Slackware 10 Autodetects Software RAID ?!?!?!

SiegeX · 07-26-2004, 04:49 AM

I previously had Slackware 9.1 on my box running software RAID across three scsi drives. In particular I had a RAID1 array for '/boot' and a RAID5 array for '/' (note that I did not RAID the swap partitions.)

So today I decided now would be a good time to do a 'clean install' of Slackware 10.0. So I booted off the first ISO CD and ran 'scsi.s' To my surprise without me having to do anything at all, it somehow knew that I wanted to make a RAID1 and RAID5 array, and so it built them for me. All i needed to do was to format /dev/md0 and /dev/md1 in 'setup' and mount '/boot' to /dev/md0. I thought to myself, ok it must have noticed I had a previous install of Slackware already and it read my /etc/raidtab and used that, cool!

So then I go through the full install, reboot and cross my fingers and the Linux gods were kind to me because I was given a login prompt my first time. Out of curiosity I wanted to see what it did to create my raid arrays so I ran 'cat /etc/raidtab' and my jaw hit the floor when it said THERE IS NO RAIDTAB FILE!?!?!?

My best guess is that since my 3 disks were already partitioned to be exactly the same, it saw that as the marker to use raid. Then since I had 3 drives, it decided to make the lagest partion a RAID5 array and then since I mounted /dev/md0 to '/boot' it must have known to make it RAID1 since /boot cant live on a *software* RAID5.

If sombody knows exactly how this works, please tell us all and let me know what kernel options I need to get this RAID autodetection to work, especially for 2.6.7, because Ive always had to use the 'raidtab' file with my previous kernels and I thought I included all the stuff in the .config pertaining to RAID.

Ive included the output of 'dmesg' in case it is of any help. And while I have that, you'll notice that the kernel does some speed test on a few differnt RAID algorhythms and lists the throughput next to each. For some reason it decides to go with the 2nd higest throughput instead of the 1st, im wondering why this is so and if/how should I change this?

Code:

