Hi Matt

I took your advice and tried backing up / on the backup server
(excluding /dev and /proc of course) to tape and tar reported:

Total bytes written: 1427005440 (1.3GB, 1.2MB/s)

It took about 15 minutes to complete this. My fileserver has about 30GB
worth of data. So, it would take approximately 6 hours to complete using
tar. This is just for the fileserver. It's actually taking a lot longer
than 6 hours (since it has to come over through the network) but
anyway... using Arkeia, I can backup the fileserver AND mail server
(which is only an extra 3 or so gigs) in 2 hours and 20 minutes. Arkeia
reports the speed was 180MB/min.

There's something I'm doing wrong here and Arkeia is doing right because
I don't understand how Arkeia can backup ~160 faster than tar.

Any further ideas??



On Tue, 2002-04-09 at 17:56, Matt Hyne wrote:
> 
> Generally, tapes are streaming, so it is possible that if the transfer rate 
> across the network is slow then more tape may be required for the same 
> amount of data.
> 
> Really - you need to determine the bottleneck - can you tar from one 
> machine to the HDD on another and see how long it takes - and then locally 
> tar this data to the tape drive.  That should give you some good ideas of 
> where the performance bottleneck is.
> 
> At Tuesday, 09-04-02 16:42 (+1000), Gonzalo Servat wrote:
> >Hi All
> >
> >I was performing backups across the network using Arkeia until one day
> >the wrong tape was inserted and the whole tape cycle went haywire (as it
> >requires you enter the right tape with the right label or you get a nice
> >email in the morning asking you to insert the right tape - when infact,
> >I DID enter the right tape) and so I got pretty p@#@ed off at Arkeia and
> >decided to switch to using tar (as I can insert any tape and it will
> >write, plus tar is pretty universal accross *nix systems so I can
> >restore on any system)
> >
> >Aaaanyway, the point of my story is... it would normally take ~2.5hours
> >to backup 33GB across the network using Arkeia to tape.
> >With tar, it takes over 8 hours at which point it gives me a nice "no
> >space left on device" message on the screen.
> >
> >I'm not using gzip compression. I've tried this and it doesn't help the
> >speed problem (or capacity problem)
> >
> >The backup unit is an Ecrix VXA-1 using V17 tapes.
> >
> >Any ideas??
> >
> >Thanks in advance!
> >
> >Regards,
> >
> >Gonzalo.
> >
> >
> >--
> >SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/
> >More Info: http://lists.slug.org.au/listinfo/slug
> 
> 
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> SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/
> More Info: http://lists.slug.org.au/listinfo/slug


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