tar to tape drive command


 
Thread Tools Search this Thread
Top Forums UNIX for Advanced & Expert Users tar to tape drive command
# 8  
Old 10-12-2010
You might want to use dd option "bs=65536" or the like so you write more than 512 bytes a record.

tar will embed nulls in his output even to a pipe to compress unless you use cpio or maybe find an option for tar to stifle most or all of the nulls.

The compress is faster than gzip but twice as big, generally, so gzip or gzip -9 or bzip2 is a better choice. Tape is usually slower than CPU even with bzip2. Play around with the compression level options (bzip2 has a bewildering set), and see what is fast enough. Usually, there is not much difference between gzip -7 and gzip -9, but your data and CPU may vary. Oh, look, rzip, 7zip, . . .

---------- Post updated at 04:48 PM ---------- Previous update was at 04:45 PM ----------

rzip(1): large-file compression program - Linux man page
gzip vs. bzip2 vs. rzip (by Jeremy Zawodny)

---------- Post updated at 05:05 PM ---------- Previous update was at 04:48 PM ----------

PS: If you sort the files from find by extension or file type, you get even better compression! The rzip site says it must have a flat file in -- worried about 32 bit VM space, I guess.
Login or Register to Ask a Question

Previous Thread | Next Thread

8 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

tar command to explore multiple layers of tar and tar.gz files

Hi all, I have a tar file and inside that tar file is a folder with additional tar.gz files. What I want to do is look inside the first tar file and then find the second tar file I'm looking for, look inside that tar.gz file to find a certain directory. I'm encountering issues by trying to... (1 Reply)
Discussion started by: bashnewbee
1 Replies

2. AIX

savevg/tar/mksysb of server-A on remote tape drive possible ?

Every 3 months we have to do backups (smitth mksysb/lsmksysb + tar) on at least 30 workstations. We have to carry around 2 external tape drives to connect to them. It is a pain to do because it takes at least 3 days to do (evening/night shift) and users sometimes complain that there desk is not put... (1 Reply)
Discussion started by: Browser_ice
1 Replies

3. Solaris

Tar & Tape drive without media

Hi all, I would like to know what would happen if the tape (media) is not placed on the drive and a tar command is executed to backup on the tape. My problem is that tar command hanged for multiple days instead of throwing the error, Is it valid behaviour? I was unable to test the... (4 Replies)
Discussion started by: jmsathish
4 Replies

4. AIX

Tape Drive

I have tape drive in one Lpar. when i saw that time tape is in defined state. After that i deleted the tape drive using the rmdev -R command. Then fired the cfgmgr -v command. But I am not getting the tape drive. Now the drive is even not in defined state also. It is not shown the tape drive. How... (1 Reply)
Discussion started by: pernasivam
1 Replies

5. Solaris

backup through tar command on remote tape

Hello Everybody I have two servers, name A & B. I need to take a backup of one directory(/girish) on serverA. But my tape drive is in serverB through tar command. But when I run the following command it doesn't take the backup. Could any one correct my command to take a backup tar cvf - ... (0 Replies)
Discussion started by: girish.batra
0 Replies

6. Solaris

tar on remote tape drive

hello guys, am trying to save a file file1 to a remote tape drive using tar and i get a permission denied error as shown below: server1%tar cvf - file1 | rsh server2 dd of=/dev/rmt/1m conv=sync a file1 1883905K permission denied since server2 requires login username and password, i see in... (3 Replies)
Discussion started by: nom
3 Replies

7. UNIX for Advanced & Expert Users

Does tar do crc checking on a tape or tar file?

Trying to answer a question about whether tar table-of-contents is a good tool for verifying tape data. (1 Reply)
Discussion started by: tjlst15
1 Replies

8. Solaris

Command to determine Tape Drive model and make

Hi, We have some IBM LTO tape drives connect over SAN. I have the following questions :- 1) Command that can list the tape drive details like who is manufacturer, model number, make etc etc 2) I would like to know what are the key differences between IBM LTO Generation 1 and Generation... (5 Replies)
Discussion started by: new2prog
5 Replies
Login or Register to Ask a Question
dds2index(1)						      General Commands Manual						      dds2index(1)

NAME
dds2index - tool to create an indexfile for the use of SYNOPSIS
dds2index [options] DESCRIPTION
dds2index creates an index file that is required by the file extraction utility dds2tar(1). It works on tar archives stored on dds tape devices (DAT). Since the file structure of the tape archives is used to extract the files, the archive must be an uncompressed tar ar- chive. But compression by the transparent signal processor of the tape device is allowed. The index created by dds2index is written to stdout by default and should normally be stored on hard disk as indexfile for later use by dds2tar(1). The default tape device to read from is /dev/nst0, which may be overridden with the environment variable TAPE, which in turn may be over- ridden with the -f device option. The device must be a SCSI tape device. OPTIONS
-f devicefile device of the tape archive. Must be a character special file. -t indexfile write the index to indexfile, not to stdout. -z,--compress write the index in (gzip) compressed mode. --help print some screens of online help with examples through a pager and exit immediatley. OPTIONS you didn't really need -b, --block-size Set the maximal blocksize, dds2index can handle. --z, --no-compress Don't filter the archive file through gzip. -v,--verbose verbose mode. Print to stderr what is going on. -h,--hash-mode Print a hash sign '#' to stderr for each MB read from tape. -V,--version Print the version number of dds2index to stderr and exit immediately. EXAMPLES
Example of getting the index from the default tape /dev/nst0 and storing it in file archive.idx: dds2index -v -t archive.idx WARNING
This program can only read records (tar is calling them tape blocks) up to 32 kbytes. A bigger buffer will cause problems with the Linux device driver. ENVIRONMENT
The environment variable TAPE overrides the default tape device /dev/nst0. FILES
/dev/nst0 default tape device file. Must be a character special file. SEE ALSO
dds2tar(1), mt(1), mt-dds(1), tar(1), gzip(1) HISTORY
This program was created as a tool for dds2tar(1). AUTHOR
J"org Weule (weule@cs.uni-duesseldorf.de), Phone +49 211 751409. This software is available at ftp.uni-duesseldorf.de:/pub/unix/apollo 2.4 dds2index(1)