[Top] [All Lists]

Re: XFS and nobarrier with SSDs

To: Martin Steigerwald <martin@xxxxxxxxxxxx>
Subject: Re: XFS and nobarrier with SSDs
From: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Date: Mon, 14 Dec 2015 01:58:23 -0800
Cc: Georg Sch?nberger <g.schoenberger@xxxxxxxxxx>, Jens Axboe <axboe@xxxxxxxxx>, Jeff Moyer <jmoyer@xxxxxxxxxx>, Linux FS-Devel <linux-fsdevel@xxxxxxxxxxxxxxx>, Linux Block mailing list <linux-block@xxxxxxxxxxxxxxx>, XFS mailing list <xfs@xxxxxxxxxxx>
Delivered-to: xfs@xxxxxxxxxxx
In-reply-to: <3911767.qVqsL1TcMv@merkaba>
References: <E127700EFE58FD45BD6298EAC813FA42020D8173@xxxxxxxxxxxxxxxxxxxxxx> <3496214.YTSKClH6pV@merkaba> <566E6524.6070401@xxxxxxxxxx> <3911767.qVqsL1TcMv@merkaba>
User-agent: Mutt/1.5.23 (2014-03-12)
On Mon, Dec 14, 2015 at 09:38:56AM +0100, Martin Steigerwald wrote:
> Is it safe to use XFS (or any other filesystem) on enterprise SSDs with Power 
> Loss Protection (PLP), i.e. some capacitor to provide for enough electricity 
> to write out all data in DRAM to flash after a power loss, with a reordering 
> I/O scheduler like CFQ?

If the device does not need cache flushes it should not report requiring
flushes, in which case nobarrier will be a noop.  Or to phrase it
differently:  If nobarrier makes a difference skipping it is not safe.

<Prev in Thread] Current Thread [Next in Thread>