Pegasus32 Discussions

Drives failing and blue lights

2026-05-11T02:13:53.7130000

This four year old Pegasus 32 drive has been perfect up until yesterday.

Now when i turn it on only the top four drives have both blue lights on, the second four drives have only one blue light on. The power button stays red and the iMac Pro doesn't see the drive at all.

The drive is connected to an iMac Pro 2018 running OS 15.6.1 Sequoia. I've run Promise Utility (new and old) Disk Utility, Disk Warrior and Disk Drill and none of them see it. Ive changed cables and cleaned all ports.

I would normaly assume drive failure but I find it hard believe four drives would all die on the same day?

It was set up Raid 0 - as recommended for my use.

Would anyone have any suggestions? I am at the end of my diagnostic capabilities. Any help would be more than welcome. Thanks

A painful lesson: I may have DESTROYED my own Pegasus RAID system

2026-06-20T06:13:43.9670000

Hi everyone,

I just wanted to share a personal experience that happened to me recently, hoping it may help someone avoid the same mistake.

I recently bought a 320W replacement power supply for my Promise Pegasus3 from KDMpower on eBay. I was honestly very excited because my Pegasus unit had been powered off for a while (due to power supply failure), and I was looking forward to finally bringing it back to life.

Unfortunately, the worst possible thing happened.

I did not realize that this replacement power supply has a small but very important switch on the back to select the input voltage: 110V or 230V. I assumed it would work like the original Promise power supply, which does not have this kind of switch. Because of that, I plugged it directly into my 220V power source without noticing that the replacement unit was set to 110V by default.

As soon as I powered it on, I heard a loud “pop pop” sound, followed by smoke coming from the drive system.

It was honestly terrifying.

At this point, I still do not know exactly what was damaged. I am hoping that only the power supply was burned, but I am also worried that something else inside the Pegasus unit — or even the drives — may have been affected. For anyone who stores important data on a RAID system, you probably understand how scary that moment feels.

I want to be very clear: I am not writing this to blame the seller or the manufacturer. This was partly my mistake because I did not check carefully enough before plugging it in.

But at the same time, I think this is something that should be made much more obvious to buyers. Not everyone is an electrician or a technical expert. Some of us are just regular users trying to replace a failed power supply and get our system running again. I honestly did not even know this kind of voltage switch existed until the problem happened.

So my advice is simple:

Before using any replacement power supply, especially one bought from a third-party seller, please check whether it has a 110V / 230V input voltage selector. Do not assume it works the same way as the original part.

If you are in a 220V / 230V country and the power supply is set to 110V, plugging it in directly can cause serious damage instantly.

Now, I really need some advice from a technician or electrical expert here.

I honestly do not know what may have happened to my system. Is there a chance that the mainboard of the Pegasus enclosure was damaged? Could the hard drives themselves also be affected, or is it more likely that only the power supply failed?

What should I do next? Should I try buying another replacement power supply and test it again, or should I avoid powering the unit on completely until it has been inspected by someone qualified?

I am quite confused and worried at the moment, so I would really appreciate any guidance from anyone who has experience with this kind of issue.

Thank you so much for your help.

Long Shot, But trying to see why I am experiencing slow downs on Pegasus32 and Browser Crashes

2026-06-11T01:52:18.3100000

Ever sence moving from Intel Mac to Mac Studios I have run into some interesting issues that I have been unable to solve.

1. Speeds on Promise Pegasus32 R6 have been subpar based on the TB3 standard from what I can really gather. I at best see around 550 - 800MB/s Writes and 450 - 750MB/s Read. I almost see these similar speeds with USB-C 10Gbps. I have tried numerous cables (active and passive).

2. And this is a extremely weird one. (Don't have this at all when using USB-C Drives Directly) When attempting to write files to the PP32 from lets say chrome or safari, it will just end up circle of death and crash the browsers to halt, then I have to force quit, but after that I must reboot as it will just happening again sooner and sooner.

I have been able to replicate this by saving indivdual files, like photos, one after another and then it will cause the halt, this could freeze the browser for 2 - 10 mins then maybe I will be able to save again to the PP32 for a few more times before it happens again and must reboot.

One thing I do notice is that the process of "Open and Save Panel Service" for lets say google does fail and error out, but it seems like the system is either way too fast and cannot catch up or extremely slow.

I have seen some talk about "If a RAID volume has a 16kB stripe size, it is known to cause kernel panics on M-series chips. You may need to back up your data and reformat the array using a 64kB stripe unit size (or convert to a RAID 4/5)" and wonder if there is something here on my end.

I know its a long shot and a lot there, but I have been at this for a long time trying to figure this out, from M1 to M4, just seems I am having issues directly with Pegasus in general and its not happy with Apple Silicone. (Purchased a new M4 fresh out of box thinking it would solve issues and its the same thing.)

Update: as of writting this, I tested brand new TB4/5 Active cables and saw same read and write speeds above. Randomly grabbed a passive TB4 Cable and seeing speeds now reach 1100-MB/s Read and 770MB/s Write which seems to be more aligned with expectations for TB3 and RAID5. Not sure why the actives are reverting to USB speeds as the run is over 3 meters, but it is interesting.

Promise32 R6 just died

2025-05-14T13:15:09.1370000

Today I noticed that our Promise32 R6 with 24TB and around 16TB of data on it does not show up on our Mac Mini Server any more. Upon inspection and unplugging the unit for a few minutes, it is just completely dead. No light comes on at all, no sounds can be heard from it.