Linux version 2.4.26 (root@tree) (gcc version 3.3.4) #21 Mon Jun 14 19:17:44 PDT 2004
BIOS-provided physical RAM map:
 BIOS-e820: 0000000000000000 - 000000000009f800 (usable)
 BIOS-e820: 000000000009f800 - 00000000000a0000 (reserved)
 BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
 BIOS-e820: 0000000000100000 - 000000000fef0000 (usable)
 BIOS-e820: 000000000fef0000 - 000000000fef3000 (ACPI NVS)
 BIOS-e820: 000000000fef3000 - 000000000ff00000 (ACPI data)
 BIOS-e820: 00000000fec00000 - 00000000fec01000 (reserved)
 BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved)
 BIOS-e820: 00000000ffff0000 - 0000000100000000 (reserved)
254MB LOWMEM available.
On node 0 totalpages: 65264
zone(0): 4096 pages.
zone(1): 61168 pages.
zone(2): 0 pages.
Kernel command line: BOOT_IMAGE=Linux ro root=902
Initializing CPU#0
Detected 1624.702 MHz processor.
Console: colour dummy device 80x25
Calibrating delay loop... 3244.03 BogoMIPS
Memory: 254632k/261056k available (2013k kernel code, 6036k reserved, 757k data, 140k init, 0k highmem)
Dentry cache hash table entries: 32768 (order: 6, 262144 bytes)
Inode cache hash table entries: 16384 (order: 5, 131072 bytes)
Mount cache hash table entries: 512 (order: 0, 4096 bytes)
Buffer cache hash table entries: 16384 (order: 4, 65536 bytes)
Page-cache hash table entries: 65536 (order: 6, 262144 bytes)
CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line)
CPU: L2 Cache: 256K (64 bytes/line)
CPU:     After generic, caps: 0383fbff c1c3fbff 00000000 00000000
CPU:             Common caps: 0383fbff c1c3fbff 00000000 00000000
CPU: AMD Athlon(tm) XP 1900+ stepping 02
Enabling fast FPU save and restore... done.
Enabling unmasked SIMD FPU exception support... done.
Checking 'hlt' instruction... OK.
POSIX conformance testing by UNIFIX
mtrr: v1.40 (20010327) Richard Gooch (rgooch@atnf.csiro.au)
mtrr: detected mtrr type: Intel
PCI: PCI BIOS revision 2.10 entry at 0xfaf40, last bus=1
PCI: Using configuration type 1
PCI: Probing PCI hardware
PCI: Probing PCI hardware (bus 00)
PCI: Using IRQ router VIA [1106/3177] at 00:11.0
Linux NET4.0 for Linux 2.4
Based upon Swansea University Computer Society NET3.039
Initializing RT netlink socket
Starting kswapd
VFS: Disk quotas vdquot_6.5.1
Journalled Block Device driver loaded
vesafb: framebuffer at 0xd8000000, mapped to 0xd080d000, size 1536k
vesafb: mode is 1024x768x8, linelength=1024, pages=4
vesafb: protected mode interface info at c000:a410
vesafb: scrolling: redraw
Console: switching to colour frame buffer device 128x48
fb0: VESA VGA frame buffer device
pty: 512 Unix98 ptys configured
Serial driver version 5.05c (2001-07-08) with HUB-6 MANY_PORTS MULTIPORT SHARE_IRQ SERIAL_PCI enabled
ttyS00 at 0x03f8 (irq = 4) is a 16550A
Real Time Clock Driver v1.10f
Floppy drive(s): fd0 is 1.44M
FDC 0 is a post-1991 82077
RAMDISK driver initialized: 16 RAM disks of 7777K size 1024 blocksize
loop: loaded (max 8 devices)
Uniform Multi-Platform E-IDE driver Revision: 7.00beta4-2.4
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
VP_IDE: IDE controller at PCI slot 00:11.1
VP_IDE: chipset revision 6
VP_IDE: not 100% native mode: will probe irqs later
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
VP_IDE: VIA vt8235 (rev 00) IDE UDMA133 controller on pci00:11.1
    ide0: BM-DMA at 0xe400-0xe407, BIOS settings: hda:DMA, hdb:pio
    ide1: BM-DMA at 0xe408-0xe40f, BIOS settings: hdc:pio, hdd:pio
