vSAS - Value Serial Attached SCSI



  • Anyone have any opinions on using vSAS in a production server, non Cluster, simple file sharing and printer serving.



  • @JasGot said in vSAS - Value Serial Attached SCSI:

    Anyone have any opinions on using vSAS in a production server, non Cluster, simple file sharing and printer serving.

    Do you mean "virtual" instead of "value"?

    vSAS is just another term for vSAN. And like all SAN without a cluster, it really has no purpose. It's not that it won't work, the question is, though... why? What purpose would it serve?



  • From Dell:
    Toshiba Memory Corporation, an independent spin-off company of Toshiba, created vSAS, short for Value Serial Attached SCSI, to be the storage technology capable of completely phasing out the SATA (Serial Advanced Technology Attachment) interface for SSDs. The transition to SAS-only has been slow because traditional SAS SSD drive pricing has typically been higher than SATA SSD drive pricing. Despite its throughput limitations, SATA proved to be the most cost-effective way to build dense server storage.

    https://downloads.dell.com/manuals/common/dfd-value_sas_future_rplcmt_for_sata_ssd.pdf



  • @JasGot said in vSAS - Value Serial Attached SCSI:

    From Dell:
    Toshiba Memory Corporation, an independent spin-off company of Toshiba, created vSAS, short for Value Serial Attached SCSI, to be the storage technology capable of completely phasing out the SATA (Serial Advanced Technology Attachment) interface for SSDs. The transition to SAS-only has been slow because traditional SAS SSD drive pricing has typically been higher than SATA SSD drive pricing. Despite its throughput limitations, SATA proved to be the most cost-effective way to build dense server storage.

    https://downloads.dell.com/manuals/common/dfd-value_sas_future_rplcmt_for_sata_ssd.pdf

    They made a new tech that replaces an old tech with the same acronym? That's a poor chose of naming. And like... what does "value" mean there? Facepalm.



  • Oh, it literally isn't a technology, it's Toshiba's marketing name for their "cheap SAS". facepalm again.

    "Toshiba Memory Corporation has introduced the RM5-series value SAS SSD: a unique storage drive with
    SAS interface that will be priced close to typical SATA pricing. To reduce the total cost Toshiba Memory thoughtfully simplified the architecture of value SAS; low-impact, non-critical features were removed from the typical SAS SSD."

    So it's not a tech, it's just a Toshiba product line of midrange SSDs. Not high end like NVMe drives, and not quite as good as standard SAS SSD, but better than SATA SSD.

    I mean, seems like a fine idea. If a SATA SSD was the alternative, this seems like an improvement.



  • This sounds like vSAS is the SSD equivalent of NL-SAS: both are just general purpose marketing terms and not names of any specific technology. Just "SAS devices intended for near line use."



  • Just a marketing thing.

    NVMe is the king of enterprise SSDs and what you should use whenever possible. But you can also use enterprise SATA when you don't need blazing fast performance but the same reliability.

    What Toshiba is proposing is that in these situations where you don't need the highest performance you might as well skip SATA and use SAS instead and get the advantage of 12 Gbps interface. The value part I'm guessing is just how they will price themselves towards other SAS drives.

    https://www.datacenterknowledge.com/industry-perspectives/why-new-class-ssd-needed



  • @Pete-S said in vSAS - Value Serial Attached SCSI:

    The value part I'm guessing is just how they will price themselves towards other SAS drives.

    What they claim is that they stripped out a bunch of the higher end features that people assume are on the SAS drives, but aren't on SATA. But no one should assume that, it was a false assumption. Which is exactly what NL-SAS was, too. So once said and done, these are just Toshiba SAS drives.



  • @scottalanmiller said in vSAS - Value Serial Attached SCSI:

    @Pete-S said in vSAS - Value Serial Attached SCSI:

    The value part I'm guessing is just how they will price themselves towards other SAS drives.

    What they claim is that they stripped out a bunch of the higher end features that people assume are on the SAS drives, but aren't on SATA. But no one should assume that, it was a false assumption. Which is exactly what NL-SAS was, too. So once said and done, these are just Toshiba SAS drives.

    The only thing I can think of that they can strip out is the dual port interface.

    But still SAS is legacy tech. Don't know why they even bother.



  • @Pete-S said in vSAS - Value Serial Attached SCSI:

    @scottalanmiller said in vSAS - Value Serial Attached SCSI:

    @Pete-S said in vSAS - Value Serial Attached SCSI:

    The value part I'm guessing is just how they will price themselves towards other SAS drives.

    What they claim is that they stripped out a bunch of the higher end features that people assume are on the SAS drives, but aren't on SATA. But no one should assume that, it was a false assumption. Which is exactly what NL-SAS was, too. So once said and done, these are just Toshiba SAS drives.

    The only thing I can think of that they can strip out is the dual port interface.

    But still SAS is legacy tech. Don't know why they even bother.

    Can you hot swap NVMe? Is their a backplane solution for NVMe? These might be reasons... plus cost is still a reason assuming NMVe's are noticeably more expensive.



  • @Dashrender said in vSAS - Value Serial Attached SCSI:

    @Pete-S said in vSAS - Value Serial Attached SCSI:

    @scottalanmiller said in vSAS - Value Serial Attached SCSI:

    @Pete-S said in vSAS - Value Serial Attached SCSI:

    The value part I'm guessing is just how they will price themselves towards other SAS drives.

    What they claim is that they stripped out a bunch of the higher end features that people assume are on the SAS drives, but aren't on SATA. But no one should assume that, it was a false assumption. Which is exactly what NL-SAS was, too. So once said and done, these are just Toshiba SAS drives.

    The only thing I can think of that they can strip out is the dual port interface.

    But still SAS is legacy tech. Don't know why they even bother.

