7 апреля 2015 г. 20:25:45 CEST, Jason Matthews <[email protected]> пишет: > > >On 4/7/2015 11:07 AM, Jim Klimov wrote: >> >> As for inflation - whenever you have smaller zfs allocations, such as >those "tails" from blocks sized not power of 2 thanks to compression, >they become a complete minimal "recordsize" block such as 4k or 8k as >native to your drives, with trailing zero-padding. Some metadata blocks >may also fall into this category, though for larger files these are >clustered at 16kb(?) chunks. You also have less uberblocks in the >fixed-size ring buffer of zpool labels. > >I am not sure tails justifies the inflation. I can accept some >increased >utilization from tails but this is totally out of line. > >Here is a 512b system of a database master. >root@shard035a:/home/postgres/data/base/16414# du -hs . > 203G . >root@shard035a:/home/postgres/data/base/16414# ls -l |wc -l > 4109 > >203GB and 4109 files. > >Here is the slave that I built from the master yesterday. They should >be >nearly identical. > >root@shard035b:/home/postgres/data/base/16414# du -hs . > 474G . >root@shard035b:/home/postgres/data/base/16414# ls -l |wc -l > 4081 > >My feeling is there are not enough tails in 4100 files to consume 271GB > >of storage. I dont understand what is going on just yet. > >j. > > > > >> On the upside, if your ssd does compression, these zeroes will in >effect likely count toward wear-leveling reserves ;) With hdds this is >more of a lost space as compared to 512-byte sectored disks. However >this just become similar to usage on other systems (ext3, ntfs) >typically with 4k clusters anyway. So we're told to not worry and love >the a-bomb ;) >> > > > >_______________________________________________ >openindiana-discuss mailing list >[email protected] >http://openindiana.org/mailman/listinfo/openindiana-discuss
Also, how did you build the slave? Binary file copy? Zfs send? Import from sql/dump files? Are compression/copies/recordsize etc. settings the same on two dataset contents? -- Typos courtesy of K-9 Mail on my Samsung Android _______________________________________________ openindiana-discuss mailing list [email protected] http://openindiana.org/mailman/listinfo/openindiana-discuss
