Re: Restarting DB after moving to another drive - Mailing list pgsql-general

Hi Daniel:

On Mon, May 11, 2015 at 5:30 PM, Daniel Begin <jfd553@hotmail.com> wrote:
> How big? According to PgAdmin my personal database is about 2TB...

I do not know what pgAdmin reports, I was thinking in how bick a dump
( using -Fc, which compresses on th fly ) is, to see wheter you can
restore.

> How critical? Well, about a year of work!-)

Well, my fault. I know its valuable, or you wouldn't be bothering with
all of this. By critical I meant if you can take it offline for the
time needed to do a dump/restore, but I suppose after all this time
you have a problem with this approach.

> Francisco wrote: "just did a stop/cp/change pgdata /restart, I suppose windows must have comparable ways"
> This is what I have just tried when I got “Could not read symbolic link “pg_tblspc/100589”: Invalid argument”

I do not know windows, but I suppose you must check this error, I
mean, check the link in the original and the copy and see if they look
right ( ls -l does it in linux, I suppose the windows ls or whatever
tool you use to list a directory in windows can do it too ).

> Considering both drives are identical, could an image backup have done the job properly instead of a plane copy?

I know the builtin windows copy ( in cmd ) was not good copying
complex setups. cp for windows did it in my times, but as I say it was
a long time ago and windows is too complex for me. I also do not know
what an image backup is. In Linux I've done a sector-by-sector copy (
only on nearly full disks, otherwise cp is faster ) to a bigger disks
and the OS didn't notice after the swap ( and neither Postgres ). On
identical disks, a sector copy should work, but I wouldn't be
surprised if windows kept some kind of info and need some other
adjustement.

Anyway, what I mean is a normal copy should suffice, but windows is
complex and a normal copy is very difficult to make ( at least for me
). But the error says it is getting a problem with a readlink. The
first thing should be checking it, it is simple in Linux, you just do
ls l on both of them and you are done, you even have a readlink
program to use in scripts, I assume windows has a similar command,
just check it. Given the error i would bet for an EINVAL which
normally is due to the named file ( pg_tblspc/100589 ) not being a
symlink, the windows equivalent to ls -l should tell you that ( my
thought is somehow it is a directory, or a plain file, but you should
be able to find it easily ). I cannot tell you more, also bear in mind
I abandoned windows in 2001 an use pgadmin only for seeing queries in
a grid, I do all my admin tasks with psql/pg_dump/pg_restore, so I
cannot tell you zilch about windows or pgadmin specific stuff.

Regards.
    Francisco Olarte.