08-09-2010
How to check hardware data compression
Hi,
I'm looking to check the compression ratio applied by hardware to work out how much free space we have on tapes.
mt -f /dev/rmt0 status shows:
Quote:
rmt0 Available 04-08-00-0,0 LVD SCSI 1/2-inch Cartridge Tape Drive
attribute value description user_settable
block_size 0 BLOCK size (0=variable length) True
compress yes Use data COMPRESSION True
density_set_1 66 DENSITY setting #1 True
density_set_2 64 DENSITY setting #2 True
extfm yes Use EXTENDED file marks True
mode yes Use DEVICE BUFFERS during writes True
ret no RETENSION on tape change or reset True
ret_error no RETURN error on tape change or reset True
size_in_mb 200000 Size in Megabytes False
If I add up the output of the
du command and what we backup from the script, it gives me the total space we tape up. So the plan was to find the compression ratio applied and apply that to the size I have noted for each backup. Then simply subtract this from the size of the tape. Although, perhaps there is an easier way to see the free space on a tape?
Cheers,
Rab
Last edited by rab; 11-09-2010 at 10:50 AM..
9 More Discussions You Might Find Interesting
1. Solaris
What command can I run on a Solaris 8 server to check the hardware (ie number of processors, speed of processors, installed memory etc). (4 Replies)
Discussion started by: soliberus
4 Replies
2. SCO
Hi,
We are having an automated system installed on SCO unixware, which runs a End Of Day routine during midnight. Since few days system is hanging at data backup, I have checked the log, system hangs exactly on data compression, any idea or help that why system is hanging only on compression....... (10 Replies)
Discussion started by: tayyabq8
10 Replies
3. Linux
I'm using growisofs to write DVD, e.g.
$ growisofs -Z /dev/dvd -V "Personal Data, `date +"%b, %d %Y"`" -R -J /mnt/d/*
How can I test whether data was written correctly? md5sum or so? (0 Replies)
Discussion started by: Hitori
0 Replies
4. Windows & DOS: Issues & Discussions
Hello,
I have Win NT server running and I want to know how can I get Hardware RAID settings without rebooting the server?
Thanks in advance. (2 Replies)
Discussion started by: sureshcisco
2 Replies
5. UNIX for Advanced & Expert Users
hello,
I'm planning to do inventory of all our servers but this time it's more on physical. Meaning I would like to check all hardware connected to it (external only like storage, power support) including the count Would like to get perhaps its serial nr..(linux and solaris different servers... (2 Replies)
Discussion started by: lhareigh890
2 Replies
6. Solaris
hi all, will command metastats tell whether there is hardware layered raid ?
i intend to do patching and plug out one of the disks in case the one inside encountered issues. (1 Reply)
Discussion started by: Exposure
1 Replies
7. Solaris
Hi
Can i use Solaris LIVE CD to verify that ubuntu has all drivers present for a certain desktop PC?
which Live CD should i use ? there any many varities out there
Before i purchase this expensive PC i want to ensure Solairs has all drivers for it.
Specs are :
Processor Intel Core i7... (1 Reply)
Discussion started by: kashif_islam
1 Replies
8. Shell Programming and Scripting
I have two files
File1.txt
000199458
000199463
000200442
000200831
000200866
000201009
000201050
000201405
000201666
000201682
File2.txt (4 Replies)
Discussion started by: halfafringe
4 Replies
9. HP-UX
Hi,
I have HP-UX version 11.23. Yesterday i saw error on syslog show Ultra SCSI 320 have issue.
This rx3600 connect to EVA. How to check how many LUN connected and the connectivity to EVA?
I suspect on board controller at rx3600 have a problem. The disk on local not show amber light.... (0 Replies)
Discussion started by: mzainal
0 Replies
TM(4) Kernel Interfaces Manual TM(4)
NAME
tm - TM-11/TU-10 magtape interface
DESCRIPTION
The files mt0, ..., mt7 refer to the DEC TU10/TM11 magtape. When closed it can be rewound or not, see below. If it was open for writing,
two end-of-files are written. If the tape is not to be rewound it is positioned with the head between the two tapemarks.
If the 0200 bit is on in the minor device number the tape is not rewound when closed.
A standard tape consists of a series of 512 byte records terminated by an end-of-file. To the extent possible, the system makes it possi-
ble, if inefficient, to treat the tape like any other file. Seeks have their usual meaning and it is possible to read or write a byte at a
time. Writing in very small units is inadvisable, however, because it tends to create monstrous record gaps.
The mt files discussed above are useful when it is desired to access the tape in a way compatible with ordinary files. When foreign tapes
are to be dealt with, and especially when long records are to be read or written, the `raw' interface is appropriate. The associated files
are named rmt0, ..., rmt7. Each read or write call reads or writes the next record on the tape. In the write case the record has the same
length as the buffer given. During a read, the record size is passed back as the number of bytes read, provided it is no greater than the
buffer size; if the record is long, an error is indicated. In raw tape I/O, the buffer must begin on a word boundary and the count must be
even. Seeks are ignored. A zero byte count is returned when a tape mark is read, but another read will fetch the first record of the new
tape file.
FILES
/dev/mt?, /dev/rmt?
SEE ALSO
tp(1)
BUGS
If any non-data error is encountered, it refuses to do anything more until closed. In raw I/O, there should be a way to perform forward
and backward record and file spacing and to write an EOF mark.
TM(4)