RE: TBTAPE Level 0 Multiple Tape Archive
A customer on ONLINE 5.10.UD4/AIX 4.3.3 had outgrown single-tape tbtape level-0 archives; while waiting for bigger tapes, the poster asked whether AIX offers a compressing tape device or an Informix compression setting so backups fit on one tape (and still restore). Replies: there's no special compressed device, but drives can have hardware compression enabled by default (roughly 45-55% on text, 10-20% on binary), checkable/settable with mt/tape commands; and /dev/rmt0.4 uses density setting #2, with a posted table of the rmt*.0-7 rewind/retension/density combinations. No confirmation of whether it solved the problem is recorded.
Auto-generated by DrWatson from the posts below — may be imperfect; read the full thread.
While I am waiting for this customer to order and receive some larger capacity tapes -- and even this is only a temporary solution to them staying on one tape ... It has been a long time since I have used such a creature but isn't there an equivalent to /dev/rmt0 that signals to perform compression at the UNIX level? For AIX 4.3.3? Does it play well with Informix's tbtape restores? I am wondering if there was an environment parameter available that would "ENABLE_COMPRESSION" that would allow the backup to become compressed as it is written to tape and be recognized if (when) it comes time to perform a restore? Any ideas? Thanks in advance and have a good weekend. Clifton -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Andrew Lennard Sent: Thursday, December 14, 2006 4:27 AM To: ids@iiug.org Subject: RE: TBTAPE Level 0 Multiple Tape Archive [7998] It wouldn't help with your efforts to get an upgrade, but is there any chance of fitting a larger capacity tape drive? >From: "Clifton Bean" <cbean@ctm.com> >Reply-To: ids@iiug.org >To: ids@iiug.org >Subject: TBTAPE Level 0 Multiple Tape Archive [7985] >Date: Wed, 13 Dec 2006 12:27:32 -0500 (EST) > >ONLINE 5.10.UD4 > >AIX 4.3.3 > >Please believe me when I say I have been trying to get an upgrade approved >for this customer. Now, I believe they may be running into an issue that >may force the issue of an upgrade to the forefront: > >Their tbtape backup, until recently, was using only one tape as part of >their level 0 archive. No issues there. I have been able to restore their >backups without any resulting issues. > >Now the problem: the customer has finally accumulated enough data in their >instance to require two tapes. When the first tape fills, the operator gets >the message that the first tape has filled and they need to mount another >tape, the activity on the instance comes to a stop until the second tape >has >completed the backup process or until the operator cancels the backup, at >which point normal database activity continues as if nothing happened. I do >not know if the Operations staff is watching the backup and is switching >the >tapes ASAP after the first fills and rewinds or if some time passes. > >Does this remind anyone of a bug on this or earlier 5.10 engines? > >As a workaround, I have asked the customer's operations staff to try to >perform the archives earlier in the morning when the users would be less >affected or to perform a level 1 archive which will allow them to stay >within one tape for now. > >I am also considering performing the backup to disk that can be written to >tape later; however, I am unsure if this would run into the same issue as >the operator needing to change the tape or not. > >Take care. > >Clifton M. Bean >Informix DBA / AIX System Admin >Currency Technics & Metrics >1431 Greenway Drive #700 >Irving, Texas 75038 > >Main (972) 812-1411 x244 > >Toll Free (800) 834-8807 x244 > >Fax (469) 417-0665 > > >*************************************************************************** **** > Forum Note: Use "Reply" to post a response in the discussion forum. > _________________________________________________________________ It's Hotmail's 10th Birthday! Come and play Pass the Parcel http://www.msnpasstheparcel.com **************************************************************************** *** Forum Note: Use "Reply" to post a response in the discussion forum.
