P3R4 4TB per drive Capacity Limit

Pradeep Chidambaranath posted this 30 May 2018

Hi Danor,

Kindly go to the link below to access our estore link to Build to Order Pegasus3 unit\ with higher size drives.

https://estore.promise.com/us/product/bto/pegasus3

Regards
Pradeep C

Danor Gerald posted this 30 May 2018

Thanks Pradeep,

Does this mean that I can't use larger capacity hard drives in my existing Pegasus3 model? I already purchased a 4x4 unit, but I want to swap out those original drives for new ones since they are full of video footage. I was just wondering if I could swap in 5 or 6TB hard Drives instead. It says they are swappable on the site but is there a capacity limit for some reason?

Doesn't seem like there should be but I want to know before I buy the next set of drives to fill the Pegasus for another project.

Thanks,

Danor

Danor Gerald posted this 30 May 2018

Thanks for your quick response by the way.

Pradeep Chidambaranath posted this 30 May 2018

Hi Danor,

The maximum size drive support on a Pegasus 3 unit is 14TB. You can swap out the existing 4TB drives with higher capacity compatible drives. Kindly go to the link below to download the compatiblity list.

https://promise.com/DownloadFile.aspx?DownloadFileUID=4834

Regards
Pradeep C

Danor Gerald posted this 30 May 2018

Awesome! Thanks for confirming!

Pradeep Chidambaranath posted this 30 May 2018

Hi Danor,

You are more than welcome. Also, please note that when you replace the drive with higher size drive, you have to replace all the drive at once and create a new disk array and logical drive. When you replace one drive at a time to rebuild the data, the higher size drive will be read only as a 4TB drive.

Kindly go to the link below to access our KB article on how to create a new volume.

https://kb.promise.com/thread/how-do-i-create-a-volume-on-a-pegasus/

Regards
Pradeep C

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Danor Gerald posted this 30 May 2018

Great! Excellent Customer Service!

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Matthew Deery posted this 07 December 2025

I am looking to swap out my 4TB drives P3R4 unit. Is there a process to getting this done correctly? Is there a how-to on this somewhere? All drives swapped out at once vs. one by one?

And 14TB is the max per drive? And do all the drives need to be the same size? Or can some be larger and some smaller?

Hi Danor,

The maximum size drive support on a Pegasus 3 unit is 14TB. You can swap out the existing 4TB drives with higher capacity compatible drives. Kindly go to the link below to download the compatiblity list.

https://promise.com/DownloadFile.aspx?DownloadFileUID=4834

Regards
Pradeep C

Admin

Frank Bosma posted this 08 December 2025

Hi Matthew,

the latest version compatibility list for the Pegasus3 device shows tested HDDs up to 24TB.
https://www.promise.com/DownloadFile.aspx?DownloadFileUID=7459
In theory you can use any SATA HDD or even SSD in the Pegasus3 devices, there is no hardware or software limitations for any specific brand or type of HDD, however we recommend using the disks in the compatibility list since we can guarantee correct functionality.

It is possible to use a combination of different size HDDs in one array, however the total capacity of your array will be 4x the capacity of the smallest capacity disk in your system, the rest of the space on your larger disk(s) will then be void.

Regarding the process of swapping out the disks;
by far the easiest and safest way is to create a backup of all data on your current set of disks, then simply swap all disks at once and create a new array and logical drive in the Promise utility.
If you use the wizard's automatic configuration option it will automatically create a default RAID5 setup and mount it on your machine.

If you can not do this and need to enlarge your logical drive by replacing disks individually then you can follow the process described by Babatunde on our knowledgebase. Please note that this is a very time consuming process and not without risks.
https://kb.promise.com/thread/increasing-the-storage-capacity-of-a-pegasus-lun-by-rebuilding-with-larger-drives/

Kind regards,
Frank

Matthew Deery posted this 2 weeks ago

Hey Frank,

I bought drives from the recommend list, four 20TB Exos X24. I just installed them into my Pegasus3 R4. The drive turns on, the lights all flash blue, but it is not being recognized by the Promise Utility App and the drive is beeping about every 5 seconds.

Any thoughts on a remedy?

Hi Matthew,

the latest version compatibility list for the Pegasus3 device shows tested HDDs up to 24TB.
https://www.promise.com/DownloadFile.aspx?DownloadFileUID=7459
In theory you can use any SATA HDD or even SSD in the Pegasus3 devices, there is no hardware or software limitations for any specific brand or type of HDD, however we recommend using the disks in the compatibility list since we can guarantee correct functionality.

It is possible to use a combination of different size HDDs in one array, however the total capacity of your array will be 4x the capacity of the smallest capacity disk in your system, the rest of the space on your larger disk(s) will then be void.

Regarding the process of swapping out the disks;
by far the easiest and safest way is to create a backup of all data on your current set of disks, then simply swap all disks at once and create a new array and logical drive in the Promise utility.
If you use the wizard's automatic configuration option it will automatically create a default RAID5 setup and mount it on your machine.

If you can not do this and need to enlarge your logical drive by replacing disks individually then you can follow the process described by Babatunde on our knowledgebase. Please note that this is a very time consuming process and not without risks.
https://kb.promise.com/thread/increasing-the-storage-capacity-of-a-pegasus-lun-by-rebuilding-with-larger-drives/

Kind regards,
Frank

Admin

Frank Bosma posted this 2 weeks ago - Last edited 2 weeks ago

Hi Matthew,

Power down the device, remove all disks from the housing, then boot up without any disks.

Check if the unit can be seen in the utility.

Now insert disk #1 while powered on and check if it is shown in the utility, this might take a little while. It should show up in the physical drive overview and have status unconfigured, if not change it in settings.

Repeat with the remaining disks.

Matthew Deery posted this 6 days ago

Thanks Frank. This worked for the first three drives. For the fourth one is just makes some noises as it boots up, beeps, and the drive never connects to the computer. Could this be a drive error or something else that needs to be remedied?

Hi Matthew,

Power down the device, remove all disks from the housing, then boot up without any disks.

Check if the unit can be seen in the utility.

Now insert disk #1 while powered on and check if it is shown in the utility, this might take a little while. It should show up in the physical drive overview and have status unconfigured, if not change it in settings.

Repeat with the remaining disks.

Admin

Frank Bosma posted this 6 days ago

That sounds like an issue with that specific HDD.
To be sure you can test it again in one of the other slots in your Pegasus device, just to clarify if the issue is caused by the disk itself or the slot/backplane of the Pegasus device.

Obviously, if the issue remains with the disk itself then you can exchange it for a good one.

P3R4 4TB per drive Capacity Limit

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