> -----Original Message----- > From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid- > owner@xxxxxxxxxxxxxxx] On Behalf Of Robin Hill > Sent: 23 October 2009 10:38 > To: linux-raid@xxxxxxxxxxxxxxx > Subject: Re: md software raid > > On Fri Oct 23, 2009 at 02:11:09AM -0700, ian.d wrote: > > > > > hello > > > > As a newbie to Linux kernel etc. > > > > How do you tell which version of md software raid is included in a > > specific kernel version? > > Is there a command to run which will return this info? > > Is it possible to install different versions of md in different > kernels? > > > There's two separate components to Linux software RAID - the md code in > the kernel, and the mdadm application which interfaces with it. I very > much doubt the kernel code is versioned at all, other than by the > kernel version (or GIT version). The mdadm application is versioned, > and you can get the installed version by running 'mdadm -V'. > > Some of the mdadm functionality will only work with newer kernel > versions, but you should be able to run any version with any kernel > (within reason anyway) and make use of the core functionality. There > may be some exceptions here, but they should be detailed in the release > notes for specific versions. > > As for changing the md version in the kernel - it may be possible, but > generally there's a lot of work involved in back/forward porting code > between kernel versions (because of changes to core structures, etc). > > Is there any particular reason you're asking this (e.g. needing to use > some of the latest functionality with an older kernel)? You may get a > more definitive answer if you have a specific case. Thanks this info was very helpful. The reason I asked was because I have been following a thread re MD-XFS 50% write performance issue with different kernel releases and as performance is important to me I was thinking it might be better for me to use an older kernel (2.6.28.4) but keeping md,mdadm functionality up to date Ian.d > > HTH, > Robin > -- > ___ > ( ' } | Robin Hill <robin@xxxxxxxxxxxxxxx> | > / / ) | Little Jim says .... | > // !! | "He fallen in de water !!" | -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
