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                                      fsmith AT hoovers DOT com
Sr. Systems Administrator                       Voice: 512-374-4673
Hoover's Online                                   Fax: 512-374-4501