Rich - We use Net Appliance as additional storage on our test system (Compaq
Tru64 / Oracle 8.1.6). I believe the Net Appliance has a dedicated 100-meg
Ethernet connection. It seems to work pretty good, but my experience is that
you can overload the I/O channel. Once, I set a large database up to rebuild
6 or so indexes. Both the indexes and the tables were on the NetApp. On our
regular RAID-5 drives, I estimated that would have taken 4-5 hours. I
started this before I went home. Imagine my surprise the next morning when
none of the indexes had finished. Since then, I have tended to move the
table or index to regular disk, and build one index at a time. Performance
seems to be fine if I do that. Our users haven't complained about
performance, but they haven't subjected it to heavy usage.
From my admittedly meager experience, I would say that if you are
planning to use the Net Appliance for your test system or for some type of
low-activity storage, it would probably be fine. I wouldn't plunge in and
bet my job on the Net Appliance performance on high-activity OLTP tables
until I had a chance to test it thoroughly.
Dennis Williams
DBA
Lifetouch, Inc.
[EMAIL PROTECTED]
-Original Message-
Sent: Thursday, February 14, 2002 4:41 PM
To: Multiple recipients of list ORACLE-L
NetApp Filers use WAFL (Write Anywhere File Layout. WAFL is similar to
other Unix filesystems like FFS in that it's a block-based file system
using inodes to describe files. It uses 4K blocks with no
fragmentation. Each WAFL inode has 16 block pointers that point to data
blocks. Unlike FFS, all the block pointers in a WAFL inode refer to
blocks at the same level. For files smaller than 64K the 16 inode
blocks point to data blocks. Larger files use indirect pointers (inode
blocks point to other inode blocks). Very large files use double
inderect pointers (inode - inode - inode - data). Very small files
use the inode blocks themselves instead of the block pointers.
WAFL stores file system metadata in files (inode file, block-map file,
and inode-map file. Keeping this data in files allows the Filer to
write the data anywhere on the disk (rather than to a superblock like
FFS), which is where the WAFL name comes from. This also allows the
Filer to schedule writes to the same RAID stripe to avoid the 4-1 write
penalty you usually incur when you update a single block in a stripe.
Other nice features from a sysadmin point of view are the fact that the
Filer will automatically increase the size of your filesystem when you
add another disk, and the use of snapshots. Snapshots are really cool
if you haven't seen them before. Basically from the point in time the
snapshot is taken, the filesystem has to write all new data (including
meta-data) to new locations on the disk instead of overwriting the old
data. If WAFL used a superblock like FFS, this wouldn't be possible.
If data is changed, the Filer uses a copy-on-write technique to keep the
old block avialable for any snapshots which reference it.
I've never used a Filer for Oracle applications; I've only used EMC due
to the size availability requirements of the implementations I've
worked on, but I know it's been done by others.
If you poke around at http://www.netapp.com/ you can probably find Dave
Hitz' original white papers on WAFL and the design of the filer
(formerly called FAServer) if this sort of thing interests you.
Rich
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of
Berkmeyer,
Sue
Sent: Thursday, February 14, 2002 10:29 AM
To: Multiple recipients of list ORACLE-L
Subject: DBA-Database Storage using Net Appliance
Hi Everyone,
I am getting pressure from the system guys to use a Net
Appliance
filer for Oracle Applications databases. I currently have the Apps
Release
11.0.3 production database on a Sun E4500, 4G RAM, 6CPU@400Mhz and a
Sun
storage array with a mix of 4 and 9G drives. The production datafiles
are
on Raid 0+1. The production software is mirrored only. Sequential
files
are not raided. I have gone out to the Net Appliance web site and
have
download papers about how to implement Oracle on the filer. I would
like
to
hear from real users rather than the vendor about how this works.
Therefore
I am curious to find out anyone's experience with this storage
technology
-
good or bad. If anyone has any insights about the Net Appliance
technology
itself i.e. raid level, etc. that would be great too. We are also
considering a new Sun direct attached storage solution. Thanks for
your
time.
National Renewable Energy Laboratory
Sue Ellen Berkmeyer
Database Administrator
Phone: 303-275-4143
Fax: 303-275-3603
E-mail: [EMAIL PROTECTED]
--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Berkmeyer, Sue
INET: [EMAIL PROTECTED]
Fat City Network Services-- (858) 538-5051 FAX: (858) 538-5051
San Diego, California
