Mirror spinning disk to SSD?



  • I had an HPE drive fail in a server under warranty. I don't have the drive in hand yet, but the field tech told me that the replacement drive is a 1TB SSD. The old drive was a 1TB mechanical. The drives were mirrored.

    Can I swap out a HDD for a SSD, let it mirror and then swap out the other HDD? I know in general you want the drives to be identical, and everything will slow down to the HDD, but since it's for a one time mirror, it seems like it could work.



  • You can do so, the only issue is the mirror will only operate as fast as that mechanical drive.

    So it'll be slow.



  • @DustinB3403 said in Mirror spinning disk to SSD?:

    You can do so, the only issue is the mirror will only operate as fast as that mechanical drive.

    So it'll be slow.

    I agree -- It will be as fast as it's slowest part... But as long as it is:

    • equal in size
    • same interface

    It should be perfectly fine.


  • Banned

    Yes it will work and be fine.

    The dumb thing is that HPE would waste a 1TB SSD at triple the price when a mechanical would be fine.



  • If it actually is two SSDs they will be worth more than the server they are going in. (It's a little HPE microserver.)



  • @Mike-Davis said in Mirror spinning disk to SSD?:

    If it actually is two SSDs they will be worth more than the server they are going in. (It's a little HPE microserver.)

    Great 😃



  • @gjacobse said in Mirror spinning disk to SSD?:

    @DustinB3403 said in Mirror spinning disk to SSD?:

    You can do so, the only issue is the mirror will only operate as fast as that mechanical drive.

    So it'll be slow.

    I agree -- It will be as fast as it's slowest part... But as long as it is:

    • equal in size
    • same interface

    It should be perfectly fine.

    Replacement drive can be bigger (not that it's going to use that space).



  • @Kris_K said in Mirror spinning disk to SSD?:

    @gjacobse said in Mirror spinning disk to SSD?:

    @DustinB3403 said in Mirror spinning disk to SSD?:

    You can do so, the only issue is the mirror will only operate as fast as that mechanical drive.

    So it'll be slow.

    I agree -- It will be as fast as it's slowest part... But as long as it is:

    • equal in size
    • same interface

    It should be perfectly fine.

    Replacement drive can be bigger (not that it's going to use that space).

    Quite right,.. thanks for pointing that out. To early in the day, Not enough coffee.



  • If HPE is the one doing the part swap, you can be pretty sure it will work. Of course, they've not had the best track record with 3PAR as of late. But I digress. But the new drive in any RAID array must be equal or larger. Equal is a real thing, you can't round. So 1TB of SSD needs to be not "close enough to call it 1TB" but actually equal or bigger.


  • Vendor

    @Mike-Davis said in Mirror spinning disk to SSD?:

    I had an HPE drive fail in a server under warranty. I don't have the drive in hand yet, but the field tech told me that the replacement drive is a 1TB SSD. The old drive was a 1TB mechanical. The drives were mirrored.

    Can I swap out a HDD for a SSD, let it mirror and then swap out the other HDD? I know in general you want the drives to be identical, and everything will slow down to the HDD, but since it's for a one time mirror, it seems like it could work.

    You'd better run your workload on SSD and use HDD as a backup destination. Mirroring SSD + HDD isn't going to make anybody any good: speed of a fleet is limited with a slowest ship in it (read - HDD in our context).



  • So HP shipped Enterprise HDDs instead of the desktop labeled drives they had in there from the factory. It took a few hours to mirror each drive and it was totally uneventful. - which is exactly what you're looking for in these types of things.


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