Default boot/root filesystem

Chris Murphy lists at
Wed Sep 25 16:08:07 UTC 2013

On Sep 25, 2013, at 9:02 AM, Michael Cronenworth <mike at> wrote:

> Chris Murphy wrote:
>> So as it turns out some devices get really busy and slow down when TRIM is used, so not all devices are well suited for discard and therefore it's probably not a good idea for it to be set by default. It's also not enabled by default for ssds with btrfs either. And with dm-crypt there's a security concern in that it exposes massive zero'd holes on the device instead of current data being obscured by stale data.
> [citation needed]

> I have 4 SSDs of various manufacturers all used as root and boot drives. All use ext4 and have TRIM enabled. I have yet to experience any perceived slow downs.

OK but is that ext4 on the physical device or is LVM or RAID in between? I don't think TRIM passthrough to the physical device is default behavior with either LVM or md. If ext4 is directly on the physical device, all this says is you have four SSD models that aren't negatively impacted by TRIM. There are hundreds of models of SSDs.

Chris Murphy

More information about the devel mailing list