If Arkeia is backing up at 180Mb/min then this is equivalent to 3Mb/s, 2-3x faster than tar.
Is Arkeia using compression ??? It is possible, and that may be why it is reporting faster transfer times to tape than tar is. You can also play with the tar blocking factor - it will depend on the network transfer speed. The other thing is, what sort of tape drive are you using, what sort of controller ? What is the maximum rated transfer rate for the tape drive ? Another stupid question - is Arkeia doing a FULL backup or an incremental ? From the look of this, you network is probably not the bottleneck. I would also suggest you take a look at ctar (do a google search). It costs money but you can install a trial version and compare that. Matt At Wednesday, 10-04-02 09:43 (+1000), Gonzalo Servat wrote: >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 > > > > > > -- > > SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/ > > More Info: http://lists.slug.org.au/listinfo/slug -- SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