hda: ATAPI CDROM, ATAPI CD/DVD-ROM drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
hda: attached ide-cdrom driver.
hda: ATAPI 44X CD-ROM drive, 128kB Cache, UDMA(33)
Uniform CD-ROM driver Revision: 3.12
SCSI subsystem driver Revision: 1.00
PCI: Found IRQ 11 for device 00:09.0
PCI: Sharing IRQ 11 with 00:10.1
sym.0.9.0: setting PCI_COMMAND_PARITY...
sym.0.9.0: setting PCI_COMMAND_INVALIDATE.
sym0: <875> rev 0x26 on pci bus 0 device 9 function 0 irq 11
sym0: Tekram NVRAM, ID 7, Fast-20, SE, parity checking
sym0: SCSI BUS has been reset.
scsi0 : sym-2.1.17a
blk: queue cfe21274, I/O limit 4095Mb (mask 0xffffffff)
  Vendor: IBM       Model: DNES-309170W      Rev: SAH0
  Type:   Direct-Access                      ANSI SCSI revision: 03
blk: queue cfe21374, I/O limit 4095Mb (mask 0xffffffff)
  Vendor: IBM       Model: DNES-309170W      Rev: SA30
  Type:   Direct-Access                      ANSI SCSI revision: 03
blk: queue cfe21474, I/O limit 4095Mb (mask 0xffffffff)
  Vendor: IBM       Model: DNES-309170W      Rev: SAH0
  Type:   Direct-Access                      ANSI SCSI revision: 03
blk: queue cfe21574, I/O limit 4095Mb (mask 0xffffffff)
sym0:0:0: tagged command queuing enabled, command queue depth 16.
sym0:1:0: tagged command queuing enabled, command queue depth 16.
sym0:2:0: tagged command queuing enabled, command queue depth 16.
PCI: Found IRQ 11 for device 00:09.0
PCI: Sharing IRQ 11 with 00:10.1
Attached scsi disk sda at scsi0, channel 0, id 0, lun 0
Attached scsi disk sdb at scsi0, channel 0, id 1, lun 0
Attached scsi disk sdc at scsi0, channel 0, id 2, lun 0
sym0:0: FAST-20 WIDE SCSI 40.0 MB/s ST (50.0 ns, offset 16)
SCSI device sda: 17916240 512-byte hdwr sectors (9173 MB)
Partition check:
 sda: sda1 sda2 < sda5 sda6 >
sym0:1: FAST-20 WIDE SCSI 40.0 MB/s ST (50.0 ns, offset 16)
SCSI device sdb: 17916240 512-byte hdwr sectors (9173 MB)
 sdb: sdb1 sdb2 < sdb5 sdb6 >
sym0:2: FAST-20 WIDE SCSI 40.0 MB/s ST (50.0 ns, offset 16)
SCSI device sdc: 17916240 512-byte hdwr sectors (9173 MB)
 sdc: sdc1 sdc2 < sdc5 sdc6 >
md: linear personality registered as nr 1
md: raid0 personality registered as nr 2
md: raid1 personality registered as nr 3
md: raid5 personality registered as nr 4
raid5: measuring checksumming speed
   8regs     :  2328.400 MB/sec
   32regs    :  1560.000 MB/sec
   pIII_sse  :  4412.000 MB/sec
   pII_mmx   :  3802.000 MB/sec
   p5_mmx    :  4857.600 MB/sec
raid5: using function: pIII_sse (4412.000 MB/sec)
md: md driver 0.90.0 MAX_MD_DEVS=256, MD_SB_DISKS=27
md: Autodetecting RAID arrays.
 [events: 000007f5]
 [events: 002c144d]
 [events: 000007f5]
 [events: 002c144d]
 [events: 000007f5]
 [events: 002c144d]
md: autorun ...
md: considering sdc6 ...
md:  adding sdc6 ...
md:  adding sdb6 ...
md:  adding sda6 ...
md: created md2
md: bind<sda6,1>
md: bind<sdb6,2>
md: bind<sdc6,3>
md: running: <sdc6><sdb6><sda6>
md: sdc6's event counter: 002c144d
md: sdb6's event counter: 002c144d
md: sda6's event counter: 002c144d
md2: max total readahead window set to 512k
md2: 2 data-disks, max readahead per data-disk: 256k
raid5: device sdc6 operational as raid disk 2
raid5: device sdb6 operational as raid disk 1
raid5: device sda6 operational as raid disk 0
raid5: allocated 3284kB for md2
raid5: raid level 5 set md2 active with 3 out of 3 devices, algorithm 2
RAID5 conf printout:
 --- rd:3 wd:3 fd:0
 disk 0, s:0, o:1, n:0 rd:0 us:1 dev:sda6
