best SCSI config

I am configuring a new db server and have a couple best practice questions.
I read somewhere that a server confgured for SQL server should have its OS
and transation log on a RAID 1 array, and the data file on 1 or more RAID 5
arrays.
1.) Is having a RAID 1 array for the OS and transaction log much better than
having just one RAID 5 array that has the OS, transaction log, and data files?
2.) We are recoding our web application to store pictures and files in the
database rather than on the web servers file system. Our application does a
lot of loading and displaying of photos. How resource intensive is saving a
photo and retreiving it from the database? Will it greatly slow down
non-photo transactions? Would I be wise to put all the photos and files (blob
data) on thier own RAID 5 array?
"Dan" wrote in message
news:C73453B5-76E7-4D6C-8A58-9ED1AC11A87A@.microsoft.com...
:I am configuring a new db server and have a couple best practice questions.
:
: I read somewhere that a server confgured for SQL server should have its OS
: and transation log on a RAID 1 array, and the data file on 1 or more RAID
5
: arrays.
:
: 1.) Is having a RAID 1 array for the OS and transaction log much better
than
: having just one RAID 5 array that has the OS, transaction log, and data
files?
:
: 2.) We are recoding our web application to store pictures and files in the
: database rather than on the web servers file system. Our application does
a
: lot of loading and displaying of photos. How resource intensive is saving
a
: photo and retreiving it from the database? Will it greatly slow down
: non-photo transactions? Would I be wise to put all the photos and files
(blob
: data) on thier own RAID 5 array?
Here is the idea:
RAID 1 (mirroring, duplexing) writes fast, reads normal
RAID 5 (distributed data guarding with parity) writes slow, reads very fast
Log files are written to more often than read from. RAID 1 is a performance
increase over RAID 5.
Data files are read more often than written to. RAID 5 is a performance
increase over RAID 1.
Saving a blob in a database is a waste, IMHO. Save the file on the data
drive and store a link to it in the database.
If your goal is performance, blobs are counter productive.
HTH...
Roland Hall
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