Re: [GENERAL] PostgreSQL on a CompactFlash
Am 2008-01-31 12:03:00, schrieb Andre Nieder: > Hello, > > > > we like to use PostgreSQL in an embedded system that runs - don't laugh > - on a compact flash. I have this too... > Therefore we need to know how often PostgreSQL will write to the disc. PostgreSQL in a normal installation of, e.g. a 8 GByte HighSpeed CF-Card will kill your card in less then one month mayb arround two weeks. > Once our system is configured there are very little changes to the > database. Like here... > We have some tables in memory and some stored on the cf. > > If we change a table in memory, will PosgreSQL access the cf? Configure the PostgreSQL as needed and then create a RAM-Disk for the data/ directory. shutdown the PostgreSQL and tar the whole RAM-Disk and before you start uncompress it... > As you know a cf card has not an unlimited amount of accesses... :-) > So is there any reason that should prevent us from using PostgreSQL in > combination with a compact flash? Maybe the limit of the Memory of your system. I am using a 3Ware 3W85xx-8 with three 1 GByte Cards (Raid-1 + Hotfix), one singel 1 GByte Card (/var/log) and four 8 GByte Cards (Raid-5 + Hotfix) for the Data (the Postgresql.tar.gz and static data) The TAR Archive is around 5 GByte (PostgreSQL has already compressed the Stuff) and I was forced to install 12 GByte of Memory. Thanks, Greetings and nice Day Michelle Konzack Systemadministrator Tamay Dogan Network Debian GNU/Linux Consultant -- Linux-User #280138 with the Linux Counter, http://counter.li.org/ # Debian GNU/Linux Consultant # Michelle Konzack Apt. 917 ICQ #328449886 50, rue de Soultz MSN LinuxMichi 0033/6/6192519367100 Strasbourg/France IRC #Debian (irc.icq.com) signature.pgp Description: Digital signature
Re: [GENERAL] PostgreSQL on a CompactFlash
Hi Andre, As you know a cf card has not an unlimited amount of accesses… Do we really know? Or are we just repeating the same story we were told once? I know that technically speaking you are right but the media have smart contollers to avoid problems with this fact. I remember reading in a german computer journal that they were trying really hard to write a USB stick to death but gave up after 16 000 000 write cycles to the same logical adress without any error. Is there a theoretical limit or a practical one? I'd be really interested in a real world test - does postgres work on as cf-card/usb-stick and how long? If anyone has got numbers - please let me know. Regards, Brar ---(end of broadcast)--- TIP 2: Don't 'kill -9' the postmaster
Re: [GENERAL] PostgreSQL on a CompactFlash
Am Donnerstag, 31. Januar 2008 schrieb Andre Nieder: > So is there any reason that should prevent us from using PostgreSQL in > combination with a compact flash? I suggest you review the previous discussions on this topic. Search for "compact flash" on archives.postgresql.org. You will find that PostgreSQL very write-happy and you might have some work to do. -- Peter Eisentraut http://developer.postgresql.org/~petere/ ---(end of broadcast)--- TIP 2: Don't 'kill -9' the postmaster
[GENERAL] PostgreSQL on a CompactFlash
Hello, we like to use PostgreSQL in an embedded system that runs - don't laugh - on a compact flash. Therefore we need to know how often PostgreSQL will write to the disc. Once our system is configured there are very little changes to the database. We have some tables in memory and some stored on the cf. If we change a table in memory, will PosgreSQL access the cf? As you know a cf card has not an unlimited amount of accesses... So is there any reason that should prevent us from using PostgreSQL in combination with a compact flash? Andre