    Can you hot swap NVMe? Is their a backplane solution for NVMe? These might be reasons... plus cost is still a reason assuming NMVe's are noticeably more expensive.

    Yes, you can hostswap NVMe. Yes, backplane is what is commonly used, for instance 2.5" U.2 drives.

    NVMe drives are not really more expensive unless they are being marked up by the middle man.
    For instance we pay exactly the same price for 1.92TB Samsung PM883 SATA as for the 1.92TB Samsung PM983 U2/NVMe, about $360.

    It's the same class of drive from the same manufacturer but the NVMe version is much faster (540K IOPS vs 98K on random read).



  • @Pete-S said in vSAS - Value Serial Attached SCSI:

    PM983

    Cool, I just haven't seen or looked into these at all, figured they must be coming... thanks.

    As for the prices you listed - are these "consumer grade" vs enterprise grade gear? is the MTBF on par with Enterprise gear, warranties, etc?



  • @Dashrender said in vSAS - Value Serial Attached SCSI:

    @Pete-S said in vSAS - Value Serial Attached SCSI:

    PM983

    Cool, I just haven't seen or looked into these at all, figured they must be coming... thanks.

    As for the prices you listed - are these "consumer grade" vs enterprise grade gear? is the MTBF on par with Enterprise gear, warranties, etc?

    No, they are not consumer drives, they are enterprise drives. But they are at the low end in their segment.
    As you can see the msrp is $379.99 for both.

    https://www.samsung.com/us/business/products/computing/ssd/enterprise/883-dct-1-9tb-mz-7lh1t9ne/
    https://www.samsung.com/us/business/products/computing/ssd/enterprise/983-dct-1-9tb-mz-qlb1t9ne/



  • @Pete-S said in vSAS - Value Serial Attached SCSI:

    For instance we pay exactly the same price for 1.92TB Samsung PM883 SATA as for the 1.92TB Samsung PM983 U2/NVMe, about $360.
    It's the same class of drive from the same manufacturer but the NVMe version is much faster (540K IOPS vs 98K on random read).

    Yeah, it's really just one connector or the other connector (okay, there's some logic different in the chips, but you know what I mean.) It's like which should cost more, your laptop connected to ethernet or your laptop on wifi? Same laptop, just which adapter is being used. One is much faster, but they don't cost different amounts.



  • @scottalanmiller said in vSAS - Value Serial Attached SCSI:

    @Pete-S said in vSAS - Value Serial Attached SCSI:

    For instance we pay exactly the same price for 1.92TB Samsung PM883 SATA as for the 1.92TB Samsung PM983 U2/NVMe, about $360.
    It's the same class of drive from the same manufacturer but the NVMe version is much faster (540K IOPS vs 98K on random read).

    Yeah, it's really just one connector or the other connector (okay, there's some logic different in the chips, but you know what I mean.) It's like which should cost more, your laptop connected to ethernet or your laptop on wifi? Same laptop, just which adapter is being used. One is much faster, but they don't cost different amounts.

    I "feel" there's some huge assumptions here... why do you assume that ethernet chips cost the same as WiFi chips?
    I'd ask the same about SAS vs NVMe chips... I mean, of course they might not cost different, but then again, they would be wildly apart.



  • @Dashrender said in vSAS - Value Serial Attached SCSI:

    I "feel" there's some huge assumptions here... why do you assume that ethernet chips cost the same as WiFi chips?

    Because they do, they are all within like a couple cents of each other. And more importantly, both are already there. Just like on the SAS controller. The hardware is almost all "already there", it just which one you use that changes.



  • @Dashrender said in vSAS - Value Serial Attached SCSI:

    I'd ask the same about SAS vs NVMe chips... I mean, of course they might not cost different, but then again, they would be wildly apart.

    For all intents and purposes, all networking connection interfaces cost roughly the same. Maybe NVMe costs $.25 and SAS costs $.20. It's all pennies and background noise when talking about this stuff. Totally meaningless in the pricing model.

    The reason that an NVMe drive costs more than a SAS drive typically is because one is a high end screaming fast drive, and the other is not.

    Just like SAS and SATA. The cost difference to make them was trivial, nominal or even non-existant. So cheap that normally both were always there, what changed is which was turned on, not which you paid for.


  • Vendor

    @Dashrender said in vSAS - Value Serial Attached SCSI:

    Can you hot swap NVMe?

    Yes. There's basically 2 ways. Intel VMD, and the NVMe spec for hotswap. It's a work in progress but yes, it's not impossible. Our HCLlists which NVMe drives we support it with

    Is their a backplane solution for NVMe?

    There are backplanes that can take EITHER NVMe or SAS drives (HPE has them). Note, U.2 generally just plug straight NVMe to PCI-E bus, but there are crossbar solutions (There were a few hundred bucks last I saw, but they exist).

    These might be reasons... plus cost is still a reason assuming NMVe's are noticeably more expensive.

    There are Cheaper QLC NVMe drives, and there are high endurance eMLC SAS drives that will out perform them on writes. Don't confuse an interface for a drive speed.


  • Vendor

    @Dashrender said in vSAS - Value Serial Attached SCSI:

    I'd ask the same about SAS vs NVMe chips... I mean, of course they might not cost different, but then again, they would be wildly apart.

    100% of the time a SAS drive needs a SAS HBA or RAID Controller to speak to a CPU (and possibly a SAS expander). In 90% of the NVMe configs you see, a NVMe drive talks straight to the PCI-E bus and the CPU so this is apples/oranges.



  • @StorageNinja said in vSAS - Value Serial Attached SCSI:

    100% of the time a SAS drive needs a SAS HBA or RAID Controller

    Because the RAID controller is actually a tiny computer with its own built on SAS HBA 🙂


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