to partition the main disk with OS or not ?

I'm not entirely clear what you are trying to achieve with the old internal Hard Drive.

First I want to clarify that you only had macOS 10.13 High Sierra installed on the internal Hard Drive....is this correct?

Second, you want to add a small partition to the internal Hard Drive?

If so, then my question is why do you need another partition, especially such a small one? I usually never recommend partitioning any drive because people almost always realize later on that one or more of the partitions is too small. However, since you have a second boot drive you want to use, it is a bit less of an issue.

What file system is being used on the Hard Drive? If it is using the APFS file system, then you can instead just create a new APFS volume. A new APFS volume which resides within the same Container acts a lot like a partition, but doesn't require changing any actual partitions or specifying any sizes since all APFS volumes within a single Container share the same storage pool. Each APFS volume is separate from the others and each can be individually mounted & unmounted or even encrypted.

Third, Is your goal to still have the original macOS bootable on the internal Hard Drive as well as have the bootable external SSD clone?

My concern for a computer that is 14 years old is that the internal Hard Drive is likely worn out or failing. Even if the Hard Drive has no bad sectors, it could still have a high Load Cycle Count due to macOS being very aggressive with the sleeping & waking of Hard Drives. When the Load Cycle Count of a Hard Drive exceeds the manufacturer's expectations, then in my own personal experience the Hard Drive begins to have performance issues and even some odd behaviors.

You can check the health of the Hard Drive by using the third party app DriveDx (free trial period). For a Hard Drive usually any "Warning" or "Failing" items indicates a worn out or failing Hard Drive respectively....both mean the Hard Drive has issues and should no longer be used. Unfortunately checking the health of an SSD is not quite as easy or clear cut. Feel free to post the complete DriveDx text report here using the "Additional Text" icon which looks like a piece of paper on the forum editing toolbar.

When using a third party SSD, it is usually recommended to enable TRIM on the SSD. Usually to enable to TRIM on a third party internal SSD you would use the following Terminal command:

sudo  trimforce  enable

However, I don't think that works for USB SSDs, but I don't know if it makes a difference because you are booting from that external SSD. It doesn't hurt to try that command while booted to the external SSD.

Continued....

funds being limited , read I'm skint , I cannot afford another 1T SSD

so in a nutshell , if possible , partition the spinner or indeed the SSD to 256 GB clone it and keeping all my software would be ideal

if possible

If your external 1TB SSD is using the APFS file system, then you can create a new APFS volume on it to achieve the same goal as partitioning a drive would give you. A new APFS volume created within the same hidden APFS Container will share the storage pool with all of the other APFS volumes within that Container without requiring any dangerous size limitations. Each APFS volume can be individually mounted & unmounted just like a partition. The data on each APFS volume is separate from the data on the other APFS volumes.

Add, delete, or erase APFS volumes in Disk Utility on Mac - Apple Support

I am a very old painter , Art historian and yacht designer , and I mean very old , therefore age added to lack of knowledge in all things Mac leads to stupid questions

They are not stupid questions. Asking questions is always a good thing. It is one of the ways we learn. Experimentation is another.

I cannot emphasize enough the importance of keeping LRC and PS

I understand. That is not an easy task since it depends on you keeping good copies of the cloned drive/image file. That is hard to do when money is tight.

It is a shame that many developers don't provide easy access to reinstall older outdated copies of their software. I tend to vote with my wallet and try to only purchase software from developers that treat their users & customers with respect by making it easy to reinstall their apps....and providing access to the older outdated versions for operating systems that are no longer supported.

please forgive me for being so forward

I've got a (new for me ) iPhone 12 , runs iOS 18 , and suddenly does not prompt for PIN

it happened from one day to tomorrow , literally

any idea , please ?

Start a new thread in the iPhone forums to get assistance for iPhone & iOS issues.

iPhone - Apple Community

viorel275 wrote:

as with an external via Thunderbolt works ok , is there any possibility to disable the spinner inside the Mac?

Sort of.....you can prevent a drive from automatically mounting when macOS boots by using the instructions in the following article:

Prevent a volume from mounting at startup - Apple Community

The volumes & drive will still be visible within Disk Utility which means if you want you can still manually mount the volumes by using Disk Utility.

Edit: Here are a few Apple articles for relocating the iPhoto/Photos, iTunes/Music, and Movie Libraries:

Move your Photos library to save space on your Mac - Apple Support

Change where your music files are stored on Mac - Apple Support

Move your iMovie for Mac library - Apple Support

viorel275 wrote:

is this update necessary ?

Download macOS High Sierra 10.13.2 - Apple Support (IL)

all I'm doing on Mac is edit photos and design boats

is there any possibility to kill off my PS and LRC versions ?

Doubtful for a minor OS update patch, but it is always a possibility especially depending on whether those apps (PS & LRC) are already fully patched for their major version. If those apps are not fully patched, then an OS update may require those apps to have an update patch installed. Would those patches still be available today? I have no idea. Companies like Adobe don't really care about anything other than their most current product which is now a subscription model.

