Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

It's my understanding that, without correctly disabling OS-level and drive-level caching, there is a chance that in case of system failure the Write-Ahead Log might not be saved correctly and in fact might get corrupted, possibly preventing data recovery.

I've already made sure that


however I was unable to make any configuration changes with hdparm since I get the following:

$ sudo htparm -I /dev/xvdf

 HDIO_DRIVE_CMD(identify) failed: Invalid argument

Looks like that option is not available in the kind of setup you get in EC2.

Am I missing anything here? Are there any other obvious caches I have to disable to ensure the WAL's safety?

share|improve this question
add comment

Know someone who can answer? Share a link to this question via email, Google+, Twitter, or Facebook.

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.