 disk 1, s:0, o:1, n:1 rd:1 us:1 dev:sdb6
 disk 2, s:0, o:1, n:2 rd:2 us:1 dev:sdc6
RAID5 conf printout:
 --- rd:3 wd:3 fd:0
 disk 0, s:0, o:1, n:0 rd:0 us:1 dev:sda6
 disk 1, s:0, o:1, n:1 rd:1 us:1 dev:sdb6
 disk 2, s:0, o:1, n:2 rd:2 us:1 dev:sdc6
md: updating md2 RAID superblock on device
md: sdc6 [events: 002c144e]<6>(write) sdc6's sb offset: 8616832
md: sdb6 [events: 002c144e]<6>(write) sdb6's sb offset: 8616832
md: sda6 [events: 002c144e]<6>(write) sda6's sb offset: 8616832
md: considering sdc1 ...
md:  adding sdc1 ...
md:  adding sdb1 ...
md:  adding sda1 ...
md: created md0
md: bind<sda1,1>
md: bind<sdb1,2>
md: bind<sdc1,3>
md: running: <sdc1><sdb1><sda1>
md: sdc1's event counter: 000007f5
md: sdb1's event counter: 000007f5
md: sda1's event counter: 000007f5
md: RAID level 1 does not need chunksize! Continuing anyway.
md0: max total readahead window set to 124k
md0: 1 data-disks, max readahead per data-disk: 124k
raid1: device sdc1 operational as mirror 2
raid1: device sdb1 operational as mirror 1
raid1: device sda1 operational as mirror 0
raid1: raid set md0 active with 3 out of 3 mirrors
md: updating md0 RAID superblock on device
md: sdc1 [events: 000007f6]<6>(write) sdc1's sb offset: 97152
md: sdb1 [events: 000007f6]<6>(write) sdb1's sb offset: 97152
md: sda1 [events: 000007f6]<6>(write) sda1's sb offset: 97152
md: ... autorun DONE.
LVM version 1.0.8(17/11/2003)
Initializing Cryptographic API
NET4: Linux TCP/IP 1.0 for NET4.0
IP Protocols: ICMP, UDP, TCP, IGMP
IP: routing cache hash table of 2048 buckets, 16Kbytes
TCP: Hash tables configured (established 16384 bind 32768)
Linux IP multicast router 0.06 plus PIM-SM
NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
raid5: switching cache buffer size, 4096 --> 1024
raid5: switching cache buffer size, 1024 --> 512
FAT: bogus logical sector size 0
UMSDOS: msdos_read_super failed, mount aborted.
FAT: bogus logical sector size 0
FAT: bogus logical sector size 0
md: swapper(pid 1) used obsolete MD ioctl, upgrade your software to use new ictls.
raid5: switching cache buffer size, 512 --> 1024
raid5: switching cache buffer size, 1024 --> 4096
reiserfs: found format "3.6" with standard journal
reiserfs: checking transaction log (device md(9,2)) ...
for (md(9,2))
md(9,2):Using r5 hash to sort names
VFS: Mounted root (reiserfs filesystem) readonly.
Freeing unused kernel memory: 140k freed
Adding Swap: 243688k swap-space (priority -1)
Adding Swap: 243688k swap-space (priority -2)
Adding Swap: 243688k swap-space (priority -3)
md: fsck.reiserfs(pid 23) used obsolete MD ioctl, upgrade your software to use new ictls.
Linux agpgart interface v0.99 (c) Jeff Hartmann
agpgart: Maximum main memory to use for agp memory: 202M
agpgart: Detected Via Apollo Pro KT400 chipset
agpgart: unable to determine aperture size.
PCI: Found IRQ 5 for device 00:0b.0
PCI: Sharing IRQ 5 with 00:10.3
3c59x: Donald Becker and others. 
See Documentation/networking/vortex.txt
00:0b.0: 3Com PCI 3c905 Boomerang 100baseTx at 0xd400. Vers LK1.1.18-ac
 00:60:08:11:9d:86, IRQ 5
  product code 4b4b rev 00.0 date 05-31-97
  Internal config register is 16302d8, transceivers 0xe040.
  8K word-wide RAM 3:5 Rx:Tx split, autoselect/MII interface.
  MII transceiver found at address 24, status 786f.
  Enabling bus-master transmits and whole-frame receives.
00:0b.0: scatter/gather enabled. h/w checksums disabled
eth0: Dropping NETIF_F_SG since no checksum feature.