Cliff, No 'compressed' devices on AIX that I'm aware of, but most of the drives have a way to turn compression on as the default. Be aware that the compressions algorithms on the drives are optimized for text and are mostly doing run length compression. They get about 45-55% compression on pure text but closer to 10-20% on binary data. Any AIX SA'a out there that know of an OS level util to set the compression on these drives? Art S. Kagel ----- Original Message ----- From: Clifton Bean <ids@iiug.org> At: 1/12 10:14:02 While I am waiting for this customer to order and receive some larger capacity tapes -- and even this is only a temporary solution to them staying on one tape ... It has been a long time since I have used such a creature but isn't there an equivalent to /dev/rmt0 that signals to perform compression at the UNIX level? For AIX 4.3.3? Does it play well with Informix's tbtape restores? I am wondering if there was an environment parameter available that would "ENABLE_COMPRESSION" that would allow the backup to become compressed as it is written to tape and be recognized if (when) it comes time to perform a restore? Any ideas? Thanks in advance and have a good weekend. Clifton -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Andrew Lennard Sent: Thursday, December 14, 2006 4:27 AM To: ids@iiug.org Subject: RE: TBTAPE Level 0 Multiple Tape Archive [7998] It wouldn't help with your efforts to get an upgrade, but is there any chance of fitting a larger capacity tape drive? >From: "Clifton Bean" <cbean@ctm.com> >Reply-To: ids@iiug.org >To: ids@iiug.org >Subject: TBTAPE Level 0 Multiple Tape Archive [7985] >Date: Wed, 13 Dec 2006 12:27:32 -0500 (EST) > >ONLINE 5.10.UD4 > >AIX 4.3.3 > >Please believe me when I say I have been trying to get an upgrade approved >for this customer. Now, I believe they may be running into an issue that >may force the issue of an upgrade to the forefront: > >Their tbtape backup, until recently, was using only one tape as part of >their level 0 archive. No issues there. I have been able to restore their >backups without any resulting issues. > >Now the problem: the customer has finally accumulated enough data in their >instance to require two tapes. When the first tape fills, the operator gets >the message that the first tape has filled and they need to mount another >tape, the activity on the instance comes to a stop until the second tape >has >completed the backup process or until the operator cancels the backup, at >which point normal database activity continues as if nothing happened. I do >not know if the Operations staff is watching the backup and is switching >the >tapes ASAP after the first fills and rewinds or if some time passes. > >Does this remind anyone of a bug on this or earlier 5.10 engines? > >As a workaround, I have asked the customer's operations staff to try to >perform the archives earlier in the morning when the users would be less >affected or to perform a level 1 archive which will allow them to stay >within one tape for now. > >I am also considering performing the backup to disk that can be written to >tape later; however, I am unsure if this would run into the same issue as >the operator needing to change the tape or not. > >Take care. > >Clifton M. Bean >Informix DBA / AIX System Admin >Currency Technics & Metrics >1431 Greenway Drive #700 >Irving, Texas 75038 > >Main (972) 812-1411 x244 > >Toll Free (800) 834-8807 x244 > >Fax (469) 417-0665 > > >*************************************************************************** **** > Forum Note: Use "Reply" to post a response in the discussion forum. > _________________________________________________________________ It's Hotmail's 10th Birthday! Come and play Pass the Parcel http://www.msnpasstheparcel.com **************************************************************************** *** Forum Note: Use "Reply" to post a response in the discussion forum. ******************************************************************************* Forum Note: Use "Reply" to post a response in the discussion forum.
