Hi, There is a secret (as always) configuration file that disable the drive compression from netbackup. Someone send it to me before some years, but I cannot find it.
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Justin Piszcz Sent: Wednesday, January 27, 2010 4:07 PM To: Whelan, Patrick Cc: [email protected] Subject: Re: [Veritas-bu] Question with Tape Compression: Is it possible to turnit off? Hi, That is in Solaris, correct? For Linux, per the manpage: Files /dev/st* : the auto-rewind SCSI tape devices /dev/nst* : the non-rewind SCSI tape devices Do not see a tape drive device that disables compression in Linux. It does talk about it here: http://wiki.zmanda.com/index.php/Hardware_compression From: /etc/stinit.def manufacturer=XXXXX model = "YYYYY" { mode1 compression=1 mode2 compression=0 } The problem though is NBU will turn it on again after the first initialization. For Solaris: Set ST_MODE_SEL_COMP in st.conf for your device and then use the correct tape device variant (do not use "c" and "u" device) Even so, I wonder if NBU tries to re-enable it on the drive in Solaris. Justin. On Wed, 27 Jan 2010, Whelan, Patrick wrote: > Could you not specify /dev/rmt/xxubn instead of /dev/rmt/cbn in the > drive configuration? This would stop compression to the drive always. Of > course if you are unfortunate enough to be running windows, then you may > be out of luck. > > > Patrick Whelan > NetBackup Specialist > Wholesale Markets and Treasury & Trading > Lloyds Banking Group > Desk: +44 (0) 207 158 6123 > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Justin > Piszcz > Sent: 27 January 2010 13:41 > To: [email protected] > Subject: [Veritas-bu] Question with Tape Compression: Is it possible to > turnit off? > > Hello, > > If you backup highly compressed files, it carries with it anywhere > between 1-5% overhead overall. > > Example: 400GB LTO-3 Tape > Example: ~367GB and the tape is FULL: > > LTO-3 TAPE: > XXXXXX 9 44 12/10/2009 04:46 12/10/2009 10:13 hcart3 > 367050755 0 > MPX INFINITY N/A FULL > > You can disable compression on a tape drive using the mt command, > however, NetBackup will re-enable it: > >> From Symantec: > There is no direct way to turn off hardware compression from NetBackup. > If you use mt command to set the compression, it is effective only for > the currently loaded tape. Once the tape is unloaded the default > compression setting takes into effect. You will have to contact the > hardware vendor to disable the tape compression > > It is also not possible to disable tape compression on the drives via > ACSLS (for those who run ACSLS0 with Sun robots. > > And the pre and post backup scripts on the client would not help here. > Basically, there is no 'easy' way to make this work correctly. > > The only thing I could think of is if the client called a pre_backup > script and told the media server, "hey, turn compression off" this might > work BUT it would only work if MPX=1 or there was no multiplexing as > there would be other jobs running to that tape drive. In addition, if > you do have a lot of tape drives on a media server, ugh, you see my > point. > > Any other thoughts on this one? > > Justin. > > _______________________________________________ > Veritas-bu maillist - [email protected] > http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu > > > This e-mail is private and confidential and may contain privileged material. If you have received this e-mail in error, please notify the sender and delete it immediately. You must not copy, distribute, disclose or use any of the information in it or any attachments. > > Lloyds Banking Group plc. Registered Office: The Mound, Edinburgh EH1 1YZ. Registered in Scotland, number 95000. Telephone: 0131 225 4555. > > Lloyds TSB Bank plc. Registered Office: 25 Gresham Street, London EC2V 7HN. Registered in England and Wales, number 2065. Telephone: 020 7626 1500. > > Lloyds TSB Scotland plc. Registered Office: Henry Duncan House, 120 George Street, Edinburgh EH2 4LH. Registered in Scotland, number 95237. Telephone: 0131 225 4555. > > Cheltenham & Gloucester plc. Registered Office: Barnett Way, Gloucester GL4 3RL. Registered in England and Wales, number 2299428. Telephone: 01452 372372. > > Cheltenham & Gloucester Savings is a division of Lloyds TSB Bank plc. > Lloyds TSB Bank plc, Lloyds TSB Scotland plc and Cheltenham & Gloucester plc are authorised and regulated by the Financial Services Authority. > > Telephone calls may be monitored or recorded. > > > ______________________________________________________________________ > This email has been scanned by the MessageLabs Email Security System. > For more information please visit http://www.messagelabs.com/email > ______________________________________________________________________ > _______________________________________________ > Veritas-bu maillist - [email protected] > http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu > _______________________________________________ Veritas-bu maillist - [email protected] http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu _______________________________________________ Veritas-bu maillist - [email protected] http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
