Topic: RIAD Newbie question

[Harald]

Hi all,

I'd like to setup a SME box with RAID-1 with 2 hds, one 10 GB, the other 25 GB, and use the last 15 GB on the latter one as an extra/2nd disk/partition.
I do have Partition Magic.

Question:
A: is it possible at all?
If so - B: Is this the right way to do this:
1. Do all the partitioning with PMagic before the installation, hiding the extra 15 GB partition.
2. Do an installation with RAID-1 on the 1st 10GB HD + the 10 GB partion on the 2nd HD.
3. After the installation unhide the 15 GB partition on the 2nd HD with PMagic and then mount it manually as second HD in SME Server (+ mounting it via fstab after finding out that it works OK) ?

Thanks for your help.

Harald

[Nathan Fowler]

No, RAID-1 will only allocate a partition the size of the smallest disk, using RAID-1 with a 25GB drive and a 10GB drive will yeild 10GB (100% utilization on disk1) and 10GB (40% utilization on disk2).  This should leave you 15GB of unpartitioned space which can be allocated from the console by running fdisk and creating a new partition.  The new partition won't be RAID-1 obviously, but you can still allocate that space for "non-critical" data.  I would stay away from Partition magic, as it is not necessary and could actually cause some headaches.

Hope this helped,
Nathan

[Kelly Marshall]

I am trying to set up a server with two 40GB Hard drives for RAID-1 Mirroring.  I go into the BIOS and set it up and then I start the SME-Server installation and it says that no hard drives are found.  If I start RedHat 7.3 installation it shows both hard drives.  Any suggestions as to why I am seeing this error message with SME-Server 5.5?

Thanks,

Kelly

[Harald]

Hello Nathan,

Late, but ... Thank you for your help.
I tried and tried, but it didn't work (probably the computer is too old, i.e the BIOS has problems with the disks and only recognises 8 GB).
So I gave up and installed in single disk mode (but with both disks connected, the smaller one in normal mode, the bigger one with CHS translation).
Now the server works (exept for internet access - but that's a different story and a different posting).
The dmesg-log tells me something about 'raid5' and apparently still both disks are used but I've no idea where to start to find out.
And even with the network cable disconnected there's constant disk activity.
But, as I said, the internal network works (server-manager and primary website accessable).

Any hints?

Thank you,
   Harald

[Nathan Fowler]

Raid information can be found by issuing the following command at console:
cat /proc/mdstat

[UU] means both disks are uniform.

[Harald]

Nathan wrote on 09-25-02 13:28:
Raid information can be found by issuing the following command at console:
cat /proc/mdstat
---
Output to that is:
read_ahead not set
unused devices:

In 'dmesg' log I found this:
...
PIIX4: IDE controller on PCI bus 00 dev 39
PIIX4: not 100% native mode: will probe irqs later
    ide0: BM-DMA at 0xfcf0-0xfcf7, BIOS settings: hda:pio, hdb:DMA
    ide1: BM-DMA at 0xfcf8-0xfcff, BIOS settings: hdc:DMA, hdd:pio
hda: ST310212A, ATA DISK drive     [is master on primary IDE contr.]
hdb: DC5-E6, ATAPI CDROM drive   [is slave on primary IDE contr.]
hdc: IC35L060AVER07-0, ATA DISK drive   [is master on secondary IDE contr.]
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide1 at 0x170-0x177,0x376 on irq 15
hda: ST310212A, 9768MB w/512kB Cache, CHS=19846/16/63
hdc: IC35L060AVER07-0, 58644MB w/1916kB Cache, CHS=7476/255/63
       [dirve is 60 GB, not 25 as I wrongly said in former posting]
Floppy drive(s): fd0 is 1.44M
FDC 0 is a National Semiconductor PC87306
md driver 0.90.0 MAX_MD_DEVS=256, MAX_REAL=12
raid5: measuring checksumming speed
raid5: MMX detected, trying high-speed MMX checksum routines
   pII_mmx   :   747.903 MB/sec
   p5_mmx    :   781.050 MB/sec
   8regs     :   573.786 MB/sec
   32regs    :   337.566 MB/sec
using fastest function: p5_mmx (781.050 MB/sec)
scsi : 0 hosts.
scsi : detected total.
md.c: sizeof(mdp_super_t) = 4096
Partition check:
 hda: hda1
 hdc: hdc1 hdc2
autodetecting RAID arrays
autorun ...
... autorun DONE.
apm: BIOS version 1.2 Flags 0x03 (Driver version 1.13)
VFS: Mounted root (ext2 filesystem) readonly.
Freeing unused kernel memory: 72k freed
Adding Swap: 265032k swap-space (priority -1)
...