On 12/01/07, Clifton Bean <cbean@ctm.com> wrote: > > While I am waiting for this customer to order and receive some larger > capacity tapes -- and even this is only a temporary solution to them staying > on one tape ... > > It has been a long time since I have used such a creature but isn't there an > equivalent to /dev/rmt0 that signals to perform compression at the UNIX > level? For AIX 4.3.3? Does it play well with Informix's tbtape restores? > > I am wondering if there was an environment parameter available that would > "ENABLE_COMPRESSION" that would allow the backup to become compressed as it > is written to tape and be recognized if (when) it comes time to perform a > restore? > > Any ideas? > > Thanks in advance and have a good weekend. > Clifton > > -----Original Message----- > From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Andrew > Lennard > Sent: Thursday, December 14, 2006 4:27 AM > To: ids@iiug.org > Subject: RE: TBTAPE Level 0 Multiple Tape Archive [7998] > > It wouldn't help with your efforts to get an upgrade, but is there any > chance of fitting a larger capacity tape drive? > > >From: "Clifton Bean" <cbean@ctm.com> > >Reply-To: ids@iiug.org > >To: ids@iiug.org > >Subject: TBTAPE Level 0 Multiple Tape Archive [7985] > >Date: Wed, 13 Dec 2006 12:27:32 -0500 (EST) > > > >ONLINE 5.10.UD4 > > > >AIX 4.3.3 > > > >Please believe me when I say I have been trying to get an upgrade approved > >for this customer. Now, I believe they may be running into an issue that > >may force the issue of an upgrade to the forefront: > > > >Their tbtape backup, until recently, was using only one tape as part of > >their level 0 archive. No issues there. I have been able to restore their > >backups without any resulting issues. > > > >Now the problem: the customer has finally accumulated enough data in their > >instance to require two tapes. When the first tape fills, the operator gets > > >the message that the first tape has filled and they need to mount another > >tape, the activity on the instance comes to a stop until the second tape > >has > >completed the backup process or until the operator cancels the backup, at > >which point normal database activity continues as if nothing happened. I do > > >not know if the Operations staff is watching the backup and is switching > >the > >tapes ASAP after the first fills and rewinds or if some time passes. > > > >Does this remind anyone of a bug on this or earlier 5.10 engines? > > > >As a workaround, I have asked the customer's operations staff to try to > >perform the archives earlier in the morning when the users would be less > >affected or to perform a level 1 archive which will allow them to stay > >within one tape for now. > > > >I am also considering performing the backup to disk that can be written to > >tape later; however, I am unsure if this would run into the same issue as > >the operator needing to change the tape or not. > > > >Take care. > > > >Clifton M. Bean > >Informix DBA / AIX System Admin > >Currency Technics & Metrics > >1431 Greenway Drive #700 > >Irving, Texas 75038 > > > >Main (972) 812-1411 x244 > > > >Toll Free (800) 834-8807 x244 > > > >Fax (469) 417-0665 > > Clifton Try /dev/rmt0.4 should use a higher density but may be less reliable depending on the tape quality. TEST Keith
You can also run an 'mt' or 'tape' command against the drive to make sure compression is turned on. Man pages will give you the syntax for your system but a typical command in Linux is: mt -f /dev/st0 compression Bob Roussey Unix / Informix Administration Spirit Airlines Robert.Roussey@SpiritAir.com -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Keith Simmons Sent: Friday, January 12, 2007 10:27 AM To: ids@iiug.org Subject: Re: TBTAPE Level 0 Multiple Tape Archive [8181] On 12/01/07, Clifton Bean <cbean@ctm.com> wrote: > > While I am waiting for this customer to order and receive some larger > capacity tapes -- and even this is only a temporary solution to them staying > on one tape ... > > It has been a long time since I have used such a creature but isn't there an > equivalent to /dev/rmt0 that signals to perform compression at the UNIX > level? For AIX 4.3.3? Does it play well with Informix's