not so, you could open the Catalog database file using Windows and make changes and While you have the file open to write with the Windows LrC, you could also open the same file using your MacOS and also make different changes, this would in effect corrupt the database. LrC has always used SQLite as the internal data base and there is no indication that Adobe would ever develop LrC as a multi user client/server app.

 

[rebop]

The NAS is available for multiple users and the database file is thus available for any user with access to the NAS. Since there is no user control in SQLite, the developers are able to restrict the access only by not allowing any access if the Catalog is mounted on a network drive. This is the nature of SQlite. If it were not so, you could open the Catalog database file using Windows and make changes and While you have the file open to write with the Windows LrC, you could also open the same file using your MacOS and also make different changes, this would in effect corrupt the database. LrC has always used SQLite as the internal data base and there is no indication that Adobe would ever develop LrC as a multi user client/server app.

Superfluous. I am the only user. Would have no need or desire for multiuser LRc and am not waiting with bated breath The real answer was Microsoft and the corruption that packet fragmentation can make to the catalog potentially.

 

[rebop]

Lightbulb!

Both have SD card slots. I assume they both format the same, yes? If so, perfect place for the catalog.

 

[clee01l]

Superfluous. I am the only user. Would have no need or desire for multiuser LRc and am not waiting with bated breath The real answer was Microsoft and the corruption that packet fragmentation can make to the catalog potentially.

Microsoft has nothing to do with it. SQL Server is a server side app that manages "industrial strength" client/server databases. It has nothing to do with SQLite Do not confuse SQLServer, Oracle or any other client/server data base with SQLite. An "industrial strength" client/server database has nothing in common with SQLite except that they structure the database file as tables and records and use a common Structure Query Language (SQL) to access data records in those tables.
That you are the only user has nothing to do with the multiple access ability of a Network computer. NAS are usually UNIX based. NAS is a network computer usually without a monitor and keyboard. And just as you can allow multiple users to log into your desktop computer (also a network computer in on the internet), multiple users can access the NAS. If more than one user is allowed to change a file at the same time, then one users changes are lost.

While you have no need or desire for multiusers to access your NAS, this is not how they are designed. They are desiged for multiple users. Please accept that as fact. It has nothing to do with LrC and everything to do with SQLite database integrity.

You probably have at least two users on your NAS, yours and the admin logins These may represent the same person but with different file permissions and access. My NAS has four users: the Admin (Me), My MacStudio TimeMachine client, my wife's MBP laptop for TimeMachine and me as an individual. You do not want any of these users to write to the same file at the same time.

 

[clee01l]

Lightbulb!

Both have SD card slots. I assume they both format the same, yes? If so, perfect place for the catalog.

SD Cards are usually formatted as FAT32 or exFAT, neither offer any User access security. This is why you can read and write in any computer or camera. Along with the Catalog file you need to store the Previews folder and the Presets folder (Lightroom Settings). So it is best to copy the contents of your Lightroom folder. You still need to resolve the path issue caused by Windows use of Drive letters in the 'absolutePath' of the catalog.

 

[rebop]

"You still need to resolve the path issue caused by Windows use of Drive letters in the 'absolutePath' of the catalog."

What would need to be resolved?

And they are FAT32. Would need to reformat to exFAT to use in both computers. Easy. And of course, the entire folder. As I mentioned, I synced two catalog "folders" for 10 years or so and familiar with what is needed there.

Starting to feel like a good solution. Once I understand what would need to be "resolved". Not concerned with security on the cards.

 

[clee01l]

What would need to be resolved?

The 'absolutePath' field must contain a drive letter when LrC in Windows opens the catalog file or the image will show up as missing in LrC.

MacOS when reading the same catalog file does not recognize drive letters, so any time you have a 'absolutePath' with Drive letters in the catalog, it also will show as missing. Every time you open the catalog on a different operating system you will be confronted with missing images and need to resolve this before going forward.

The only way I have found to make this problem go away is to use the 'relativePath' field in the catalog in such a way that the 'relativePath; is always defined and resolvable. This can only be done when the images are in subfolders of the same volume containing the catalog file. (i.e. relative to the path of the catalog file ) You have already indicated that you don't want to move your image off of the NAS.

 

[rebop]

Now that is an interesting new wrinkle.

So, since I do not have a MAC to play with yet, isn't it windows assigning a drive letter that is not affecting the folders and files? The SD changes drive letter depending on where it is plugged in. So where would MAC be seeing this drive letter than causes the issue? And once again, isn;t this identical to using an external USB for the catalogs for BOTH Win and MAC? I thought Victoria suggested that as a solution.

Unconfuse me, please.