Of course this comes 6 months after the warranty has expired.

Is there anything we can do? I find it hard to believe that a >$3K hard drive just fails like that.

Are there any fuses inside, that might get triggered? Can we get it repaired?

Thanks for any hints.

Mounting Issues - Promise Pegasus 32 R4 to a M1 Macbook Pro

2026-04-15T18:31:35.7000000

Hi there

I am havina problem with my Pegasus 32 R4. When I plug it into my Mac using the Thunderbolt 3 cable, all the blue lights come on and the Pegasus 32 R4 is whirring to show that it is working. However, when I look in Finder, there is no sign of it and no sign of it in the disk utility either. Please help!

Careful Updating Mac OS to 26.4 (Beta) - R32 "can't repair" Warning

2026-02-19T07:44:04.3870000

Just recently updated to macOS Tahoe 26.4 Beta (25e5207k). After update and reboot, errors popped up "macOS can’t repair the disk “Pegasus32”.

Both my systems can only be read and cannot write, repair or anything at this point.

Might be isolated, but no issues on other systems not on this beta.

Promise Utility Pro Version 24.5.7

2026-02-19T17:47:21.0270000

Hello. How come Promise Utility Pro version 24.5.7 isn't available as a stand-alone download? I get an update prompt through the application but can't find it--or really any mention of it anywhere--on the site. Was it removed because of a problem? Is it a Beta? What's the story?

Thanks.

-Doug

SSD Wizard Configuration

2025-12-15T13:34:05.1370000

Hello, I am planning to upgrade my Pegasus32 R4 with SSD drives.

I was wondering if there are any special considerations to take into account when configuring the disk array and logical drive, or any recommended parameters for using the enclosure with SSDs.

I am also wondering if it is necessary to enable a TRIM function in some way, or if everything is handled automatically.

My operating system is Mac OS Sonoma.

Can't access my promise pegasus32 after upgrading to macos Tahoe

2025-10-23T08:36:27.7930000

Hii

i can't access my promise pegasus32 R8 after upgrading to macos tahoe - I have it running on my mavbook pro M1.

Anybody knows what to do ??

Having Issues Creating Disc Array

2025-09-18T01:35:23.2900000

Has anyone had trouble having the 'start disc array' show up on Promise Utility Pro? I just got all new drives for more capacity on my 32r8, the drives show up but in my Promise Utility Pro I don't see any option to set as a RAID5. I reformatted all the drives for mac and they show up as 'passthrough drives'. Thanks to anyone in advance!

-L

Email Alerts

2025-06-19T21:18:35.9870000

Are email alerts available using Promise Utility Pro with Pegasus32 on macOS? Don;t see any way to set them, and nothing in the manual.

Have used Pegasus RAIDs on macOS for years and the email alerts have proved pretty useful in the past.

HFS+ or APFS for RAID10 on MailServer with M2Pro Mac Mini

2025-06-18T14:45:08.8770000

Hi,

I have a new Pegasus32 R8 32TB connected to a Mac mini M2 Pro running macOS Sequoia?

Any guidance on whether to use APFS or HSF+ formatting for Raid 10

Many thanks,

ft.

Pegasus 32 powers UP drives on own while Mac Studio 4 MAX is in sleep mode

2025-05-28T16:23:59.5300000

Brand new Mac Studio and new Pegasus 32 (64 TB). All operational and installed correctly. Quite often, Pegasus drives spin up and eight blue drive lights on enclosure start the flicker, as if copying data. Drives then power down (fan continues to run for some time) then process begins again at some point later. Mac is in sleep mode (low power state, display off, even though it may perform some tasks in background.) Online forums report similar issues but typically involve Pegasus 2 and 3 units. If you have experience with this this issue with the 2024-2025 Mac Studio, suggestions are welcome. See Mac attached energy settings.

Pegasus32 R4 - Upgrade Hard Drives

2025-05-07T01:40:04.3200000

Hi,

Looking for some guidance on how to replace my hard drives in the Pegasus32 R4. I previously had a couple drobo and could pretty easily figure out how to replace drives. I recently moved to Pegasus in the last few years, and of course have run out of available space.

This link on the main page makes it seem like there's just a couple of drives that will work, Promise SATA Hard Drive Compatability.

Going on microcenter, I'm looking at updating the 4 hard drives from their current 4tb to 10tb each, I read in other posts all the hard drives need to be the same size so I plan on getting 4.

How do you know which drives to get that'll work? Toshiba N300 10TB 7200 RPM SATA III 6Gb/s 3.5" Internal CMR NAS Hard Drive - Mfr Part#: HDWG71AXZSTA - For example, this drive isn't on the list but the brand and sizing looks right.

Appreciate any pointers on how to move forward finding compatable drives, and especially how to perform the drive swap, & update process.

Mac Studio M3 Ultra

2025-03-27T16:09:27.4500000

Did anyone succeed in mounting the Pegasus 32 R 4 on he new Mac Studio M3 Ultra?

I did install DEXT, but did not succeed so far. The Mac 'sees' the Pegagus in System Report.

Fimware of the Pegasus: 6.04.0000.18

(not the lates - but unfortunately, the disk image of 6.0.6 is corrupted on this website)