tbtape restores? > > I am wondering if there was an environment parameter available that would > "ENABLE_COMPRESSION" that would allow the backup to become compressed as it > is written to tape and be recognized if (when) it comes time to perform a > restore? > > Any ideas? > > Thanks in advance and have a good weekend. > Clifton > > -----Original Message----- > From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Andrew > Lennard > Sent: Thursday, December 14, 2006 4:27 AM > To: ids@iiug.org > Subject: RE: TBTAPE Level 0 Multiple Tape Archive [7998] > > It wouldn't help with your efforts to get an upgrade, but is there any > chance of fitting a larger capacity tape drive? > > >From: "Clifton Bean" <cbean@ctm.com> > >Reply-To: ids@iiug.org > >To: ids@iiug.org > >Subject: TBTAPE Level 0 Multiple Tape Archive [7985] > >Date: Wed, 13 Dec 2006 12:27:32 -0500 (EST) > > > >ONLINE 5.10.UD4 > > > >AIX 4.3.3 > > > >Please believe me when I say I have been trying to get an upgrade approved > >for this customer. Now, I believe they may be running into an issue that > >may force the issue of an upgrade to the forefront: > > > >Their tbtape backup, until recently, was using only one tape as part of > >their level 0 archive. No issues there. I have been able to restore their > >backups without any resulting issues. > > > >Now the problem: the customer has finally accumulated enough data in their > >instance to require two tapes. When the first tape fills, the operator gets > > >the message that the first tape has filled and they need to mount another > >tape, the activity on the instance comes to a stop until the second tape > >has > >completed the backup process or until the operator cancels the backup, at > >which point normal database activity continues as if nothing happened. I do > > >not know if the Operations staff is watching the backup and is switching > >the > >tapes ASAP after the first fills and rewinds or if some time passes. > > > >Does this remind anyone of a bug on this or earlier 5.10 engines? > > > >As a workaround, I have asked the customer's operations staff to try to > >perform the archives earlier in the morning when the users would be less > >affected or to perform a level 1 archive which will allow them to stay > >within one tape for now. > > > >I am also considering performing the backup to disk that can be written to > >tape later; however, I am unsure if this would run into the same issue as > >the operator needing to change the tape or not. > > > >Take care. > > > >Clifton M. Bean > >Informix DBA / AIX System Admin > >Currency Technics & Metrics > >1431 Greenway Drive #700 > >Irving, Texas 75038 > > > >Main (972) 812-1411 x244 > > > >Toll Free (800) 834-8807 x244 > > > >Fax (469) 417-0665 > > Clifton Try /dev/rmt0.4 should use a higher density but may be less reliable depending on the tape quality. TEST Keith ************************************************************************ ******* Forum Note: Use "Reply" to post a response in the discussion forum.
Keith: The customer has been quite good about not reusing their tapes to the point of destruction. The following devices are listed: >ls -l rmt0* crw-rw-rw- 1 root system 22, 0 Jan 12 07:38 rmt0 crw-rw-rw- 1 root system 22, 1 Dec 04 11:52 rmt0.1 crw-rw-rw- 1 root system 22, 2 Apr 24 2003 rmt0.2 crw-rw-rw- 1 root system 22, 3 Apr 24 2003 rmt0.3 crw-rw-rw- 1 root system 22, 4 Apr 24 2003 rmt0.4 crw-rw-rw- 1 root system 22, 5 Apr 24 2003 rmt0.5 crw-rw-rw- 1 root system 22, 6 Apr 24 2003 rmt0.6 crw-rw-rw- 1 root system 22, 7 Apr 24 2003 rmt0.7 You stated to (possibly) use rmt0.4 to enable more density on the tape. Do you know what the other rmt0 devices enable/disable/allow? Take care. Clifton -----Original Message----- From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Keith Simmons Sent: Friday, January 12, 2007 9:27 AM To: ids@iiug.org Subject: Re: TBTAPE Level 0 Multiple Tape Archive [8181] On 12/01/07, Clifton Bean <cbean@ctm.com> wrote: > > While I am waiting for this customer to order and receive some larger > capacity tapes -- and even this is only a temporary solution to them staying > on one tape ... > > It has been a long time since I have used such a creature but isn't