Hi Gene I am using DDS-4 DAT tapes 20GM native and 40GB compression So I hope amanda using and amanda, using gzip, can probably put well over 40GB on the tape if your are correct.
Cheers On Fri, 2005-09-30 at 11:33 -0400, Gene Heskett wrote: > On Friday 30 September 2005 08:09, Chuck Amadi Systems Administrator > wrote: > >Hi all and Scott > > > >I am trying a Monthly archive but in order to follow a setup similar to > >Scott I need a tape changer. > > > >I have found a SCSI tape drive spec below it was once used for backups > >prior to moving over to Amanda. > > > >External Seagate DAT subsystem for NT, Windows, NetWare, DDS-3 > >recording format, consists of STD124000N DAT drive (data > >transfer rate 2.2 MB/s, 24 GB capacity with DDS-DC data > >compression), tabletop enclosure, tape, 1 m cable with 50pin > >high density plug, > > > >Thus could this possible be used a a tape changer I have checked the > >Amanda homepage but doesn't mention any devices. > > > >Cheers > > > >Chuck > > It should work just fine, Chuck, as long as thats a large enough > tape. With hardware compression off, it will hold 12GB, and amanda, using > gzip, can probably put well over 24GB on the tape. > > The only caveat is the tape format. Its cheap, and in DDS2's at > least, I had tape trouble after 20-50 passes per tape. They claim a > million passes, but the drives heads are worn out long before that in > my experience. Rotary heads, are like your vcr in design, and the > lifetime is measured in a small number of thousands of hours, like > 3 to 5 for the life of the head. I've had maybe 1% of the problems I > had with DDS2 tapes since I switched to the FILE device on a 200GB drive. > > For rotating heads, the head wear and damage occurs as each head tip > engages the edge of the tape at the start of the track, there is tape > contact and bounce there, but once 'on' the tape, there is a micron > thick air cushion between the tape and the head tip. Its that crash > at the entrance edge of the tape that does the damage. I've looked > at tips that were actually shattered in my many years of keeping > broadcast recorders going. DVC-PRO heads are 1/3rd the size of a dat > head, and they can read and write 100 MB/second these days. But the > electronics in those is 1000x smarter in terms of error correction > too. And the error correction doesn't have to be 100%, as long > as the pixal coming out somewhat resembles what went in, thats good > enough, the eye is a whole lot more forgiving than data storage. > > Todays tape drives are still in the horse and buggy era in comparison. > > >On Fri, 2005-09-30 at 07:39 -0400, Scott R. Burns wrote: > >> Hi Chuck, > >> Sorry I don't have any experience without a changer. You would be > >> best to ask the list about this one. There may be a way to have it > >> pause and prompt for the next tape ? > >> > >> I do know that you can pick up the changer I have on Ebay usually for > >> about $ 100 USD - $ 200 USD with a 30day warrenty. Unfortunately I > >> bought mine brand new in it's day for about $ 3000 USD :-( > >> > >> Scott... > >> > >> Scott R. Burns > >> NETCON Technologies Incorporated > >> Suite 135 - 4474 Blakie Road > >> London, Ontario, Canada > >> N6L 1G7 > >> Voice: +1.519.652.0401 > >> Fax: +1.519.652.9275 > >> Web: www.netcontech.com > >> > >> -----Original Message----- > >> From: Chuck Amadi Systems Administrator [mailto:[EMAIL PROTECTED] > >> Sent: Friday, September 30, 2005 6:23 AM > >> To: Scott R. Burns > >> Subject: RE: My Monthly archive config - issue > >> > >> > >> Hi > >> > >> I have received