Question:
- is this now running as a RAID-5?
- How can I find out what data is physically on the 1st drive and what on the second?
- Why is there constant disk activity - even when the machine is completely disconnected from any network?

Harald

[Nathan Fowler]

I think you're confusing the RAID levels.  RAID-1 is mirroring and is supported by E-Smith, other software RAID alternatives are supported but require a manual configuration.  To operate RAID-5 you need three physical disks, RAID-5 is RAID-0 with parity.  The three disks are required for parity, RAID-0 simply requires two disks but does not provide fault tolerance.  RAID-1 is mirroring.

If you have no entries in /proc/mdstat chances are you are not operating under RAID.  An example (from my system) of RAID-1 status from /proc/mdstat would be:

Personalities : [raid1]
read_ahead 1024 sectors
md2 : active raid1 hdc1[1] hda1[0] 264000 blocks [2/2] [UU]
md0 : active raid1 hdc5[1] hda5[0] 11968 blocks [2/2] [UU]
md1 : active raid1 hdc6[1] hda6[0] 975616 blocks [2/2] [UU]
unused devices:

I'm not sure why you're seeing constant disk activity, I'm also concerned that your 9GB drive is configured as CHS in the BIOS (if I remember you saying that).  My recommendation would be to perhaps attempt a re-install?