there an > equivalent to /dev/rmt0 that signals to perform compression at the UNIX > level? For AIX 4.3.3? Does it play well with Informix's tbtape restores? > > I am wondering if there was an environment parameter available that would > "ENABLE_COMPRESSION" that would allow the backup to become compressed as it > is written to tape and be recognized if (when) it comes time to perform a > restore? > > Any ideas? > > Thanks in advance and have a good weekend. > Clifton > > -----Original Message----- > From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Andrew > Lennard > Sent: Thursday, December 14, 2006 4:27 AM > To: ids@iiug.org > Subject: RE: TBTAPE Level 0 Multiple Tape Archive [7998] > > It wouldn't help with your efforts to get an upgrade, but is there any > chance of fitting a larger capacity tape drive? > > >From: "Clifton Bean" <cbean@ctm.com> > >Reply-To: ids@iiug.org > >To: ids@iiug.org > >Subject: TBTAPE Level 0 Multiple Tape Archive [7985] > >Date: Wed, 13 Dec 2006 12:27:32 -0500 (EST) > > > >ONLINE 5.10.UD4 > > > >AIX 4.3.3 > > > >Please believe me when I say I have been trying to get an upgrade approved > >for this customer. Now, I believe they may be running into an issue that > >may force the issue of an upgrade to the forefront: > > > >Their tbtape backup, until recently, was using only one tape as part of > >their level 0 archive. No issues there. I have been able to restore their > >backups without any resulting issues. > > > >Now the problem: the customer has finally accumulated enough data in their > >instance to require two tapes. When the first tape fills, the operator gets > > >the message that the first tape has filled and they need to mount another > >tape, the activity on the instance comes to a stop until the second tape > >has > >completed the backup process or until the operator cancels the backup, at > >which point normal database activity continues as if nothing happened. I do > > >not know if the Operations staff is watching the backup and is switching > >the > >tapes ASAP after the first fills and rewinds or if some time passes. > > > >Does this remind anyone of a bug on this or earlier 5.10 engines? > > > >As a workaround, I have asked the customer's operations staff to try to > >perform the archives earlier in the morning when the users would be less > >affected or to perform a level 1 archive which will allow them to stay > >within one tape for now. > > > >I am also considering performing the backup to disk that can be written to > >tape later; however, I am unsure if this would run into the same issue as > >the operator needing to change the tape or not. > > > >Take care. > > > >Clifton M. Bean > >Informix DBA / AIX System Admin > >Currency Technics & Metrics > >1431 Greenway Drive #700 > >Irving, Texas 75038 > > > >Main (972) 812-1411 x244 > > > >Toll Free (800) 834-8807 x244 > > > >Fax (469) 417-0665 > > Clifton Try /dev/rmt0.4 should use a higher density but may be less reliable depending on the tape quality. TEST Keith **************************************************************************** *** Forum Note: Use "Reply" to post a response in the discussion forum.
On 12/01/07, Clifton Bean <cbean@ctm.com> wrote: > > Keith: > > The customer has been quite good about not reusing their tapes to the point > of destruction. > > The following devices are listed: > >ls -l rmt0* > crw-rw-rw- 1 root system 22, 0 Jan 12 07:38 rmt0 > crw-rw-rw- 1 root system 22, 1 Dec 04 11:52 rmt0.1 > crw-rw-rw- 1 root system 22, 2 Apr 24 2003 rmt0.2 > crw-rw-rw- 1 root system 22, 3 Apr 24 2003 rmt0.3 > crw-rw-rw- 1 root system 22, 4 Apr 24 2003 rmt0.4 > crw-rw-rw- 1 root system 22, 5 Apr 24 2003 rmt0.5 > crw-rw-rw- 1 root system 22, 6 Apr 24 2003 rmt0.6 > crw-rw-rw- 1 root system 22, 7 Apr 24 2003 rmt0.7 > > You stated to (possibly) use rmt0.4 to enable more density on the tape. > > Do you know what the other rmt0 devices enable/disable/allow? > > Take care. > Clifton > <SNIPPED> Clifton Special File Rewind on Close Retension on Open Density Setting /dev/rmt* Yes No #1 /dev/rmt*.1 No No #1 /dev/rmt*.2 Yes Yes #1 /dev/rmt*.3 No Yes #1 /dev/rmt*.4 Yes No #2 /dev/rmt*.5 No No #2 /dev/rmt*.6 Yes Yes #2 /dev/rmt*.7 No Yes #2 Keith