TRIM and changing mount options

aurfalien aurfalien at
Wed Jul 24 03:49:51 UTC 2013

On Jul 23, 2013, at 7:55 PM, Dan Nelson wrote:

> In the last episode (Jul 23), aurfalien said:
>> I've some what blindly followed a how to on installing FreeBSD 9.1 on a
>> ZFS mirror.
>> My typing is horrid so I simply ssh'd to a live CD env and pasted line by
>> line as per the how to found here;
>> All is well, no issues with replacing disks, testing failures etc...
>> But seeing that my system drives are SSDs, I thought to perhaps add
>> noatime, etc...  to avoid slow downs common in excessive SSD usage.
>> However my fstab is only mounting swap partitions and I have no idea how
>> my file system is being mounted :)
>> Also, I would like to use tunefs in finding if I have TRIM enabled as I
>> did load it via boot.conf
>> I kinda feel like I'm willy nilly adding load lines w/o seeing if I
>> actually have the TRIM patch installed :)
>> At any rate, could some one;
>> a) Explain how I am loading my file system as I'm used to fstab?
>> b) How to run tunefs on my zroot
>> c) How to determine if I actually have the needed TRIM support in my kernel
> ZFS automatically opens pools that were previously imported ( this info is
> stored in /boot/zfs/zpool.cache ), and automatically mounts any filesystems
> that have a mountpoint specified, so fstab isn't needed.
> Tunefs is a UFS-only command,

Read the man page after sending, sorry for this.

I try not to post obvious stuff, meaning ones that you can 'man' :)

> so it won't help you here.  Most zfs
> properties can be set on the fly with the "zfs" command.  You can disable
> atime on your ZFS filesytem with "zfs set atime=off zroot".  All the
> filesystems created in zpool will inherit the value.
> I'm not sure if there's a way to query TRIM status on arbitrary geom
> providers, but you can see whether zfs successfully sent any TRIM requests
> by watching the output of "sysctl kstat.zfs.misc.zio_trim".  If
> .zio_trim.success increments and .unsupported (or .failed) doesn't, then you
> know that it's working.

Looks like I don't have it.

I keep reading that I must download the patch and make it which is not an issue.

But I can't seem to find it.

So I got this;

But I keep reading that I need PJDs zfs patch set in addition.

I've been reading this;

Do you know how I can pull the source for this?

I've dl'd the 9.2 beta in hopes to check its src and see if its there.

Looks like all I really need is the current rel.

- aurf

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