Re: Oracle RAID (RAID7 has no write penalty)
Date: 1995/09/12
Message-ID: <DEtC44.L23_at_world.std.com>#1/1
kmchugh_at_ix.netcom.com (Kevin McHugh) writes:
>In <1995Aug30.100457.28670_at_schbbs.mot.com> RHG054_at_waccvm.corp.mot.com
>(Alvin Lee) writes:
>>
>>I would like to correct a typing error in my message "Re: ORACLE RAID"
>>on Aug25,95 regarding RAID7.
>>
>>" this latest technology give us 100% performance improvement without
>> -------
>> write penalty."
>>
>>Alvin
>>Motorola HK
>Raid-7 or whatever the vendor chooses to call it has been addressed in
>depth in the comp.database.hardware.(scsi??) news group. Just like the
>reading a block from the Oracle buffer cache requires no I/O a write to a
>Raid-7 system that can fit in the buffer of the Raid-7 system will give no
>write penalty. If you saturate the buffer then the systems will suffer
>from the same write penalty as an Ordinary Raid-5 array. Also since
If you saturate the cache buffer, RAID 7 really shows off. You can watch some very impressive RAID 7 write performance in emptying out the cache, another major difference from ordinary RAID. That's what 10+ years of RAID performance R&D is all about.
>these systems require ram and ram still cost $20-50/ megabyte it still
>maybe more cost effective to run Raid 1/0 for disk requirements of
>under 20 gigabytes.
Most all RAID 7 installations are well above 20 GB.
Mike W.
Michael Willett, EE
mwillett_at_storage.com
Storage Computer Corp.
http://www.storage.com/
11 Riverside Street
Nashua, NH 03062
Tel. 603-880-3005
:::I/O-accelerated, very fast disk arrays for all SCSI systems to 1,000 GB::: Received on Tue Sep 12 1995 - 00:00:00 CEST