Обсуждение: Data folder in differnet filesystem

I have 2 doubts related to Filsesytem and Postgres data folder

1.Currently in CentOS,  our postgres data folder is in single filesystem. Is there any possibility to have a single data folder of single postgres in more then one file system.
2.I am having three big DB, is it possible to have a data of each DB in different file system. so if i want to add a DB to postgre i will mount a drive (filesystem ) and point that location for the postgres to use that space.
  for eg
Filesystem Mounted on
/dev/hda3      /data/db1            for DB1
/dev/hda4      /data/db2            for DB2

thanks in advance


Arvind S



"Many of lifes failure are people who did not realize how close they were to success when they gave up."
-Thomas Edison

In response to S Arvind :
> I have 2 doubts related to Filsesytem and Postgres data folder
>
> 1.Currently in CentOS,  our postgres data folder is in single filesystem. Is
> there any possibility to have a single data folder of single postgres in more
> then one file system.

Don't understand ...


> 2.I am having three big DB, is it possible to have a data of each DB in
> different file system. so if i want to add a DB to postgre i will mount a drive
> (filesystem ) and point that location for the postgres to use that space.
>   for eg
> Filesystem Mounted on
> /dev/hda3      /data/db1            for DB1
> /dev/hda4      /data/db2            for DB2

Sure, use different tablespaces.

http://www.postgresql.org/docs/8.4/static/manage-ag-tablespaces.html


Andreas
--
Andreas Kretschmer
Kontakt:  Heynitz: 035242/47150,   D1: 0160/7141639 (mehr: -> Header)

On 2009-09-03, S Arvind <arvindwill@gmail.com> wrote:
> --001636ed7465170dcf0472ab404d
> Content-Type: text/plain; charset=ISO-8859-1
>
> I have 2 doubts related to Filsesytem and Postgres data folder
>
> 1.Currently in CentOS,  our postgres data folder is in single filesystem. Is
> there any possibility to have a single data folder of single postgres in
> more then one file system.
> 2.I am having three big DB, is it possible to have a data of each DB in
> different file system. so if i want to add a DB to postgre i will mount a
> drive (filesystem ) and point that location for the postgres to use that
> space.
>   for eg
> Filesystem Mounted on
> /dev/hda3      /data/db1            for DB1
> /dev/hda4      /data/db2            for DB2
>

to be able to mount and unmount databases you will need to use
separate "clusters",

Jasen Betts wrote:
> On 2009-09-03, S Arvind <arvindwill@gmail.com> wrote:
> > --001636ed7465170dcf0472ab404d
> > Content-Type: text/plain; charset=ISO-8859-1
> >
> > I have 2 doubts related to Filsesytem and Postgres data folder
> >
> > 1.Currently in CentOS,  our postgres data folder is in single filesystem. Is
> > there any possibility to have a single data folder of single postgres in
> > more then one file system.
> > 2.I am having three big DB, is it possible to have a data of each DB in
> > different file system. so if i want to add a DB to postgre i will mount a
> > drive (filesystem ) and point that location for the postgres to use that
> > space.
> >   for eg
> > Filesystem Mounted on
> > /dev/hda3      /data/db1            for DB1
> > /dev/hda4      /data/db2            for DB2
> >
>
> to be able to mount and unmount databases you will need to use
> separate "clusters",

No, you can also use tablespaces for this.  Just create a directory
inside /data/db1 (say /data/db1/ts) and then CREATE TABLESPACE ts_for_db1
LOCATION '/data/db1/ts'.  Then you can create the database in there.

--
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.

On 2009-09-07, Alvaro Herrera <alvherre@commandprompt.com> wrote:
> Jasen Betts wrote:
>> On 2009-09-03, S Arvind <arvindwill@gmail.com> wrote:
>> > --001636ed7465170dcf0472ab404d
>> > Content-Type: text/plain; charset=ISO-8859-1
>> >
>> > I have 2 doubts related to Filsesytem and Postgres data folder
>> >
>> > 1.Currently in CentOS,  our postgres data folder is in single filesystem. Is
>> > there any possibility to have a single data folder of single postgres in
>> > more then one file system.
>> > 2.I am having three big DB, is it possible to have a data of each DB in
>> > different file system. so if i want to add a DB to postgre i will mount a
>> > drive (filesystem ) and point that location for the postgres to use that
>> > space.
>> >   for eg
>> > Filesystem Mounted on
>> > /dev/hda3      /data/db1            for DB1
>> > /dev/hda4      /data/db2            for DB2
>> >
>>
>> to be able to mount and unmount databases you will need to use
>> separate "clusters",
>
> No, you can also use tablespaces for this.  Just create a directory
> inside /data/db1 (say /data/db1/ts) and then CREATE TABLESPACE ts_for_db1
> LOCATION '/data/db1/ts'.  Then you can create the database in there.

If later disks aren't present you will not be able to do many things
(like add or remove roles)

True. S. did not ask for that feature explicily (only about adding databases)