<div style="font-size:10pt; font-family:Gulim;"><pre style="line-height: normal;">On Wed, Jan 08, 2014 at 09:56:19PM +0900, trex wrote:
>><i> I built HA iSCSI targets with ocfs2+dual primary.(Ubuntu 13.04)
</i>>><i> Each node has SSD raid with mdadm level0.
</i>>><i> few days later, ocfs2 became frozen sometimes.
</i>><i>> I figured out that it happens without TRIM.
</i>>><i> But, I couldn't TRIM ssd raid because ocfs2 only supports offline TRIM(fstrim) and drbd 8.4.4 only supports online TRIM(discard).
</i>>><i> Then, HOW CAN I TRIM SSDs on DRBD+OCFS2?
</i>
> <i>Uhm, to the linux block layer (including DRBD), there is no difference
<span style="font-family: Gulim; font-size: 10pt;">> </span>between what you call "online" or "offline" here. And whether you call
<span style="font-family: Gulim; font-size: 10pt;">> </span>it trim or discard or unmap, again, to the linux block layer, it is all
<span style="font-family: Gulim; font-size: 10pt;">> </span>the same thing. The differences are implementation details in the low
<span style="font-family: Gulim; font-size: 10pt;">> </span>level hardware drivers (scsi, fusion, etc.)
> Did you actually try it?
> What happened?
> Error message?
> Logs?
> Are you sure your SSD *and* MD properly support and propagate the
> discard capabilities and requests?</i></pre><pre style="line-height: normal;">First, ocfs2 doesn't have discard mount option.</pre><pre style="line-height: normal;">It means you have to run FSTRIM for TRIM your ssd devices.</pre><pre style="line-height: normal;">And it actually works.</pre><pre style="line-height: normal;">Some other filesystems are supporting automatic TRIM with discard option.(ex. btrfs, ext4 )</pre><pre style="line-height: normal;"><br></pre><pre style="line-height: normal;">Second, you cannot TRIM on DRBD devices with FSTRIM.</pre><pre style="line-height: normal;">There's a error message:</pre><pre><span style="line-height: normal;">"fitrim ioctl failed operation not supported"<br></span></pre><pre>Without DRBD, you can run FSTRIM on any filesystem.</pre><pre><br></pre><pre>So question is </pre><pre>'How trim filesystem on drbd which doesn't support discard mount option?<span style="line-height: 1.5; font-family: Gulim; font-size: 10pt;">'</span></pre><pre><br></pre><pre><br></pre><pre style="line-height: normal;"><br></pre></div>
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