Messages in this thread | | | Subject | Re: softupdates and ext2 | From | Mats Lofkvist <> | Date | 31 Mar 1999 14:20:52 +0200 |
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Trevor Johnson <trevor@jpj.net> writes:
> > I made some benchs and it seems rather fast (about 5 to 10% slower than > > the async mount, which is what Linux does). > > It does that by default, but (for ext2 at least) you can mount with the > "sync" option to have at least the metadata written synchronously. It is > much slower than the asynchronous way, but I would do it if the unclean > shutdowns couldn't be prevented.
The reason the "sync" option is so slow is because it makes _all_ writes synchronous. The default of sync metadata / async userdata used by most Unixen is not noticeably slower than async except for large metadata operations like removing large directory trees.
E.g. when testing with bonnie on a system using sync/async as default, there is no visible difference from using "async". But when using "sync" on a Linux system, the write performance dropped to ~80kbyte/s (on a disk that writes ~8Mbytes/s using "async").
_ Mats Lofkvist mal@algonet.se
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