Some databases (Postgres, MySQL) have gotten good performance
increases by treating their backends more as storage controllers than
as simple file access. This leads to some strange performance
degradation on filesystems like ZFS, which also work similarly to a
database, but can not optimize access based on data content.
So it is not always knowledge of the physical media that counts.
On Mon, Apr 9, 2018 at 9:36 AM, xxxxx@gmail.com
wrote:
> Actually if I recall correctly the adapter port drivers in windows had or
> have some sort of scheduling mechanism, not sure if they still do. It
> remains lame. The agents that understand how a specific disk hardware
> operates are the agents closest to the disk hardware, generally the firmware
> on the disk itself or in cases where the disks are tightly coupled to the
> adapter(s), the adapter firmware.
>
> Mark Roddy
>
> On Mon, Apr 9, 2018 at 10:11 AM, xxxxx@gmail.com
> wrote:
>>
>> There is quite a bit of interest in kernelspace reordering on Linux, which
>> is what I was trying to refer to. For various reasons the firmware based
>> optimizations are insufficient. So, if Windows does no optimizations, I
>> think that answers my question.
>>
>>
>> On Mon, Apr 9, 2018 at 8:40 AM, xxxxx@windrvr.com
>> wrote:
>> > 20 years or so for drives, some disk controllers were doing this over 35
>> > years ago.
>> >
>> >
>> >
>> >
>> >
>> > Don Burn
>> >
>> > Windows Driver Consulting
>> >
>> > Website: http://www.windrvr.com
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > From: xxxxx@lists.osr.com
>> > [mailto:xxxxx@lists.osr.com] On Behalf Of
>> > xxxxx@gmail.com
>> > Sent: Monday, April 09, 2018 9:31 AM
>> > To: Windows System Software Devs Interest List
>> > Subject: Re: RE:[ntdev] Interaction of File Systems with Bulk Disk
>> > Access
>> >
>> >
>> >
>> > Where “modern” is like at least the last 20 years or so.
>> >
>> >
>> > Mark Roddy
>> >
>> >
>> >
>> > On Sun, Apr 8, 2018 at 7:31 PM, xxxxx@ramsystems.biz
>> > wrote:
>> >
>> > Yep, modern drives do all this internally. Hence command queuing.
>> >
>> > * Bob
>> >
>> >
>> > Bob Ammerman
>> > xxxxx@ramsystems.biz
>> > 716.864.8337
>> >
>> > 138 Liston St
>> > Buffalo, NY 14223
>> > www.ramsystems.biz
>> >
>> >
>> >
>> > -----Original Message-----
>> > From: xxxxx@lists.osr.com
>> > On Behalf Of xxxxx@osr.com
>> > Sent: Sunday, April 8, 2018 7:28 PM
>> > To: Windows System Software Devs Interest List
>> > Subject: RE:[ntdev] Interaction of File Systems with Bulk Disk Access
>> >
>> >
>> >
>> > We call that ?seek optimization? ? I?ve written a whole lot of that code
>> > in
>> > my career… but none for hard drives in the last decade plus. In my
>> > experience, this type of optimization is seriously out of date, because
>> > we
>> > can no longer guess at the true geometry of the drive. So, ?nearest
>> > sector
>> > first? and ?elevator service / next sector first? based on Starting LBA
>> > are
>> > no longer very effective. Windows has never had any such code in the OS
>> > (though it is entirely possible that one or two of the original disk
>> > drivers
>> > ? maybe the floppy driver ? MAY have had such code in them at some
>> > point. I
>> > don?t remember). But I can authoritatively tell you that no such code
>> > exists in Windows today.
>> >
>> > Peter
>> > OSR
>> > @OSRDrivers
>> >
>> >
>> >
>> >
>> > —
>> > NTDEV is sponsored by OSR
>> >
>> > Visit the list online at:
>> > http:
>> >
>> > MONTHLY seminars on crash dump analysis, WDF, Windows internals and
>> > software
>> > drivers!
>> > Details at http:
>> >
>> > To unsubscribe, visit the List Server section of OSR Online at
>> > http:
>> >
>> > —
>> > NTDEV is sponsored by OSR
>> >
>> > Visit the list online at:
>> > http:
>> >
>> > MONTHLY seminars on crash dump analysis, WDF, Windows internals and
>> > software
>> > drivers!
>> > Details at http:
>> >
>> > To unsubscribe, visit the List Server section of OSR Online at
>> > http:
>> >
>> >
>> >
>> > — NTDEV is sponsored by OSR Visit the list online at: MONTHLY seminars
>> > on
>> > crash dump analysis, WDF, Windows internals and software drivers!
>> > Details at
>> > To unsubscribe, visit the List Server section of OSR Online at
>> >
>> >
>> > —
>> > NTDEV is sponsored by OSR
>> >
>> > Visit the list online at:
>> > http:
>> >
>> > MONTHLY seminars on crash dump analysis, WDF, Windows internals and
>> > software
>> > drivers!
>> > Details at http:
>> >
>> > To unsubscribe, visit the List Server section of OSR Online at
>> > http:
>>
>> — NTDEV is sponsored by OSR Visit the list online at: MONTHLY seminars
>> on crash dump analysis, WDF, Windows internals and software drivers! Details
>> at To unsubscribe, visit the List Server section of OSR Online at
>
>
> — NTDEV is sponsored by OSR Visit the list online at: MONTHLY seminars on
> crash dump analysis, WDF, Windows internals and software drivers! Details at
> To unsubscribe, visit the List Server section of OSR Online at</http:></http:></http:></http:></http:></http:></http:></http:></http:>