Is the checkpoint interval adjustable?
I believe 30 sec is the default for the checkpoint interval. Is this adjustable?
Quoted 1 line · Mike Audia
I believe 30 sec is the default for the checkpoint interval. Is this adjustable?
It doesn't look like it. It looks like it's implemented with raw '30's in the code.
delay = HZ * 30;
...
(now < cur->start_time || now - cur->start_time <30)) {
If you want more frequent forced commits you could always syncfs() regularly from userspace, I suppose.
- z
Quoted 5 lines · Mike Audia
I believe 30 sec is the default for the checkpoint interval. Is this adjustable? --
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Just curious: What would be the benefit of increasing the checkpoint interval?
As far as I understood it would not decrease write load on the drives because it will only update a few pointers and probably increase the generation number...
Greetings,
Kai
Quoted 9 lines · Kai Krakow
Quoted 5 lines · Mike Audia
I believe 30 sec is the default for the checkpoint interval. Is this adjustable? --
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More majordomo info at http://vger.kernel.org/majordomo-info.htmlJust curious: What would be the benefit of increasing the checkpoint interval?
Laptops typically spin down disks to save power. If btrfs forces a write every 30 second, you have to spin it back up.
--
Torbjørn
Quoted 7 lines
As far as I understood it would not decrease write load on the drives because it will only update a few pointers and probably increase the generation number...
Greetings,
Kai
Quoted 4 lines · Torbjørn
Quoted 2 lines
Just curious: What would be the benefit of increasing the checkpoint interval?
Laptops typically spin down disks to save power. If btrfs forces a write every 30 second, you have to spin it back up.
I'd expect btrfs not to write to the disk when a checkpoint is reached and no writes occurred to the filesystem meanwhile... Could some developer shed some light on this?
IMHO if this is true, there is no point in increasing the checkpoint interval... Thoughts?
Regards,
Kai