On Sat, 2009-05-30 at 14:35 +0100, John Robinson wrote: > On 30/05/2009 06:44, SandeepKsinha wrote: > > Hi all, > > > > Say If I have a RAID 5 array of 50GB of five disks of 10GB each. > > > > I have data of 5GB. When a disk fails and replaced with a spare disk. > > Will the reconstruction happen only for the 5GB allocated disk blocks > > or it will happen for the whole disk size. > > The whole disc size, for now anyway; md does not currently note which > blocks have been used by its client (the filesystem, LVM, whatever). > > > Is it possible to make reconstruction intelligent enough to keep it optimized ? > > This has been discussed in combination with supporting SSD drives' TRIM > function, and would mean md had to keep track of used chunks or possibly > even sectors using a bitmap or something like that, but whether anyone's > working on it I don't know. I would say it should be possible to 'query' the filesystem for that information. Obviously this will only work if you run a filesystem on it which supports it, but it would seem like a nicer solution than a bitmap for it. > > Cheers, > > John. > > -- > 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 -- 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
