[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

[linux-lvm] BMT-LVM performance with snapshots



Kernel: 2.4.20
LVM: 1.0.6 with kernel patched(VFS-lock and lvm-1.0.6)
CPU: PIII 1.4
RAM: 512M

This is the output from bonnie++ with lv only and with lv + snapshot

Version 1.03 ------Sequential Output------ --Sequential Input- --Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
lv_wo_snap 2G 78505 32 41745 27 151742 41 435.4 1
lv_wo_snap 2G 75501 31 40277 25 150466 42 436.8 1
lv_wo_snap 2G 73933 29 41213 26 150052 41 433.4 1
lv_wo_snap 2G 76434 30 40980 26 147544 41 399.0 0
lv_with_sn 2G 1367 0 10196 6 128362 35 437.4 1
------Sequential Create------ --------Random Create--------
-Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files:max:min /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
lv_wo_snap 16 1669 17 +++++ +++ 2532 23 1464 17 +++++ +++ 475 5
lv_wo_snap 16 1572 17 +++++ +++ 2265 24 1431 14 +++++ +++ 457 5
lv_wo_snap 16 1481 17 +++++ +++ 2100 22 1405 15 +++++ +++ 478 6
lv_wo_snap 16 1536 16 +++++ +++ 2286 23 1513 17 +++++ +++ 458 5
lv_with_sn 16 625 8 +++++ +++ 2333 26 1174 12 +++++ +++ 460 5



After making snapshots for a LV, the write performance goes down from 75M/s to 1.3M/s.


Something must be wrong in LVM.


_________________________________________________________________
The new MSN 8: smart spam protection and 2 months FREE* http://join.msn.com/?page=features/junkmail





[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]