Re: Amanda and dual tape libraries.
McGraw, Robert P wrote: I have a tape library (38) unit with one lto2 tape unit and one empty tape slot. I need to speed up our backups. One option is to purchase a second tape unit but not sure how Amanda works with a two tape drives. I searched the wiki for information but did not get any hits. I am going to upgrade to the latest Amanda version so the version should not be a problem. Can Amanda use multiple tape drives for a backup? I want to put complete backup files on a tape and not strip the tapes. If you are looking for speed and thinking of upgrading, then why not get an LTO4 drive to put in your library and switch to that? Assuming your backup system can drive it at full speed, that would be 3 times as fast as the LTO2 drive and would be able to read the LTO2 tapes. Of course, it would require transitioning to LTO4 tapes, but that's going to give you 4 times the capacity. Another option is larger holding disks (or a holding array), backing everything to there on its way to the tape. Do your backup reports indicate that the taping speed is the bottleneck? My library is AIT5, which isn't as fast as LTO. When a DLE is being written to tape, my system can drive the tape at full speed. However, the tape drive spends a lot of time idle, as the bottleneck on my system is traffic over the network and the busyness of the other servers that are being backed up. I have large enough spool drives that the backup activity is going to until it accumulates and is ready for taping. -- --- Chris Hoogendyk - O__ Systems Administrator c/ /'_ --- Biology Geology Departments (*) \(*) -- 140 Morrill Science Center ~~ - University of Massachusetts, Amherst hoogen...@bio.umass.edu --- Erdös 4
RE: Amanda and dual tape libraries.
I agree, but the caveat is that the planner will do its darndest to make full use of the extended capacity of the LTO4 cartridge. In my case, our backups went from between 5 and 8 hours with LTO2 tapes to well over 24 hours in some cases with the LOT4s - same DLEs. It took some fancy footwork to get it to a reasonable window (about the same length of time as with the 2s but some of the larger DLEs are forced to incremental on weekdays). This is so we can get the cartridges ready for pickup by our offsite storage provider. Steve Onotsky Server Support Technologist Broadridge Investor Communication Solutions, Canada 5970 Chedworth Way Mississauga ON L5R 4G5 Tel: (905) 507-5328 Fax: (905) 507-5312 Inet: steve.onot...@broadridge.com Quis custodiet ipsos custodes? - Juvenal, Satires, VI, 347 -Original Message- From: owner-amanda-us...@amanda.org [mailto:owner-amanda-us...@amanda.org] On Behalf Of Chris Hoogendyk Sent: May 14, 2009 12:53 To: amanda-users@amanda.org Subject: Re: Amanda and dual tape libraries. McGraw, Robert P wrote: I have a tape library (38) unit with one lto2 tape unit and one empty tape slot. I need to speed up our backups. One option is to purchase a second tape unit but not sure how Amanda works with a two tape drives. I searched the wiki for information but did not get any hits. I am going to upgrade to the latest Amanda version so the version should not be a problem. Can Amanda use multiple tape drives for a backup? I want to put complete backup files on a tape and not strip the tapes. If you are looking for speed and thinking of upgrading, then why not get an LTO4 drive to put in your library and switch to that? Assuming your backup system can drive it at full speed, that would be 3 times as fast as the LTO2 drive and would be able to read the LTO2 tapes. Of course, it would require transitioning to LTO4 tapes, but that's going to give you 4 times the capacity. Another option is larger holding disks (or a holding array), backing everything to there on its way to the tape. Do your backup reports indicate that the taping speed is the bottleneck? My library is AIT5, which isn't as fast as LTO. When a DLE is being written to tape, my system can drive the tape at full speed. However, the tape drive spends a lot of time idle, as the bottleneck on my system is traffic over the network and the busyness of the other servers that are being backed up. I have large enough spool drives that the backup activity is going to until it accumulates and is ready for taping. -- --- Chris Hoogendyk - O__ Systems Administrator c/ /'_ --- Biology Geology Departments (*) \(*) -- 140 Morrill Science Center ~~ - University of Massachusetts, Amherst hoogen...@bio.umass.edu --- Erdös 4 This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system.
RE: Amanda and dual tape libraries.