If you had a spare drive with a complete clone, you could always test out the macOS update patch to see what happens. FYI, the macOS High Sierra update patches go up to 10.13.6 so 10.13.2 is even out of date for High Sierra.

Otherwise, I would say if it isn't broken, don't mess with it since High Sierra is way out of date anyway.

cleanmymac app is not accepted by about 50% of Mac users

any app that does the same please ?

There is no need for those types of apps. They usually cause more problems than they solve because they interfere with the normal operation of macOS at a very low level. Plus, macOS High Sierra is so old, I doubt you will be installing any more apps on it than what you already have since it is unlikely any apps in the Apple App Store are even compatible with High Sierra these days.

Besides, installing more apps increases the likelihood of causing problems to your delicate High Sierra installation where you want to keep alive your vintage Adobe apps (PS & LRC), especially since Adobe no longer allows reactivation of that older software (or so I heard the other day in another thread).

I think everyone should read the following article as it contains great advice on how to keep your system running smoothly and how to protect the system & yourself:

Effective defenses against malware and other threats - Apple Community

do you know a light firewall to block in and out connections ?

( compatible with Sierra , I mean )

You should have no need to run any firewall on macOS. Most home networks are already protected from direct incoming access from the Internet by your network router. Routers usually have their own firewalls, plus most home networks are on a NATted network with an IP address that is only available to others on your home network.

The only people who need to use a firewall with their OS are those whose computer is directly connected & exposed to the public Internet or are on a network with others who are dangerous & cannot be trusted. Most average users are not in those situations.

The Good Samaritan became almost extinct

when I look at all your efforts to help ( me in this particular instance ) I see , with great joy , that The Good Samaritan still exist

all your time spent to enlighten me was taxing on you one way or another

and the care you showed gives me renewed hope that not all is lost in this crazy world we live in

You are most welcome and thank you for the kind words. It has been a pleasure assisting you and sharing my knowledge & experience with you and others here.

viorel275 wrote:

the Mac was bought refurbished by allegedly them

Not sure what refurbished means since people throw that term around a lot when referencing used devices. Unless it came from Apple's refurbishment website, or some other respected vendor who actually does refurbish .....aka repair & update the device, I would say it is just a used device with an unknown history which could be hiding problems.

I got drawn into windoze system a long time ago

through bitter experience I've learned the good practice of having the OS on a separate HDD , or indeed partition and an image somewhere else

if this way applies to Mac I have no idea

I'm not sure exactly what you mean here. If you mean put the OS on one small partition and your data on a larger partition on the same drive, then don't do it. I don't recommend partitioning any drive beyond what the OS installer uses as a default. People usually realize much later that one or more partitions are too small.

I understand the reasoning here that you can keep your data on the partition & just reinstall the OS on the other partition, but you are just asking for trouble in more ways than one. macOS doesn't do well by relocating the home user folder. Just make sure you have a good backup. If for some reason you need to perform a clean install, then you should be able to restore from your backup.

I've decided to bite the bullet and replace the spinner with an SSD from OWC - inside the machine i.s. ;

I do have a SSD @ 256 from OWC as well

Be careful if you open up the iMac. It is not easy to work on. There are several very fragile cables & connectors which are hard to see and hard to connect/disconnect since there is very little room to work when trying to disconnect/reconnect since you will be holding the large heavy display while trying to work with those cables. And I've seen the LCD Panel crack under its own weight if not handled properly (must always be vertical).

Some of those iMacs require a temperature sensor cable from OWC (I don't know if the 2011 is one of those models since I recall seeing a note from OWC that some models may have received a firmware update so the temp sensor was no longer required, but I'm not certain which models or if I'm recalling it correctly).

my paranoia , and it is the right word , is that I have old versions of Lightroom Classic , Photoshop , and three perfectly good programs for boat design

LRC and PS are absolutely unobtainable today ,

You definitely want to keep a cloned image in order to restore the system in the event of a drive failure or needing to wipe the system to fix a problem by restoring to a known good clone. However, keeping a clone or a clone image file is not without risk either since a drive may go bad just sitting. FYI, an SSD can lose its data if the SSD is stored unpowered for a year or so (I've seen some reports that some SSDs can lose their data in as little as six months if left unpowered).

for High Sierra , i

in my presumed ignorance of all things Mac I thought that the OS on an internal SSD is the right way and the 1T external for storage

the spinner and the 1T external are journaled

It is fine to have macOS on one drive and store your large data files on another physical drive as long as the other drive is just a pure data drive. Apple has instructions for placing some app Libraries which may contain large amounts of data onto another drive....Libraries such as iTunes/Music, iPhoto/Photos, Video. You can also store your regular files on another physical drive.

For a Hard Drive, you definitely want to stick with the MacOS Extended (Journaled) file system (aka HFS+) since the APFS file system makes a hard drive work harder and causes the Hard Drive to wear, plus APFS on a Hard Drive will impact the Hard Drive's performance as well.