SUMMARY: Solstice Backup

From: Coffindaffer, Virginia (
Date: Wed Nov 27 1996 - 16:43:00 CST

Sun Managers,

Original question:
1. We have a 10 tape jukebox (EXB-210) running with Solstice Backup. How do
we get the 160m tape to save approx. 14 GB of data. I am aware I cannot
actually get 14 GB but I am only now getting 5 GB and the tape says it is
full. There is nothing else on the tape. The device name we are using is
"/dev/rmt/0hbn". What can we do to get more than 5 GB ? Do we set the
capacity or what? We installed as "8mm", "EXB-210" jukebox.
2. When the tape is full, it will not switch to the second tape. Has anyone
else run into this problem ?

1. a. The answer seemed to finally come from Sun after going through 5
engineers. It appears the importance lies in the selection of the type of
device such as "8mm" or "8mm 5GB". This information gets placed in the
label. For example, one of my remote sites selected "8mm 5GB" as the type
and labeled all their tapes using this. Then they found out they could do 14
GB to the EXB-210. So they just changed the device type to "8mm" without
relabeling the tapes. YOU MUST RELABEL if you make this change. Several
engineers just said the capacity came from the "/dev/rmt/xhbn" device
conventions. UNTRUE. If you use "8mm 5GB" as the type, you are only going
to get up to 5 GB no matter what. You should also use the "h" in the device
naming conventions if you want the higher density. (By the way, "c" and "h"
are the same device. This was confirmed by all Sun engineers and also by me
looking at the major and minor device numbers.)
b. All of you that said go to Media -> Devices ->View -> Details to set the
capacity to 14 GB, were incorrect. This value is only used for accounting in
Solstice Backup - such as the % of tape used. This has nothing to do with
the actual storage capacity that the tape actually uses. You could think of
this as reference only for accounting within SB. In other words, if you
place 14 GB in the "default Capacity" and also the "Current Capacity" , the
accounting takes this number to do its accounting of the % of tape used. So
you might be careful about what number used here if you want correct %s. For
example, you would not put "14 GB" here for a 112m tape since this tape will
only give approx. 10 GB total. For a 112m tape, you should put "10 GB" in
this capacity area for accounting. For 14 GB, you need to use 160m tapes.
Of course, if you are using compression, this capacity number will change.
c. Sun also said "Let the device, not the software, do any compression
needed. " Also, if you select both compression in software and also select
compression on the device, you will get double the amount of space used even
if you had never selected compression at all. SO do not do compression in
both places - either do it in the software (slower) or at the hardware level

2. Once a tape is filled, it will not go to the second tape unless "SCSI"
mode is selected on the jukebox LCD panel. This was happening at another
remote site where I could not see how they set up the jukebox - EXB-210.
This site had "sequential" selected and therefore were stopping after the
first tape was filled.

I want to thank all those (over 20) who answered my request

That's all folks.

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