Onotsky, Steve x55328 wrote at 14:23 -0400 on May 14, 2009: I agree, but the caveat is that the planner will do its darndest to make full use of the extended capacity of the LTO4 cartridge. In my case, our backups went from between 5 and 8 hours with LTO2 tapes to well over 24 hours in some cases with the LOT4s - same DLEs. It took some fancy footwork to get it to a reasonable window (about the same length of time as with the 2s but some of the larger DLEs are forced to incremental on weekdays). This is so we can get the cartridges ready for pickup by our offsite storage provider. You can lie about your tape size in the tapetype, of course. You can even have different lies for different configurations. I've always wanted a knob to tell the scheduler to shoot for a smaller percentage of the total tape size, but to go ahead and use more if needed. Kind of an average target total size for the dumps. Maybe there is such a knob these days. I hope someone will say if there is. Lying about the tape size usually works fine. And it will go over that declared size if needed - if, for instance, some unexpected increase in size to a DLE happens after the estimate completes (or for whatever reason, the estimate is too low).
RE: Amanda and dual tape libraries.
Chris, Thanks for your input. I am using a 38 slot StorEdge C4 unit and one LTO2 tape drive. See some answers below. I just was looking to see if this is or could be done and if so how. With the virtual tape array maybe this will be mute. Robert _ Robert P. McGraw, Jr. Manager, Computer SystemEMAIL: rmcg...@purdue.edu Purdue UniversityROOM: MATH-807 Department of Mathematics PHONE: (765) 494-6055 150 N. University Street West Lafayette, IN 47907-2067 -Original Message- From: owner-amanda-us...@amanda.org [mailto:owner-amanda- us...@amanda.org] On Behalf Of Chris Hoogendyk Sent: Thursday, May 14, 2009 12:53 PM To: amanda-users@amanda.org Subject: Re: Amanda and dual tape libraries. McGraw, Robert P wrote: I have a tape library (38) unit with one lto2 tape unit and one empty tape slot. I need to speed up our backups. One option is to purchase a second tape unit but not sure how Amanda works with a two tape drives. I searched the wiki for information but did not get any hits. I am going to upgrade to the latest Amanda version so the version should not be a problem. Can Amanda use multiple tape drives for a backup? I want to put complete backup files on a tape and not strip the tapes. If you are looking for speed and thinking of upgrading, then why not get an LTO4 drive to put in your library and switch to that? Assuming your backup system can drive it at full speed, that would be 3 times as fast as the LTO2 drive and would be able to read the LTO2 tapes. Of course, it would require transitioning to LTO4 tapes, but that's going to give you 4 times the capacity. [McGraw, Robert P] I had looked into going to an lto4 but I am told by Sun that it is not supported on the C4. It does support the LTO3 but with the small increase of performance and the cost of LTO3 tapes I have decided to stay with the LTO2 for now. Another option is larger holding disks (or a holding array), backing everything to there on its way to the tape. [McGraw, Robert P] I have 500GB and seem to be plenty. I am planning on upgrading to Amanda 2.6.1 this month and start using the flush-threshold-dumped parameters. This should help. Also this summer I will have access to a 8TB array and will set up virtual tapes on this which will help. Do your backup reports indicate that the taping speed is the bottleneck? [McGraw, Robert P] My tape write speed is very close to the max for the LTO unit. My library is AIT5, which isn't as fast as LTO. When a DLE is being written to tape, my system can drive the tape at full speed. However, the tape drive spends a lot of time idle, as the bottleneck on my system is traffic over the network and the busyness of the other servers that are being backed up. I have large enough spool drives that the backup activity is going to until it accumulates and is ready for taping. -- --- Chris Hoogendyk - O__ Systems Administrator c/ /'_ --- Biology Geology Departments (*) \(*) -- 140 Morrill Science Center ~~ - University of Massachusetts, Amherst hoogen...@bio.umass.edu --- Erdös 4
Re: Amanda and dual tape libraries.
