SUMMARY: Backup device choices

From: Sam Don (
Date: Fri Feb 25 2000 - 17:00:58 CST

My original post:

>Currently we have an Auspex server 1.9.2M1Z6/SunOS 4.1.4 (AUSPEX1) with
>about 200 gigs of data. (This is to be upgraded to 750 gigs capacity end of
>this quarter on a new Auspex server and Solaris 2.6). This server is on the
>3.2 gig backbone and also 100baseT.
>The Netbackup server (version 3.2) is on an Ultra10, 100baseT network.
>I would really appreciate any recommendations of a cost-effective backup
>device, or how to do the research. Real world advice welcome.


"Patrick Boyle" <>

>Give some serious consideration to Sony AIT technology.
>The drives are cheap. The data xfer is fast,
>Tape Capacity:
>AIT 2 130 GB compressed (at 2:1 Compression, but we are seeing
>Much higher compression, sony advertises 2.6:1 compression)
>DLT-7000 is at 70 GB with 2:1 compression.
>Transfer rate:
>AIT-2 15.6 MB / compressed.
>DLT7000 10 MB/compressed
>Load time:
>AIT 27 seconds with Mic ( read about the mic chip)
>DLT7K 60 Seconds (ya, right, ever measure this yourself? Pozak was nice
>8MM tape cartridge size is about 1/3 smaller than DLT.
>DLT is at the End of it's life cycle as I see it. AIT is in it's >second
>phase. Drive costs are set in stone, (or something like that) >and you are
>suppose to be able to get the first generation of drives >for the same
>price as the next. I.E. $5000.
>We saved $40K on drives by going with AIT rather than DLT, in 8 >Drives.
>(rough number, off the top of my head)

"BAHNMILLER,BRYAN (A-ColSprings,ex1)" <>

> At my last job we were backing up an Auspex over the network that had
>about 400GB of disk. We put 4 100BTx NICs in the Auspex. 2 were
>etherchanneled for the operational network, the other 2 were used as 2
>separate interfaces to the backup networks.
> We backed up to an E3000 that had 2 100BTx interfaces on each of those
>backup networks also. We then NFS mounted the Auspex partitions over the 2
>different backup networks. So we did NFS backups of the Auspex.
> The other way to do it is to use the FastBackup option on the Auspex.
>This involves paying a heavy duty license fee (> $10K I believe) to Auspex,
>paying for a Netbackup server license to Veritas, and dedicating however
>many tape drives to a direct SCSI connect to the Auspex.
> Your basic limitations are: you essentially need 1 - 100BTx interface to
>keep a DLT7000/8000 full to do a network backup; you need a switched
>network backbone to do this also; your backup server must have enough
>network bandwidth to keep however many drives it has attached, full; you
>need to
>have enough server backplane bandwidth to handle the backups (I would be
>slightly skeptical of using an Ultra10.)
> You can use a NetBackup client on the Auspex, but then you are running
>backups through the HP, which will limit you to about 3MB/s max throughput.
> The FastBackup option uses a direct connect to the SP's which can give up
>to 10MB/s for each connection - at a cost. The NFS option can be the
>cheapest, if you have a heavy duty enough server and a good network
>backbone. I am assuming using DLT7000/8000's because they have pretty good
>throughput and capacity - about 6-9MB/s and 50+GB compressed. You can use
>the new 9840 drives (IBM style). They have up to 12MB/s throughput, but
>with about 30GB capacity (uncompressed.) They also cost about $30K each!
> Also, 5MB/s (worst case throughput to DLT7000 tape drives) is equivalent
>to 17.6GB/hr. How many tape drives will you need to backup a 200 GB server
>- or a 750 GB server? What's your backup window? Design it backwards from
>that. IMHO.

"Cheng, Bruce" <

off the top of my head, you'll need a 20 tape DLT7000 to perform one
full backup without human intervention.

A 30 tape library would do fine.

You can start with one tape drive in the library and expand to higher
number if you need a smaller backup window.

If you do not need to backup all data all at once (for a full backup),
you can settle with a 8 tape DLT tape library (ATL and SUN has one, they are
all the same)

Split the backup of the auspex into two different schedule. To complete a
full backup, you can have half done in one day and half done in another.

Optimal choice: 30 tape DLT tape library with 2 x 7000 drives, barcode
reader, two scsi path.

Are you going to attach the library directly to the Auspex? Or backup via a
backup server and dedicated backup network?

Mike DeMarco <>

I found that trying to run backups off the host processor on a Auspex
box would bog down that processor. So I decided to use the network
processors and automounter to mount the Auspex drives to the backup
server through a private ATM (OC12/622) network to the backup server.
Flawlessly working for over 2 years now using netbackup.
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