Hi Russell,
yes they are dlt 7000 drives. and no i'm not getting media errors. but
maybe i need to clean the drives?
i knew i could "format" the media to a higher density. (thx for the
detailed procedure, it does help. tho') but "backwards compatibility" made
it off mark that much?? also is it true every tape will get different
density settings and has a different estimated capacity when marked full?
i'm just curious and want to make sure.
a scratch tape in my dlt-lib is estimated to be ~35G. i think that's
because i defined devclass to be so. as long as adsm think it's full (or
"hits the end of volume") it changes to 28~30G. this makes sense according
to lower density theory. but still notice the %Util field, it's just 64.2%
and it's already marked full. should it be 100% so that all 30G gets used?
i'm a bit confused here 'cause this percentage just seems way tooooo low
to me.
thanks a lot for sparing your time and experience.
yu chen
-- The Lost Patrol. Level 30~36, HP 800, AC -2. The Highway Patrol of
The Random Road, They Keep The Peace, They Eat Donuts. -TRR '97
The Random Road, They Keep The Peace, They Eat Donuts. -TRR '97
On Fri, 30 Oct 1998, Russell Street wrote:
** Tapes get marked "full" when ADSM hits the end of volume. If you are
** getting media errors, this could happen prematurely.
**
**
** They are COMPACT IV tapes? It is a DLT 7000 drive? (DLT 4000 are
** 20GB native, 40GB "typical compression")
**
**
**
** Manually load a tape and look very carefully at the density lights on
** the DLT drive.
**
** DLT tapes can do 35GB, but for backwards compatibility they can do
** lower densities.
**
** The drive decides on the density when the tape is first written to and
** that density is used forever more.
**
** It is possible to "reformat" the media to a higher denisty:
**
** 0. Make sure there is no ADSM data on the tape and the volume has been
** deleted from the library and adsm volume list
** Mark the drive as "offline" in ADSM
** 1. Mount the tape manually in the drive
** 2. Use the "density select" button to choose 35GB
** 3. At the UNIX system
** dd if=/dev/zero of=/dev/rmt/X count=100
** (/dev/rmt/X is the real OS device driver for the drive)
** 4. Unmount the tape
** 5. Mark the drive as online
** 6. Get ADSM to relabel the tape
**
**
** This works because the DLT drive will change the media density IF it
** is writing at the beginning of the tape.
**
** I did this repeatedly when we moved tapes that were used in a DLT 4000
** drive to a DLT7000 library.
**
**
** I am getting > 35GB on my DLT tapes.
**
**
** Hope this is of some help
**
** Russell
**
**
**
**
** > hi adsmers,
** >
** > is there anyone out the experienced the same thing: i just noticed that
** > sometimes adsm changes a filling tape to status full even tho' the tape
** > still got plennnnnnnty of room to put data in. to be more specific, before
** > i did a "move data dlt009" i had:
** >
** >
** >
** > adsm> q vol dlt*
** >
** > Volume Name Storage Device Estimated
%Util Volume
** > Pool Name Class Name Capacity
Status
** > (MB)
** > ------------------------ ----------- ---------- ---------
----- --------
** > DLT001 DLT-LIBRARY DLT-AUTO 27,578.4
58.8 Full
** > ...
** > DLT007 DLT-LIBRARY DLT-AUTO 35,840.0
50.9 Filling
** > DLT008 DLT-LIBRARY DLT-AUTO 35,840.0
6.7 Filling
** > DLT009 DLT-LIBRARY DLT-AUTO 35,840.0
3.8 Filling
** > ...
** >
** >
** >
** > it then moved data off dlt009 to dlt007. but now i have:
** >
** >
** >
** > adsm> q vol dlt*
** >
** > Volume Name Storage Device Estimated
%Util Volume
** > Pool Name Class Name Capacity
Status
** > (MB)
** > ------------------------ ----------- ---------- ---------
----- --------
** > DLT001 DLT-LIBRARY DLT-AUTO 27,578.4
58.8 Full
** > ...
** > DLT007 DLT-LIBRARY DLT-AUTO 30,399.7
64.2 Full
** > DLT008 DLT-LIBRARY DLT-AUTO 35,840.0
7.4 Filling
** > DLT009 DLT-LIBRARY DLT-AUTO 0.0
0.0 Empty
** > ...
** >
** >
** >
** > also, i don't seemed to be able to utilize the whole tape, the estimated
** > full capacity is 35G but it got marked full somewhere around 30G. my
** > devclass of dlt's definition is -format=drive.
** >
** >
** > thanks.
** >
** >
** >
** > yu chen
** >
** >
** >
** >
** > -- The Lost Patrol. Level 30~36, HP 800, AC -2. The Highway Patrol of
** > The Random Road, They Keep The Peace, They Eat Donuts. -TRR '97
**
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