> BTW, file system journal may be not enough for reliable maintenace of > encrypting whole files.
AFAIK, while changed data are being written to filesystem, SQLite Cypher (as a internal DB layer ) reencrypts only affected table page not reincrypts whole file system (or a mounted large file) as NT5+ & loopback approaches mean to do. May be we need more statistic, but currently me'm very afraid of encrypting file system - it looks like an archive with a single byte corrupted & no data redundancy to recover resulting in full garbage. It looks too risky. 2011/11/26, IvankoB for-mse <ivankob4m...@gmail.com>: >>I mean Firebird with switched on highest level of page disk write >> syncing not Postgres. > > We use PostgreSQL with fsync=on. Me guess. it's the same. > >> Still a problem with ext4? > What a difference ? What will be best is the absence of need in manul > FSCK runs :) > > BTW, file system journal may be not enough for reliable maintenace of > encrypting whole files. EXt3 is an example of such when page of file > system != page being encrypted. The most fragile situtaion is being > mounted & written while power fails. > >>Although I don't know if Firebird actually is more >> reliable with aborted disk operations than Sqlite. > > Since FB & SQlite 3 don't have the facility to write user-defined > functions easily then me consider them equal (though yesterday me knew > that SQlite 3 seems to provide such). But You're right - for SQlite we > have some statictic & for FB-embedded not. > > > 2011/11/26, Martin Schreiber <mse00...@gmail.com>: >> On 11/26/2011 05:08 PM, IvankoB for-mse wrote: >>>> Are you sure Sqlite can be used with unreliable power supply? >>> >>> Yes (more clear - me don't see an alternative) - we have had only one >>> data failure amongst 5 machines for 3 years with 3..10 general power >>> failures per week. And even this failure was most probably virus >>> related - that virus taped into file i/o. >>> >>>> Maybe better to use an embedded or local Firebird server? >>> >>> It's our current solution at city-level for years (150 work places >>> replicating to a single server). For the province (where there're >>> very little russian, german, tatar & korean - IT-devoted nation >>> people), it doesn't fit since 1) needs VERY qualified personnel to >>> recover (fsck, pg_dump/psql,..) >> >> I mean Firebird with switched on highest level of page disk write >> syncing not Postgres. >> >> 2) from years experience, these >>> backends don't like power failures even with fsync swithced on (broken >>> sequences, corrupted system tables = needs an EXTREMELY qualified >>> PC-doctor, etc - we have approx 1..3 DB failures per week in the >>> city). >>> And they can only be encrypted on file-system level - very-very >>> dangerous as to full data loss in case of mounted filesystem while >>> power fails etc. >> >> Still a problem with ext4? >> >>> And since SQlite3 maintain small-sized (& not related) files then the >>> probablity of data failure due to power failure is much less than for >>> large file DB servers. And these small files (or more probably a >>> single file) are easy for DB backup - the ROZNITSA solution performs >>> it every program run and by user defined schedule. >>> >> Agreed. With an embedded Firebird server instead Sqlite the files would >> not be bigger. Although I don't know if Firebird actually is more >> reliable with aborted disk operations than Sqlite. >> >> Martin >> >> ------------------------------------------------------------------------------ >> All the data continuously generated in your IT infrastructure >> contains a definitive record of customers, application performance, >> security threats, fraudulent activity, and more. Splunk takes this >> data and makes sense of it. IT sense. And common sense. >> http://p.sf.net/sfu/splunk-novd2d >> _______________________________________________ >> mseide-msegui-talk mailing list >> mseide-msegui-talk@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/mseide-msegui-talk >> > ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-novd2d _______________________________________________ mseide-msegui-talk mailing list mseide-msegui-talk@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mseide-msegui-talk
