} -----Original Message----- } From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid- } owner@xxxxxxxxxxxxxxx] On Behalf Of Ming Zhang } Sent: Tuesday, April 11, 2006 6:13 PM } To: Andy Smith } Cc: linux-raid@xxxxxxxxxxxxxxx } Subject: Re: mdadm + raid1 of 2 disks and now need to add more } } On Tue, 2006-04-11 at 20:32 +0000, Andy Smith wrote: } > On Tue, Apr 11, 2006 at 07:25:58PM +0200, Laurent CARON wrote: } > > Andy Smith wrote: } > > >On Tue, Apr 11, 2006 at 04:41:30PM +0200, Shai wrote: } > > >>I have two SCSI disks on raid1. } > > >>Since I have lots of reads from that raid, I want to add two more } > > >>disks to this raid so that read will be faster. } > > >> } > > >>How should I add the new disks? } > > > } > > >Is this possible with md currently: } > > > } > > >Create a RAID-10 on the two new disks specifying one disk missing } > > >from each mirror. } > > > } > > >Then copy data over and add the two existing disks letting it } > > >resync? } > > } > > Why not growing the array with 2 more disks? } > } > Well I guess a RAID-1 of 4 disks would be slightly more redundant } > than a 4 disk RAID-10, but it would have half the capacity, and the } > read performance would be very similar, no? } } raid1 of 4 will give u read performance like 1 disk; } raid10 of 4 can give u read performance like aggregated 2 disks. I know RAID1 of 4 disks will give you read performance like 4 disks. Unless your test or application is single threaded! Not likely I hope! At least with the 2.4.31 kernel. A RAID1 of 4 disks will still function with any 3 failed disks. Real good idea for remote systems. Also I think raid10 of 4 can give u read performance like 2 to 4 disks. This depends more on the application. IMO. You would have twice the space, but maybe not needed. } } } > } } - } 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
