Subject Re: [firebird-support] why Blob is so slow ?
Author Alexandre Benson Smith
Em 19/4/2012 16:28, Carlos H. Cantu escreveu:
> LC> It is a little amazing at time when some things work fast on one machine and a
> LC> lot slower on another, but the sort of problem you are seeing I would check that
> LC> there is not a problem with the hard disc. I've seen that sort of effect when
> LC> the controller is having trouble reading a disk. It WILL read the data
> LC> eventually, but keeps winding the heads back to '0' and repositioning for each
> LC> block read. Replacing the hard disk and restoring the data invariably cleared
> LC> the problem. Had it a couple of time now - 'Maxtor' discs have been stripped
> LC> from all my customer machines now!
> My guess is that the time differences are also related to the
> configuration of the file system used in his linux server (ie: barrier
> and other params). Kouzmenko and me tested in Windows machines.
> Carlos
> Firebird Performance in Detail -
> -

I am still doing some tests to try to identify the culprit.

I tested on another linux machine and the restore is under 3s, but I
can't compare because this machine uses SCSI disks on RAID, and mine is
a simple (and pretty old) SATA disc.

I will test on some real hardware and report back.

I had ruled out hardware/file system too fast, thats the reason I posted
the original message, the reason I ruled out hardware/file system
configuration is because I noted the slowdown on a client site and then
tested on my server I noted the same speed problem... But I think that
both servers (mine and my customer) have something weird (perhaps
filesystem options as pointed out by Carlos).

Unfortunatelly I had no remote access to that server.

Thanks for all the input and to Carlos and Dmitry for the time to
perform the tests.

see you !