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Help! Multiple Hard Drives with Identical UUIDs!

OK, i've been having a lot of problems lately with backup software (superduper! and time machine in particular), as well as itunes, where the apps seem to be confused about which external hard drive is which. this has had messy and in some cases disasterous results. after digging around a bit, i've discovered that an external hd (western digital 2t) connected directly to my mac, as well as three other hds (all western digital 2t drives) connected through a hub (anker usb 3.0 powered hub), have identical uuids.


anyone know why this happens? and what i can do to correct it?


thanks!

iMac / iBook / iPhone, Mac OS X (10.5.2)

Posted on Oct 8, 2013 1:38 AM

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Posted on Oct 8, 2013 3:40 AM

There was a long discussion about this in the private "Lounge" forum that unfortunately only level 6 & above users can see. (For level 6 & above users the topic is here.)


The gist of it is that quite a few WD Passport Studio 2 TB drives came from the factory preformatted for OS X with the same UUID. (A level 6 User confirmed that two he had been using regularly plus one fresh out of the box all had a UUID of 2CA31A4C-9B24-3F7D-A7A2-4B168E43FBBE. All were made in Thailand, but had different enough serial numbers to suggest they were made at different times.They were purchased from different sources.)


There was some speculation about how that happened, but clearly the error is Western Digital's, not something caused by OS X or users. You may want to contact WD customer support to see if they have any suggestions for how to fix this but the only thing I know of to correct it is to reformat the drives using Disk Utility, which will give each one a unique UUID.


This will erase the drives, so to save what is currently on them, I suggest that you connect them one at a time & clone their contents to another drive (obviously one with a different UUID!), reformat them, & then clone back their contents.

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Oct 8, 2013 3:40 AM in response to markmal

There was a long discussion about this in the private "Lounge" forum that unfortunately only level 6 & above users can see. (For level 6 & above users the topic is here.)


The gist of it is that quite a few WD Passport Studio 2 TB drives came from the factory preformatted for OS X with the same UUID. (A level 6 User confirmed that two he had been using regularly plus one fresh out of the box all had a UUID of 2CA31A4C-9B24-3F7D-A7A2-4B168E43FBBE. All were made in Thailand, but had different enough serial numbers to suggest they were made at different times.They were purchased from different sources.)


There was some speculation about how that happened, but clearly the error is Western Digital's, not something caused by OS X or users. You may want to contact WD customer support to see if they have any suggestions for how to fix this but the only thing I know of to correct it is to reformat the drives using Disk Utility, which will give each one a unique UUID.


This will erase the drives, so to save what is currently on them, I suggest that you connect them one at a time & clone their contents to another drive (obviously one with a different UUID!), reformat them, & then clone back their contents.

Oct 8, 2013 11:16 AM in response to markmal

markmal wrote:


OK, i've been having a lot of problems lately with backup software (superduper! and time machine in particular), as well as itunes, where the apps seem to be confused about which external hard drive is which. this has had messy and in some cases disasterous results. after digging around a bit, i've discovered that an external hd (western digital 2t) connected directly to my mac, as well as three other hds (all western digital 2t drives) connected through a hub (anker usb 3.0 powered hub), have identical uuids.


anyone know why this happens? and what i can do to correct it?


thanks!

As R C-R says I posted about this in the Level 6+ forum a few months ago.


I think all you can do for now is reformat prior to using them - I didn't notice until each one started being used as a Time Machine Backup when I'd only intended the first to be used for that.


You may wish to contact WD support - I nearly did at the time but didn't as you seemed to need to register to contact them and I was looking for a more straightforward contact method.


AC

Nov 4, 2015 8:02 AM in response to Alley_Cat

Hi,

Does this issue happen with different manufacture's external HDD drive?

I have 2 WD external HDDs (4TB - MyBook) and 3 Seagate external HDD (2TB - seagate). I did not plan to buy a lot of external HDDs, but unfortunately, I had to do.


I need to replace my iMac's internal HDD and I purchased WD external HDD (4TB) and I used this one for back-up through Time Machine. And 2nd WD external HDD, I planed to use just back-up documents and multimedia files b/c Time Machine takes a lot of time to back-up. I want to save time so I need the 2nd HDD to back-up for only selected files. And suddenly, some day, after I copied some file into the 2nd WD external HDD, all data of the 2nd WD HDD were erased when I connected it - and it was formatted HFS+.

I guess the cause of the identical UUIDs of both WD external HDD. First WD HDD was formatted by Time Machine, but the 2nd WD HDD was not - just factory default as NTFS.


I tried to recover the data on the 2nd WD external HDD, but my internal HDD did not have enough space, that was why I had to purchase another external HDD - Seagate 2TB external HDD.


But, you know, data of Seagate 2TB external HDD was erased again and it was formatted HFS+. And Mac OS detected the Seagate HDD as MyBook (WD). How can this happen?


I have done data recovery process several times and it happened again last night - even I turned off Time Machine feature. Since data on the 2nd WD external HDD was erased by something (Time Machine or whatever), I have not connected any WD external HDDs into my iMac, but how Mac OS said WD external HDD was connected when the Seagate external HDD was connected?


I am so tired to recover the erased data again and again. I need to finish to back-up of data from internal HDD before end of this year. Please help me to avoid this happening again.


Thank you.

Help! Multiple Hard Drives with Identical UUIDs!

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