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Date: Fri, 10 Apr 2015 08:35:41 +0100
From: Arthur Chance <freebsd@qeng-ho.org>
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To: Warren Block <wblock@wonkity.com>, mfv <mfv@bway.net>
Subject: Re: Setting Trim _AFTER_ a New Install
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On 09/04/2015 22:27, Warren Block wrote:
> On Thu, 9 Apr 2015, mfv wrote:
>
>> Hello,
>>
>> I've recently installed FreeBSD r10.1 using bsdinstall and then loaded
>> a large number of programs and data.  After spending considerable time
>> on the installation I discovered that my SSD has TRIM which appears
>> to be quite useful. After some investigation I understand that it is a
>> simple flag that can be set after booting into single user mode.
>>
>> I hope my questions are  simple:
>>
>> If TRIM is enabled will it mess up the disk so that everything has to be
>> reinstalled?
>
> No, it will not harm the data.  That said, before running tunefs to
> enable it, make a backup.  Always make a backup.
>
>> If not, is there anything else I should be aware of?
>
> If you used ZFS-on-root, tunefs(8) and TRIM do not apply.  ZFS uses TRIM
> natively now, but I'm not sure if that was in 10.1 or only now in
> 10-STABLE.

I'm on 10.1-REL, it's got TRIM in zfs

root@arthur# sysctl vfs.zfs | grep trim
vfs.zfs.vdev.trim_on_init: 1
vfs.zfs.vdev.trim_min_active: 1
vfs.zfs.vdev.trim_max_active: 64
vfs.zfs.vdev.trim_max_bytes: 2147483648
vfs.zfs.vdev.trim_max_pending: 64
vfs.zfs.trim.enabled: 1
vfs.zfs.trim.txg_delay: 32
vfs.zfs.trim.timeout: 30
vfs.zfs.trim.max_interval: 1


-- 
Those who do not learn from computing history are doomed to
GOTO 1