On Fri, Jul 25, 2008 at 01:18:40PM -0400, Brian Cuttler wrote: > > We have a Solaris E250 amanda server backing up two T1000 servers, > also Solaris, hosting Lotus Notes. > > Over time, we decided on HW compression, runs where long but they > completed pretty reliably at the same time every day. > > We tried an experiment, since we hadn't really tried SW compression > since we upgraded the client systems, we used SW-client compression > and removed the HW compression. Runs jumped to 22+ hours, but we where > not seeing the work area filled (the data was smaller, and it was taking > longer to get to us). > > So I increased the inparallel parameter, which of course ramped up > the load on the clients even further. > > The question of which version of Gzip to run arose, we had a fairly > old version and there is a newer-Sun version available, just didn't > know how version sensitive we where. I know version of gzip (which > we use on some partitons on these clients) is very version specific. > > Is there a list of tested/approved gzip versions ? I didn't see one > but may not have dug deep enough. > > Current gzip > $ /usr/local/bin/gzip -V > gzip 1.2.4 (18 Aug 93) > > Proposed gzip > $ /usr/bin/gzip -V > gzip 1.3.5 > (2002-09-30) > Copyright 2002 Free Software Foundation >
One thing to check is whether you have specified "best" for your compression. Gzip allows you to select from 9 levels of compression, trading cpu time (and wall time) for extra compression. Amanda allows you to select "fastest" (aka level 1), "best" (level 9) or default which is level 6. I just ran a quick test on an 11MB text only file. Level 9 took three times as long as level 1. Yet level 1 gave 83% of the compression of level 9. I like default level 6 which took 1.8 times as long as level 1 and gave 97% of the compression of level 9. BTW I also ran bzip2 on the same file. It did 60% better than gzip level 9, but took nearly 22 times as long as gzip level 1. -- Jon H. LaBadie [EMAIL PROTECTED] JG Computing 12027 Creekbend Drive (703) 787-0884 Reston, VA 20194 (703) 787-0922 (fax)