an error after running amcheck Monthly > >> > >> WARNING: if a tape changer is not available, runtapes must be set to 1 > >> > >> Thus I have not got a tape changer > >> > >> I just want to amflush data that cannot fit on tape 1 to 2,3 or in the > >> future tape 4 to backup potential around 80GB. > >> > >> Cheers > >> > >> Chuck > >> > >> On Thu, 2005-09-29 at 12:23 -0400, Scott R. Burns wrote: > >> > I have a similar setup. I have HW compression turned off on the > >> > drive (HP DAT24X6 changer). > >> > > >> > In my monthly config: > >> > > >> > > >> > dumpcycle 0 weeks > >> > runspercycle 1 > >> > tapecycle 1000 tapes > >> > runtapes 3 > >> > > >> > Also, record is turned off so my normal daily amanda config does not > >> > think the level 0 has been completed after the monthly. > >> > > >> > We never re-use our monthly tapes we send them offsite and leave > >> > them so thats why I have it set to 1000. We use between 2-3 tapes on > >> > a monthly run so runtapes is at 3. > >> > > >> > Scott... > >> > > >> > Scott R. Burns > >> > NETCON Technologies Incorporated > >> > Suite 135 - 4474 Blakie Road > >> > London, Ontario, Canada > >> > N6L 1G7 > >> > Voice: +1.519.652.0401 > >> > Fax: +1.519.652.9275 > >> > Web: www.netcontech.com > >> > > >> > -----Original Message----- > >> > From: [EMAIL PROTECTED] > >> > [mailto:[EMAIL PROTECTED] Behalf Of Chuck Amadi > >> > Systems Administrator > >> > Sent: Thursday, September 29, 2005 12:01 PM > >> > To: Amanda List > >> > Subject: My Monthly archive config - issue > >> > > >> > > >> > Hi again > >> > > >> > Its that time for a monthly archive backup I have currently 80GB > >> > server and using a DAT DDS-4 20GB native 40GB compression I am aware > >> > that I cannot have both hardware compression and software > >> > compression on So Amanda usually behaviour is to have hardware > >> > compression turned off using the mt command. > >> > > >> > Thus my amanda.conf is as follows > >> > > >> > I want a full dump for archiving and this tape will pulled out. > >> > dumpcycle 4 weeks # the number of days in the normal dump > >> > cycle runspercycle 2 # the number of amdump runs in > >> > dumpcycle days # (4 weeks * 5 amdump runs per week -- just weekdays) > >> > tapecycle 12 tapes # the number of tapes in rotation to pull > >> > each monthly tape for archiving. > >> > > >> > runtapes 1 # number of tapes to be used in a normal run. > >> > > >> > Should I increase runtapes to 2 to ensure that I backup at a minimum > >> > 40GB. > >> > Also should I amend dumpcycle to dumpcycle 0 weeks for a full dump > >> > and not incremental. > >> > > >> > Please advice of the best setup to backup for a monthly archive. > >> > > >> > Cheers > >> > > >> > > >> > > >> > > >> > -- > >> > Unix/ Linux Systems Administrator > >> > Chuck Amadi > >> > The Surgical Material Testing Laboratory (SMTL), > >> > Princess of Wales Hospital > >> > Coity Road > >> > Bridgend, > >> > United Kingdom, CF31 1RQ. > >> > Email chuck.smtl.co.uk > >> > Tel: +44 1656 752820 > >> > Fax: +44 1656 752830 > >> > >> -- > >> Unix/ Linux Systems Administrator > >> Chuck Amadi > >> The Surgical Material Testing Laboratory (SMTL), > >> Princess of Wales Hospital > >> Coity Road > >> Bridgend, > >> United Kingdom, CF31 1RQ. > >> Email chuck.smtl.co.uk > >> Tel: +44 1656 752820 > >> Fax: +44 1656 752830 > -- Unix/ Linux Systems Administrator Chuck Amadi The Surgical Material Testing Laboratory (SMTL), Princess of Wales Hospital Coity Road Bridgend, United Kingdom, CF31 1RQ. Email chuck.smtl.co.uk Tel: +44 1656 752820 Fax: +44 1656 752830