Onotsky, Steve x55328 wrote: I agree, but the caveat is that the planner will do its darndest to make full use of the extended capacity of the LTO4 cartridge. In my case, our backups went from between 5 and 8 hours with LTO2 tapes to well over 24 hours in some cases with the LOT4s - same DLEs. It took some fancy footwork to get it to a reasonable window (about the same length of time as with the 2s but some of the larger DLEs are forced to incremental on weekdays). This is so we can get the cartridges ready for pickup by our offsite storage provider. I don't get that at all. Doesn't make sense. Were there other things you changed? Or did you previously have much more designated for backup than your system and/or configuration could handle and the planner was always falling back? Maybe you had a setup that would result in 800G per day if it could, but you had a runtapes of 1, so Amanda was constantly forced to back up less than what it should have? Then you gave it LTO4 and it began to do what it should have all along? In my own case, I use much less than the capacity of my tapes. The designation of a dumpcycle of 1 week and runspercycle of 7 means I basically get 1 full per DLE per week, though that may vary slightly. I don't get how having a larger tape is going to affect that at all. -- --- Chris Hoogendyk - O__ Systems Administrator c/ /'_ --- Biology Geology Departments (*) \(*) -- 140 Morrill Science Center ~~ - University of Massachusetts, Amherst hoogen...@bio.umass.edu --- Erdös 4
Re: Amanda and dual tape libraries.
McGraw, Robert P wrote: Chris, Thanks for your input. I am using a 38 slot StorEdge C4 unit and one LTO2 tape drive. See some answers below. I just was looking to see if this is or could be done and if so how. With the virtual tape array maybe this will be mute. -Original Message- From: owner-amanda-us...@amanda.org [mailto:owner-amanda- us...@amanda.org] On Behalf Of Chris Hoogendyk Sent: Thursday, May 14, 2009 12:53 PM To: amanda-users@amanda.org Subject: Re: Amanda and dual tape libraries. Do your backup reports indicate that the taping speed is the bottleneck? [McGraw, Robert P] My tape write speed is very close to the max for the LTO unit. So the Amanda report gives you a tape write speed that looks good. But what about the Tape Time vs. Dump Time in the Amanda email report? For example, my report shows me an Avg Tp Write Rate that approaches what my drive is capable of. But, it also shows me a Tape Time of 1:24 and a Dump Time of 13:23. So, I'm somewhere around 1/10 of the backup period writing to tape (while still doing backups), and 9/10 of the backup period the tape is idle. Are you writing several tapes a night? -- --- Chris Hoogendyk - O__ Systems Administrator c/ /'_ --- Biology Geology Departments (*) \(*) -- 140 Morrill Science Center ~~ - University of Massachusetts, Amherst hoogen...@bio.umass.edu --- Erdös 4
Re: Amanda and dual tape libraries.
Chris Hoogendyk wrote: Onotsky, Steve x55328 wrote: I agree, but the caveat is that the planner will do its darndest to make full use of the extended capacity of the LTO4 cartridge. In my case, our backups went from between 5 and 8 hours with LTO2 tapes to well over 24 hours in some cases with the LOT4s - same DLEs. It took some fancy footwork to get it to a reasonable window (about the same length of time as with the 2s but some of the larger DLEs are forced to incremental on weekdays). This is so we can get the cartridges ready for pickup by our offsite storage provider. I don't get that at all. Doesn't make sense. Were there other things you changed? Or did you previously have much more designated for backup than your system and/or configuration could handle and the planner was always falling back? Maybe you had a setup that would result in 800G per day if it could, but you had a runtapes of 1, so Amanda was constantly forced to back up less than what it should have? Then you gave it LTO4 and it began to do what it should have all along? In my own case, I use much less than the capacity of my tapes. The designation of a dumpcycle of 1 week and runspercycle of 7 means I basically get 1 full per DLE per week, though that may vary slightly. I don't get how having a larger tape is going to affect that at all. Amanda gets wonky if your tape is much larger than your backups, or at least it does with 2.5.1p2. On one configuration with a 50GB tape (that can hold about two weeks of daily backups), Amanda was constantly promoting fulls trying to level out tape usage, but I really didn't want full backups every 2 or 3 days. If I had, I would have set dumpcycle to 2 or 3 days, but it was set to 5. Since I was trying to fill tapes by leaving dumps on the holding disk and only occasionally flush them to tape, I really didn't want all the incrementals constantly get promoted to fulls, wasting my holding disk space. Eventually I just forced it by setting maxpromoteday to 4 or 5 days, which solved the problem for me. Perhaps part of the issue was the result of having a couple of relatively larger DLEs and several smaller ones, making level tape usage impossible, no matter how they were arranged. Frank -- Frank Smith fsm...@hoovers.com Sr. Systems Administrator Voice: 512-374-4673 Hoover's Online Fax: 512-374-4501
