SUMMARY: Backup for large DB

Date: Fri Jul 14 1995 - 18:46:06 CDT

Thanks to all who sent suggestions: (Henry Katz) (Jochen Bern) (Kohler R. P.) (Mike Blandford) (Rahul Roy) (Michael Baumann) (Bruce L. Harrell) (Marc Gibian) (Phillip Millman) (Mayank Gupta)

Here are the high spots: (Henry Katz) wrote:

Yes, I was backing up 200+ Gb nightly on 1700+ nodes for a client
using Legato Networker software. Has its bugs but does a great job.
Need some help?

------------------------------------------------------------------- (Jochen Bern) wrote:

SUN's Backup Copilot (or whatever it's Name du Jour is).


We use Networker and 4MM DAT stacker (4 tapes) to backup ORACLE
databice on Solaris 2.*.

With rotating hot backups, you can pretty well use the tape drive
24x7, and with tape drive compression turned on, you'll see
5-10GB per tape.

Unattended in this case means changing tapes every few days.

From: (Kohler R. P.)

I like the EXB-210's for our 20GB databases.. we have 6 of them.

You may want to look at the EXB-440's. 4 drives, 40 slots, each tape
hold 7GB uncompressed, 14GB compressed, drives are 8505XL which have
hardware compression built on.

From: (Mike Blandford)

I use epoch's backup software with an hp optical jukebox
and an exabyte 8mm jukebox. The hp jukebox does file staging
and the exabyte does the real backup. We are currently
storing ~1 terabyte of data. This all runs unattended. It has
worked very well for us and find that even our users
can recover their own stuff without bugging me.


From: (Michael Baumann)
On Tue, 4 Jul 1995 wrote:

Well.. An inexpensive solution might be the following:
Get Backup Copilot (4.1.x) or Online:Backup(Sol 2.x) for about $600
and get a Exabyte 10H stacker with a 8505XL onboard. this will
give you a minimum of 70GB backup (using long tapes) or 50GB
using standard tapes.. since the XL does compression, you could effectively
double that. Copilot allows you to lock the partition for the duration
of the backup. We have been able to sustain > 700KB/sec on a SS1000E.
Something to think about.

From: (Bruce L. Harrell)

Call Legato and ask about NetWorker. The best backup software product
period. For any platform includeing novell and sco. Phone
number is (415) 812-6000 or support at (415) 812-6100.

From: (Marc Gibian)

I see no reason to consider an unattended backup unreasonable. The
only major factor(s) that you need to address that I can think of are:

1. You must have unattended media capacity large enough for your full
disk capacity. Estimate based on a full backup to cover those periodic
fulls in a worst case scenario where your disks are full. Since I know
of no media where a single unit can hold 40gb, you need either enough
drives to hold enough media to hold your full disk capacity, or you
need a jukebox that can perform unattended media changes.

2. You must have software that can handle media changes, either
multiple drives or using a jukebox. This means using something like
Legato's Networker or competing products. Plain old dump isn't going
to cut it. By the way, you might need to go this route anyway to get
quality database backups depending on the database software you are

3. Bandwidth. If you are not connecting the media drives to the
machine holding the database, you need to insure enough network
bandwidth is available to allow transfer of the full disk capacity
within the unattended night timeframe.

By the way, you can also look at this as a way to do rigorous backups
of your full heterogeneous network as the tools and media demands are
pretty much the same. The only difference is that you need more
network bandwidth that you would if you only address the database.

From: (Phillip Millman)

THe answer is YES but it will depend on which RDBMS he uses. At 40GB
it is out of the realm of a OLTP. You may big trouble in 4GL's
like Oracle or Sybase. You might be better off with a DB
Warehouse (like RedBrick.) RedBrick can do unattended backups with
sertian types of Hardware.

Try Calling Jim Cumella of Red Brick (203) 831-9246 if you are

From: (Mayank Gupta)

You would want to parallelize the backup using several tape drives(and maybe
some disk) simultaneously. The above assumes the software will allow it. If
you have room on your scsi chains then several stacker devices along with
disk for a temporary storage area would be ideal. Your database would backup
to disk(which is fast) and then write out to the tape devices(which would be
written to in parallel).

mayank gupta
mercantile software systems


some software solutions

SQL backtrack(sybase)

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