An example of dmesg reporting a RAID-1 bootup from my system can be seen below:
PIIX4: IDE controller on PCI bus 00 dev 39
PIIX4: not 100% native mode: will probe irqs later
ide0: BM-DMA at 0xf000-0xf007, BIOS settings: hda:pio, hdb:pio
ide1: BM-DMA at 0xf008-0xf00f, BIOS settings: hdc:pio, hdd:pio
hda: QUANTUM FIREBALL1280A, ATA DISK drive
hdc: QUANTUM FIREBALL1280A, ATA DISK drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide1 at 0x170-0x177,0x376 on irq 15
hda: QUANTUM FIREBALL1280A, 1222MB w/83kB Cache, CHS=621/64/63
hdc: QUANTUM FIREBALL1280A, 1222MB w/83kB Cache, CHS=2484/16/63
Floppy drive(s): fd0 is 1.44M
FDC 0 is a post-1991 82077
md driver 0.90.0 MAX_MD_DEVS=256, MAX_REAL=12
raid5: measuring checksumming speed
raid5: MMX detected, trying high-speed MMX checksum routines
pII_mmx : 743.331 MB/sec
p5_mmx : 780.669 MB/sec
8regs : 573.786 MB/sec
32regs : 321.564 MB/sec
using fastest function: p5_mmx (780.669 MB/sec)
scsi : 0 hosts.
scsi : detected total.
md.c: sizeof(mdp_super_t) = 4096
Partition check:
hda: hda1 hda2 < hda5 hda6 >
hdc: [PTBL] [621/64/63] hdc1 hdc2 < hdc5 hdc6 >
RAMDISK: Compressed image found at block 0
autodetecting RAID arrays
(read) hda1's sb offset: 264000 [events: 000000c4]
(read) hda5's sb offset: 11968 [events: 000000c1]
(read) hda6's sb offset: 975616 [events: 000000c1]
(read) hdc1's sb offset: 264000 [events: 000000c4]
(read) hdc5's sb offset: 11968 [events: 000000c1]
(read) hdc6's sb offset: 975616 [events: 000000c1]
autorun ...
considering hdc6 ...
adding hdc6 ...
adding hda6 ...
created md1
bind
bind
running:
now!
hdc6's event counter: 000000c1
hda6's event counter: 000000c1
request_module[md-personality-3]: Root fs not mounted
do_md_run() returned -22
unbind
export_rdev(hdc6)
unbind
export_rdev(hda6)
md1 stopped.
considering hdc5 ...
adding hdc5 ...
adding hda5 ...
created md0
bind
bind
running:
now!
hdc5's event counter: 000000c1
hda5's event counter: 000000c1
request_module[md-personality-3]: Root fs not mounted
do_md_run() returned -22
unbind
export_rdev(hdc5)
unbind
export_rdev(hda5)
md0 stopped.
considering hdc1 ...
adding hdc1 ...
adding hda1 ...
created md2
bind
bind
running:
now!
hdc1's event counter: 000000c4
hda1's event counter: 000000c4
request_module[md-personality-3]: Root fs not mounted
do_md_run() returned -22
unbind
export_rdev(hdc1)
unbind
export_rdev(hda1)
md2 stopped.
... autorun DONE.
EXT2-fs warning: checktime reached, running e2fsck is recommended
VFS: Mounted root (ext2 filesystem).
raid1 personality registered
autodetecting RAID arrays
(read) hda1's sb offset: 264000 [events: 000000c4]
(read) hda5's sb offset: 11968 [events: 000000c1]
(read) hda6's sb offset: 975616 [events: 000000c1]
(read) hdc1's sb offset: 264000 [events: 000000c4]
(read) hdc5's sb offset: 11968 [events: 000000c1]
(read) hdc6's sb offset: 975616 [events: 000000c1]
autorun ...
considering hdc6 ...
adding hdc6 ...
adding hda6 ...
created md1
bind
bind
running:
now!
hdc6's event counter: 000000c1
hda6's event counter: 000000c1
md1: max total readahead window set to 128k
md1: 1 data-disks, max readahead per data-disk: 128k
raid1: device hdc6 operational as mirror 1
raid1: device hda6 operational as mirror 0
(checking disk 0)
(really checking disk 0)
(checking disk 1)
(really checking disk 1)
(checking disk 2)
(checking disk 3)
(checking disk 4)
(checking disk 5)
(checking disk 6)
(checking disk 7)
(checking disk
(checking disk 9)
(checking disk 10)
(checking disk 11)
raid1: raid set md1 active with 2 out of 2 mirrors
md: updating md1 RAID superblock on device
hdc6 [events: 000000c2](write) hdc6's sb offset: 975616
hda6 [events: 000000c2](write) hda6's sb offset: 975616
.
considering hdc5 ...
adding hdc5 ...
adding hda5 ...
created md0
bind
bind
running:
now!
hdc5's event counter: 000000c1
hda5's event counter: 000000c1
md0: max total readahead window set to 128k
md0: 1 data-disks, max readahead per data-disk: 128k
raid1: device hdc5 operational as mirror 1
raid1: device hda5 operational as mirror 0
(checking disk 0)
(really checking disk 0)
(checking disk 1)
(really checking disk 1)
(checking disk 2)
(checking disk 3)
(checking disk 4)
(checking disk 5)
(checking disk 6)
(checking disk 7)
(checking disk
(checking disk 9)
(checking disk 10)
(checking disk 11)
raid1: raid set md0 active with 2 out of 2 mirrors
md: updating md0 RAID superblock on device
hdc5 [events: 000000c2](write) hdc5's sb offset: 11968
hda5 [events: 000000c2](write) hda5's sb offset: 11968
.
considering hdc1 ...
adding hdc1 ...
adding hda1 ...
created md2
bind
bind
running:
now!
hdc1's event counter: 000000c4
hda1's event counter: 000000c4
md2: max total readahead window set to 128k
md2: 1 data-disks, max readahead per data-disk: 128k
raid1: device hdc1 operational as mirror 1
raid1: device hda1 operational as mirror 0
(checking disk 0)
(really checking disk 0)
(checking disk 1)
(really checking disk 1)
(checking disk 2)
(checking disk 3)
(checking disk 4)
(checking disk 5)
(checking disk 6)
(checking disk 7)
(checking disk
(checking disk 9)
(checking disk 10)
(checking disk 11)
raid1: raid set md2 active with 2 out of 2 mirrors
md: updating md2 RAID superblock on device
hdc1 [events: 000000c5](write) hdc1's sb offset: 264000
hda1 [events: 000000c5](write) hda1's sb offset: 264000
.
... autorun DONE.
VFS: Mounted root (ext2 filesystem) readonly.
change_root: old root has d_count=1
Trying to unmount old root ... okay
Freeing unused kernel memory: 64k freed
Init module