Advice on RAID

[Chris Mason]

I am setting up a server to store my photos and I wanted to make it a very
safe RAID. I selected 160 GB drives as the price is reasonable and put in
two dual interface Promise ATA cards. I set up 5 160 GB drives as 4 RAID
drives and one spare, the intention being it could lose a drive and still
have a redundant drive to use for parity:

[root at munster root]# cat /etc/raidtab 
raiddev /dev/md0
        raid-level      5
        nr-raid-disks   4
        nr-spare-disks  1
        persistent-superblock 1
        parity-algorithm        left-symmetric
        chunk-size      32
        device          /dev/hde1
        raid-disk       0
        device          /dev/hdg1
        raid-disk       1
        device          /dev/hdi1
        raid-disk       2
        device          /dev/hdk1
        raid-disk       3
        device          /dev/hdb1
        spare-disk      0


 When I run "cat /proc/mdstat " I get:

Personalities : [raid5] 
read_ahead 1024 sectors
md0 : active raid5 hdb1[4] hdk1[3] hdi1[2] hdg1[1] hde1[0]
      468864768 blocks level 5, 32k chunk, algorithm 2 [4/4] [UUUU]
      [=>...................]  resync =  7.8% (12315804/156288256)
finish=232.3min speed=10324K/sec
unused devices: <none>


Does this mean the array is using all 5 disks?


Here's the relevant section from dmesg

SiS651    ATA 133 controller
    ide0: BM-DMA at 0xa400-0xa407, BIOS settings: hda:DMA, hdb:DMA
    ide1: BM-DMA at 0xa408-0xa40f, BIOS settings: hdc:pio, hdd:pio
PDC20269: IDE controller at PCI slot 00:0e.0
PDC20269: chipset revision 2
PDC20269: not 100% native mode: will probe irqs later
    ide2: BM-DMA at 0x7000-0x7007, BIOS settings: hde:pio, hdf:pio
    ide3: BM-DMA at 0x7008-0x700f, BIOS settings: hdg:pio, hdh:pio
PDC20268: IDE controller at PCI slot 00:10.0
PDC20268: chipset revision 2
PDC20268: not 100% native mode: will probe irqs later
    ide4: BM-DMA at 0x5400-0x5407, BIOS settings: hdi:pio, hdj:pio
    ide5: BM-DMA at 0x5408-0x540f, BIOS settings: hdk:pio, hdl:pio
hda: Maxtor 2F040L0, ATA DISK drive
hdb: WDC WD1600BB-00HTA0, ATA DISK drive
blk: queue c03cdfe0, I/O limit 4095Mb (mask 0xffffffff)
blk: queue c03ce124, I/O limit 4095Mb (mask 0xffffffff)
hde: WDC WD1600JB-00EVA0, ATA DISK drive
blk: queue c03ce8a8, I/O limit 4095Mb (mask 0xffffffff)
hdg: WDC WD1600BB-00HTA0, ATA DISK drive
blk: queue c03ced0c, I/O limit 4095Mb (mask 0xffffffff)
hdi: WDC WD1600JB-00EVA0, ATA DISK drive
blk: queue c03cf170, I/O limit 4095Mb (mask 0xffffffff)
hdk: WDC WD1600JB-00EVA0, ATA DISK drive
blk: queue c03cf5d4, I/O limit 4095Mb (mask 0xffffffff)
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide2 at 0x8400-0x8407,0x8002 on irq 10
ide3 at 0x7800-0x7807,0x7402 on irq 10
ide4 at 0x6800-0x6807,0x6402 on irq 3
ide5 at 0x6000-0x6007,0x5802 on irq 3
hda: attached ide-disk driver.
hda: host protected area => 1
hda: 80293248 sectors (41110 MB) w/2048KiB Cache, CHS=4998/255/63, UDMA(133)
hdb: attached ide-disk driver.
hdb: host protected area => 1
hdb: 312581808 sectors (160042 MB) w/2048KiB Cache, CHS=19457/255/63,
UDMA(100)
hde: attached ide-disk driver.
hde: host protected area => 1
hde: 312581808 sectors (160042 MB) w/8192KiB Cache, CHS=19457/255/63,
UDMA(100)
hdg: attached ide-disk driver.
hdg: host protected area => 1
hdg: 312581808 sectors (160042 MB) w/2048KiB Cache, CHS=19457/255/63,
UDMA(100)
hdi: attached ide-disk driver.
hdi: host protected area => 1
hdi: 312581808 sectors (160042 MB) w/8192KiB Cache, CHS=19457/255/63,
UDMA(100)
hdk: attached ide-disk driver.
hdk: host protected area => 1
hdk: 312581808 sectors (160042 MB) w/8192KiB Cache, CHS=19457/255/63,
UDMA(100)
ide-floppy driver 0.99.newide
Partition check:
 hda: hda1 hda2 hda3
 hdb: hdb1
 hde: hde1
 hdg: hdg1
 hdi: hdi1
 hdk: hdk1
ide-floppy driver 0.99.newide
md: md driver 0.90.0 MAX_MD_DEVS=256, MD_SB_DISKS=27
md: Autodetecting RAID arrays.
 [events: 00000002]
 [events: 00000002]
 [events: 00000002]
 [events: 00000002]
 [events: 00000002]
md: autorun ...
md: considering hdk1 ...
md:  adding hdk1 ...
md:  adding hdi1 ...
md:  adding hdg1 ...
md:  adding hde1 ...
md:  adding hdb1 ...
md: created md0
md: bind<hdb1,1>
md: bind<hde1,2>
md: bind<hdg1,3>
md: bind<hdi1,4>
md: bind<hdk1,5>
md: running: <hdk1><hdi1><hdg1><hde1><hdb1>
md: hdk1's event counter: 00000002
md: hdi1's event counter: 00000002
md: hdg1's event counter: 00000002
md: hde1's event counter: 00000002
md: hdb1's event counter: 00000002
md: md0: raid array is not clean -- starting background reconstruction
kmod: failed to exec /sbin/modprobe -s -k md-personality-4, errno = 2
md: personality 4 is not loaded!
md :do_md_run() returned -22
md: md0 stopped.
md: unbind<hdk1,4>
md: export_rdev(hdk1)
md: unbind<hdi1,3>
md: export_rdev(hdi1)
md: unbind<hdg1,2>
md: export_rdev(hdg1)
md: unbind<hde1,1>
md: export_rdev(hde1)
md: unbind<hdb1,0>
md: export_rdev(hdb1)
md: ... autorun DONE.

Chris Mason