scsi1 : SCSI host adapter emulation for IDE ATAPI devices
md: fsck.reiserfs(pid 42) used obsolete MD ioctl, upgrade your software to use new ictls.
reiserfs: found format "3.6" with standard journal
reiserfs: checking transaction log (device md(9,0)) ...
for (md(9,0))
md(9,0):Using r5 hash to sort names
Linux Kernel Card Services 3.1.22
  options:  [pci] [cardbus] [pm]
isapnp: Scanning for PnP cards...
isapnp: No Plug & Play device found
Intel ISA PCIC probe: not found.
Databook TCIC-2 PCMCIA probe: not found.
ds: no socket drivers loaded!
via-rhine.c:v1.10-LK1.1.19  July-12-2003  Written by Donald Becker
PCI: Found IRQ 10 for device 00:12.0
PCI: Sharing IRQ 10 with 00:10.0
eth1: VIA VT6102 Rhine-II at 0xec00, 00:50:8d:52:b6:3c, IRQ 10.
eth1: MII PHY found at address 1, status 0x786d advertising 05e1 Link 45e1.
eth1: Setting full-duplex based on MII #1 link partner capability of 45e1.
via82xx: Assuming DXS channels with 48k fixed sample rate.
         Please try dxs_support=1 or dxs_support=4 option
         and report if it works on your machine.
PCI: Found IRQ 3 for device 00:11.5
PCI: Sharing IRQ 3 with 00:10.2
PCI: Setting latency timer of device 00:11.5 to 64
usb.c: registered new driver usbdevfs
usb.c: registered new driver hub
PCI: Found IRQ 5 for device 00:10.3
PCI: Sharing IRQ 5 with 00:0b.0
ehci_hcd 00:10.3: VIA Technologies, Inc. USB 2.0
ehci_hcd 00:10.3: irq 5, pci mem d0c3e000
usb.c: new USB bus registered, assigned bus number 1
ehci_hcd 00:10.3: USB 2.0 enabled, EHCI 1.00, driver 2003-Dec-29/2.4
hub.c: USB hub found
hub.c: 6 ports detected
uhci.c: USB Universal Host Controller Interface driver v1.1
PCI: Found IRQ 10 for device 00:10.0
PCI: Sharing IRQ 10 with 00:12.0
uhci.c: USB UHCI at I/O 0xd800, IRQ 10
usb.c: new USB bus registered, assigned bus number 2
hub.c: USB hub found
hub.c: 2 ports detected
PCI: Found IRQ 11 for device 00:10.1
PCI: Sharing IRQ 11 with 00:09.0
uhci.c: USB UHCI at I/O 0xdc00, IRQ 11
usb.c: new USB bus registered, assigned bus number 3
hub.c: USB hub found
hub.c: 2 ports detected
PCI: Found IRQ 3 for device 00:10.2
PCI: Sharing IRQ 3 with 00:11.5
uhci.c: USB UHCI at I/O 0xe000, IRQ 3
usb.c: new USB bus registered, assigned bus number 4
hub.c: USB hub found
hub.c: 2 ports detected

Andronik · 07-26-2004, 05:59 AM

yes it autotetects existing raidvolumes and starts them, because kernel supports it.

but it is not so smart to make initrd itself, at least on fresh install over existing mirrors.
so when i boot i have kernel panic, suggesting to add some init= options.
good question is how to do that raid-initrd under rescue cd.
cant find mkinitrd utility here.

maybe some hardware guru on software raids can help?

oops-seems that slack dont use initrd at all.
after some diggig i found this document helpful: http://slacksite.com/slackware/raid.html

SiegeX · 07-26-2004, 08:57 PM

thanks for the link, but even in that page you gave me, they use the /etc/raidtab file. How is it that my box is working without one???

gargamel · 07-27-2004, 05:26 PM

AFAIK the raidtab file is only used for the initial configuration of a RAID system, and when something goes wrong. Other than that the raidtab file has only documentary purpose, so that you can what your RAID looks like.
Not sure if I reproduced this correctly from memory. I suggest you take a look in the RAID-Howto at http://www.tldp.org, where I read the above a while ago.

gargamel