Re: [RFC] ext3 documentation (lack of)

From: Ryan Cumming
Date: Wed Aug 18 2004 - 01:03:58 EST


On Tuesday 17 August 2004 17:59, you wrote:
> +commit=nrsec (*) Ext3 can be told to write all its data and metadata
> + every 'nrsec' seconds. The default value is 5 seconds.
> + This means that if you lose your power, you will lose,
> + as much, the latest 5 seconds of work. This default
> + value (or any low value) will hurt performance, but
> + it's good for data-safety. Setting it to 0 disables it.
> + Disabling it or setting it to very large values will
> + improve performance,

Setting commit to zero doesn't seem to disable it, judging from my local
2.6.8.1-mm1 source.

super.c has:
case Opt_commit:
if (match_int(&args[0], &option))
return 0;
if (option < 0)
return 0;
if (option == 0)
option = JBD_DEFAULT_MAX_COMMIT_AGE;
sbi->s_commit_interval = HZ * option;
break;

Where JBD_DEFAULT_COMMIT_AGE is defined to 5 in include/linux/jbd.h. So it
seems that setting it to zero will just set it to the default commit interval
of 5 seconds. Am I missing something?

-Ryan

Attachment: pgp00000.pgp
Description: PGP signature