Need to remove failed disk from RAID5 array

[Alex <mysqlstudent@gmail.com>]

Hi,

I have a degraded RAID5 array on an fc15 box due to sda failing:

Personalities : [raid6] [raid5] [raid4]
md1 : active raid5 sda3[5](F) sdd2[4] sdc2[2] sdb2[1]
      2890747392 blocks super 1.1 level 5, 512k chunk, algorithm 2 [4/3] [_UUU]
      bitmap: 8/8 pages [32KB], 65536KB chunk

md0 : active raid5 sda2[5] sdd1[4] sdc1[2] sdb1[1]
      30715392 blocks super 1.1 level 5, 512k chunk, algorithm 2 [4/4] [UUUU]
      bitmap: 0/1 pages [0KB], 65536KB chunk

There's a ton of messages like these:

end_request: I/O error, dev sda, sector 1668467332
md/raid:md1: read error NOT corrected!! (sector 1646961280 on sda3).
md/raid:md1: Disk failure on sda3, disabling device.
md/raid:md1: Operation continuing on 3 devices.
md/raid:md1: read error not correctable (sector 1646961288 on sda3).

What is the proper procedure to remove the disk from the array,
shutdown the server, and reboot with a new sda?

# mdadm --version
mdadm - v3.2.5 - 18th May 2012

# mdadm -Es
ARRAY /dev/md/0 metadata=1.1 UUID=4b5a3704:c681f663:99e744e4:254ebe3e
name=pixie.example.com:0
ARRAY /dev/md/1 metadata=1.1 UUID=d5032866:15381f0b:e725e8ae:26f9a971
name=pixie.example.com:1

# mdadm --detail /dev/md1
/dev/md1:
        Version : 1.1
  Creation Time : Sun Aug  7 12:52:18 2011
     Raid Level : raid5
     Array Size : 2890747392 (2756.83 GiB 2960.13 GB)
  Used Dev Size : 963582464 (918.94 GiB 986.71 GB)
   Raid Devices : 4
  Total Devices : 4
    Persistence : Superblock is persistent

  Intent Bitmap : Internal

    Update Time : Mon Jul 16 19:14:11 2012
          State : active, degraded
 Active Devices : 3
Working Devices : 3
 Failed Devices : 1
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 512K

           Name : pixie.example.com:1  (local to host pixie.example.com)
           UUID : d5032866:15381f0b:e725e8ae:26f9a971
         Events : 162567

    Number   Major   Minor   RaidDevice State
       0       0        0        0      removed
       1       8       18        1      active sync   /dev/sdb2
       2       8       34        2      active sync   /dev/sdc2
       4       8       50        3      active sync   /dev/sdd2

       5       8        3        -      faulty spare   /dev/sda3

I'd appreciate a pointer to any existing documentation, or some
general guidance on the proper procedure.

Thanks,
Alex