>> > With >> > >> > Maximum File Size = 5G >> > Maximum Block Size = 262144 >> > Maximum Network Buffer Size = 262144 >> > >> > I get up to 150M MB/s while despooling to LTO-4 drives. Maximum File >> > Size gave me some extra MB/s, I think it's as important as the >> > Maximum Block Size. >> > >> > >> thanks for providing this hints. just searching why my lto-4 is writing >> just at 40mb/s. will try them out! >> >> searching the "Maximum File Size" in the manual I found this: >> >> If you are configuring an LTO-3 or LTO-4 tape, you probably will want >> to set the Maximum File Size to 2GB to avoid making the drive stop to >> write an EOF mark. >> >> maybe this is the reason for the "extra mb/s". > > Modifying the Maximum Block Size to more than 262144 didn't change much > here. But changing the File Size did. Much.
I found a post from Kern saying that Quantum told him, that about 262144 is the best blocksize - increasing it would increase error rate too. > > Anyway, 40 MB/s seems a bit low, even with the defaults. Before tuning > our setup I got ~75 MB/s. Are you spooling the data to disk or writing > directly to tape? yes, i was surprised too that it is that slow. I'm spooling to disk first (2x 1TB disk as RAID0, dedicated to bacula for spooling). i will also start a sequential read test to check if the disks are the bottleneck. The slow job was the only one running. watching iotop i saw the "maximum file size" problem: it stops writing after 1 GB (default file size) and writes to the DB and then continues writing. so for a LTO-4 it stops nearly 800 times until the tape is full. - Thomas ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
