- Community Home
- >
- Storage
- >
- Data Protection and Retention
- >
- StoreEver Tape Storage
- >
- Re: Only 12 gig fits on DDS3 with SureStore DAT24
Categories
Company
Local Language
Forums
Discussions
Forums
- Data Protection and Retention
- Entry Storage Systems
- Legacy
- Midrange and Enterprise Storage
- Storage Networking
- HPE Nimble Storage
Discussions
Discussions
Discussions
Forums
Forums
Discussions
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
- BladeSystem Infrastructure and Application Solutions
- Appliance Servers
- Alpha Servers
- BackOffice Products
- Internet Products
- HPE 9000 and HPE e3000 Servers
- Networking
- Netservers
- Secure OS Software for Linux
- Server Management (Insight Manager 7)
- Windows Server 2003
- Operating System - Tru64 Unix
- ProLiant Deployment and Provisioning
- Linux-Based Community / Regional
- Microsoft System Center Integration
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Community
Resources
Forums
Blogs
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО07-09-2002 06:39 AM
тАО07-09-2002 06:39 AM
Only 12 gig fits on DDS3 with SureStore DAT24
Greetings, I have a SureStore DAT24 connected to my server running HP-UX 11.00. I'm using Maxell HS-4/125 DDS 3 tapes. The problem is: I can only fit (about) 12 gig on these tapes. I thought I was able to put 24 gig on these tapes. My tape device is: /dev/rmt/c1t1d0BESTn. Is this a compression problem or a limitation of my setup?
-john
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО07-09-2002 06:43 AM
тАО07-09-2002 06:43 AM
Re: Only 12 gig fits on DDS3 with SureStore DAT24
I have the same problem on one of my servers with oracle backups. The filesystem is about 14Gb filled and the files there are already compressed, so only 12Gb can be used on the tape. Luckily, we have an autochanger and have a script to change the tape once it is filled.
Hope this helps
Chris
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО07-09-2002 06:48 AM
тАО07-09-2002 06:48 AM
Re: Only 12 gig fits on DDS3 with SureStore DAT24
I don't have one of these guys to examine but it is also possible that compression has been disabled by jumper or DIP switch setting.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО07-09-2002 06:48 AM
тАО07-09-2002 06:48 AM
Re: Only 12 gig fits on DDS3 with SureStore DAT24
If a tape is labeled as being able to store 24Gigs, it means that the tape can ONLY hold 12GB's, because they like to screw with our heads and claim that if you "get" compression, then 24GB should be compressable (2:1) down to 12GB's.
It's MARKETING math - fuzzy math - enron math - worldcom accounting - ....
live free or die
harry
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО07-09-2002 06:54 AM
тАО07-09-2002 06:54 AM
Re: Only 12 gig fits on DDS3 with SureStore DAT24
Manoj Srivastava
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО07-09-2002 06:54 AM
тАО07-09-2002 06:54 AM
Re: Only 12 gig fits on DDS3 with SureStore DAT24
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО07-09-2002 07:06 AM
тАО07-09-2002 07:06 AM
Re: Only 12 gig fits on DDS3 with SureStore DAT24
Most(75%) of the data is CAD data(cadence, ads, libra, sonnet). The remainder is split between model files, libraries, scripts, html, and various other user created files.
As far as the jumper setting on the drives, are the set to compression by default? Where can I find information on the jumper settings?
Thanks!
Enron marketing, I like that!
-john
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО07-09-2002 07:10 AM
тАО07-09-2002 07:10 AM
Re: Only 12 gig fits on DDS3 with SureStore DAT24
I was talking this over with a collegue and here is an interesting point. Yes, it is my impression that unless you are using an older drive, compression should be the default. anoter interesting point; We use 0m as our backup device, but when we look at the /dev/rmt directory, it has the same tmestamp as its corresponding BEST device. So it is my impression that in order for you to take full advantage of the available compression of the tape relies on the data.
Hope this helps
Chris
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО07-09-2002 11:15 AM
тАО07-09-2002 11:15 AM
Re: Only 12 gig fits on DDS3 with SureStore DAT24
http://h200004.www2.hp.com/bc/docs/support/SupportManual/lpg28477/lpg28477.pdf
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО07-09-2002 11:46 AM
тАО07-09-2002 11:46 AM
Re: Only 12 gig fits on DDS3 with SureStore DAT24
The compression ratio depends on the type of data, 2-1 is what you can expect with plain text files. With other data I have get anything between 1.2-1 to 5-1 or more. In some cases with already compressed files the ratio can be negative, the data increase instead of decrease.
But, if yor files is not already compressed you should get at least some compression. You can try with another device file, I always use /dev/rmt/0m (or which scsi adress you use).
Another simple test is to use the HP-UX "compress" command on some of the files. As "compress" uses the same algortitm as the drive (LZW) you can expect the same ratio with the drive.