Very low disk performance on 5.x

Poul-Henning Kamp phk at phk.freebsd.dk
Mon May 2 07:37:41 PDT 2005


In message <42763906.1040202 at centtech.com>, Eric Anderson writes:
>> In message <6.2.1.2.2.20050502094757.037077f0 at mail.rfnj.org>, Allen writes:
>> 
>> I just want to add:  This is why I really would love for us to have
>> a real RAID3 implemetation.
>> 
>> RAID3 is not commercially viable because windows cannot use non-512
>> byte sectors.
>> 
>> We can.
>> 
>> RAID3 would scream for us.
>
>What about disk arrays that support RAID3?

Would work for me, but most of them are dumbed down when they do RAID3:
they have to hard format the disks to 128 byte sector sizes and similar
madness in order to support 512 bytes sectors on the RAID3 volume.

Some of them use 512 byte sector disks and internal sectorsizes of
N*512 bytes and use their battery-backed cache to pretend to have
512 bytes logical sectorsize.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.


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