On Mon, Mar 11, 2002 at 08:11:32PM +1100, Jeff Waugh wrote: > <quote who="Bill Taylor"> > > > RH 7.1 uses ext2; 7.2 offers ext3 as default. Does anyone have opinions > > or preferences? > > ext3 by a long shot; by default, it uses ordered writes (a kind of > journalling), so your data is safer, and you don't have to wait through > laborious fscks when you start up. You can also turn on full data > journalling, which, whilst slower, is safer again (it's also oddly faster > for some kinds of operations).
Echo sentiments of delight for ext3. Some things to be aware of though. ext3 helps protect your file system. The bigger picture includes protecting your data (e.g. backups), and may include protecting your transactions. Transactions can involve several operations, and you want them work properly. This involves a set of criteria called ACID : A = atomicity, or "all or nothing". Either all elements of the transaction are done or none. C = consistency. It is fully determinate, not producing different results for the same conditions I = Isolation. The transaction is unaffected by other transactions or operations in the system. D = durability. Results must be permanent. Ext3 really only helps support the last. What most people seem to do is use a database with transaction level locking support to achieve this. This may be overkill, and at the same time not enough. Remember when the big problem with MySQL was no support for transaction locking? If database support is not enough, you may have to use something else, e.g. transaction monitors, or transaction processing systems. Sorry for straying into something you asked nothing about, but this is now another hobby-horse of mine. (Hears voice: You've got a bloody room full of half broken hobby-horses in there Jamie. Why don't you do something practical with them or take them to the dump). Databases are like the proverbial hammer. Everyone uses them because they know them. But they may not be completely appropriate, sort of like every problem becoming how to drive a nail. Jamie -- SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
