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- Jul 26, 2012
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- Your Mac's Specs
- MBA i7, 8GB RAM, 512 GB SSD, High Sierra; iPad 3rd Gen, 32 GB, iOS 9; iPhone 5E, 64 GB, iOS 11
Many thanks, ManoaHi
I'm still looking for the most appropriate external disk to buy. If you think my iMac HD is nearing the end of its life, is there any merit in having a bootable Ext HD? If so, how do I do this?
When you say clone my internal disk, do you mean make a TM backup of it?
John
I don't want to recommend any disk. I have had nothing but trouble with Seagate, with WD giving me nothing to worry about with them, yet many others have had the exact opposite situation. A bootable clone is useful in that you can use this as your primary disk, until you have time to take your iMac in for a disk replacement and then you can clone it back. The only thing to remember is to get a disk with a higher capacity than your current 1TB. You'll need to buy cloning software. This form tends to prefer Carbon Copy Cloner (CCC), but that is $40, but for $10 less, you could get SuperDuper (SD). You should also get a 8+GB flash drive and install macOS on it with the cloning software. You then can boot from that flash drive which will make the cloning faster, but a thumb drive is killer slow but I believe you should always have an alternative booting method. I have several Macs and I always clone the disk before I upgrade the major upgrades (like Yosemite to Sierra) and just let TM do the rest. TM is not a clone and generally won't be bootable and it can't take any open files nor any of the system files. I've made all my Macs Solid State Disks (SSD) and clone and replace was "normal", because I needed the speed boost without outright replacement of the entire Mac, I even do the max memory upgrade. This also had the alternative that I could test the drive before swapping them.
Even if you aren't going to replace the disk yourself, I would still recommend a d USB 3 External Enclosure for SATA drives because bare SATA drives tend to be cheaper than new USB external drives and offer some flexibility. Buy CCC or SD and it will take you through creating a clone. There are several options to set, bootable being one of the settings. If you want to see how to replace an internal HDD, check YouTube there are loads of videos on how to do that. It might be worthwhile if you cannot afford long down times. If you are near an Apple store, if you make clear in your Concierge reservation that you want to wait until they have the disk in stock, because due to the age of your iMac, they might not stock them. (not that your Mac is too old, it isn't too old by a long shot it's just that beyond Apple Care or Apple Care +, they don't keep the stock of the parts, they'd have to order the parts. Also, in the Apple store they have other diagnostic software, because if is the disk subsystem, your main logic board may have to be replaced and a new disk won't be any better that it is now. Generally HDDs are suspected first and they are the cause in the vast majority of cases, and more likely for you that it's the disk for you since other than TM, the Mac works for you. For now, get a new disk, even a stand alone and copy your works onto it, every now and then just keep them updated. That way, even if you have to replace your Mac, you wouldn't be dead in the water.
I'm glad that you at least tried to do a backup. I would recommend that you don't use the Admin login for your general work. Create a regular user login and if you're willing to go through it, child protection which can help keep odd things out. On all my machines, regardless of OS, I only use regular user accounts and login as admin when only absolutely necessary.