SUMMARY: Backups

From: Yves Lepage (yves@CC.McGill.CA)
Date: Thu Sep 29 1994 - 11:19:35 CDT


Sorry for the delay.

Here is what people use for backups (from most used to least used):


Home made scripts


Exabyte 8500 (xl,c, other flavours)
Exabyte 8200

A type a tape drive called Digital Linear Tape (from DEC) seems to
be becoming popular. I am told it is the fastest tape drive I can find
on the market right now and it stores 20GB worth of data on a tape. I do not
know if this is compressed.

Speed: Here is a list of the various combination of software and hardware
       and the speed these people get.

Legato + Exabyte 8500C (jukebox): 10 GB in 7-8 hours with short peeks at 700K/sec
                                  tape drive is local.

Legato + Exabyte 8500 (stacker): compressed data at 500k/sec when no net probs
                                 and fast clients.

Legato + mirrored Exabyte: 10GB in ten hours over ethernet.

Home made scripts + Exabyte 8505: 2GB in 1.5 hour, half of it over ethernet.

Home made scripts + Exabyte 8500: 3GB in 2:18 hours. The tape seems to be local.

Home made C soft. + Exabyte 8500: 370K/sec (average) over network.

Home made perl + Exabyte 8500C : 25GB in 28 hours over network.

EpochBackup + HP optical library + Exabyte jukebox: performance was not a
                                                    criteria. Users can recover
                                                   their own files.

Home made C++ + Exabyte 8200 + Exabyte 8500 : 1.5GB in 2 hours. 63K record size.

Unknown software + Auspex + 2 Exabyte 8500c : 720K/sec. I assume drive is local
                                              to the Auspex.

Legato + 4 Exabyte 8500st : 100GB in 24 hours.
                                              Backup server is on cddi. 90% is

                                              over ethernet. Data is compressed
                                             by the client before it is sent.

EpochBackup + Exabyte 8505xl : 2GB in one hour.

Home made scripts + Exabyte 8500 : 1GB in one hour over ethernet.

Unknown soft. + DAT : 1.5GB in 40 minutes. Drive is local

Home made scripts + Exabyte 8200 : 1.8GB in 2:20 over ethernet.

So it seems that the most limiting factor is the network and then the speed
of the tape. So the solution would be get a faster network and get faster
tapes or write to multiple tapes in parallel.

Legato and EpochBackup do multi-platform backups.

My next step will be to go and see how a Digital Linear Tape (DLT) works, I was
able to find a site here that has one. I'll be evaluating Legato and EpochBackup.
I'll also try an evaluate the possibility of having a backup server on the
backbone (cddi) with tapes connected to it.

I would like to thank the following people for their answers:

Henry Katz <>

Nate Mann AP35-1008 x4774 <>
Jan van Doorn <>
William Charles <>
Richard Davis <> (Don Lewis)
"Kevin A. Noll" <> (Donald McLachlan) (Rick Pluta)
"A. Bryan Curnutt" <curnutt@Stoner.COM>
Pat Max <> (Nishan Sandhar) (Andy Feldt)
Nate Itkin <>
pamela@Legato.COM (Pamela Pledger) (Dan Frenette) (rocky gould)
Daniel Quinlan <danq@spot.Colorado.EDU>
epl@Kodak.COM (Gene Loriot ( (Glenn Satchell - Uniq Professional Services) (Suzanne Bryant)
Robert Velthuizen <>

The original question was:

>Hello all,

>I would like to know what is the maximum backup rate you can achieve and what
>setup you use to do the backups. The case that is of interest to me is doing
>backups of our unix machines. In a not too far future, this could also
>extend to DOS, NT, and Mac machines.

>Here we use home made csh scripts with an exabyte 8200 tapedrive. The backups
>are done via our network which is local ethers and an FDDI/CDDI backbone.

>The rate we are able to achieve is 1.5 gig in 3 hours, which is to me
>a worse than awful performance.

>I'm in the process of trying to solve the backup performance problem
>forever. I would just like to know how did you people solve it?

Yves Lepage

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