Re: how do I boot to a text console in 12.2?

classic Classic list List threaded Threaded
17 messages Options
Reply | Threaded
Open this post in threaded view
|

Re: how do I boot to a text console in 12.2?

L A Walsh
Felix Miata wrote:
> 2-Kernel/initrd changes require "running" lilo before a reboot can use
> them.
----
    This is because lilo a lilo booted kernel doesn't need
to know the FS format before booting --- it reads the boot code from the disk
sectors.  This is the most efficient type of boot though it can have problems.

    I always run a lilo as part of my install new kernel script, so it
was never an issue.

    Grub needs to know how to read a file system -- and how to read those
file sectors off disk.  It screwed that up so badly, that Suse stopped
supporting XFS because grub doing direct disk read/writes on a live file
  system wasn' supported.

    I was told that was fixed, but XFS support at SuSE never recovered to
where it was.





    Now SuSE doesn't support TEXT MODE booting, because it's not in GRUB?

    HEY LYNN, it still works in LILO!
    I remember that breaking in Grub when I first tried switching to grub
because grub uses a graphical boot instead of BIOS VGA chip modes...



> 3-Grub shell allows to manually boot from the Grub shell, crucially
> handy if menu.lst is missing or otherwise problematic.
---
    Can you use grub to boot directly from the hard disk, or do you
need a ram disk to pre-boot from in order to really boot from your hard
disk?


>
> 4-Interactive editing of initrd & kernel cmdline.
> 5-Chainloads NTLDR, IBM BM (at least in theory), other Grubs, & even Lilo.
---
lilo allows both of those



>
> 6-Easily configurable & installable even though booted to another OS or
> media.
> 7-Needs no files in /etc to be able to function or configure.
---
        You mean the "System Config dir?"... why would having config
dirs in the system config dir be a bad thing?

And so far, I've never had problems with video... well... sorta scratch...
when I boot from memory (kexec), but that doesn't count -- it's not using
lilo then..

        Hey, I would love to use grub if it worked...but last time I
tried it -- it turned off the video during boot and I couldn't see
the bootup....

That's probably what the OP wants too!... grub isn't giving her one of the
builtin VGA or EVGA console modes....



--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: how do I boot to a text console in 12.2?

Philipp Thomas-3
On Tue, 07 Aug 2012 17:41:15 -0700, Linda Walsh <[hidden email]>
wrote:

>It screwed that up so badly, that Suse stopped supporting XFS because
>grub doing direct disk read/writes on a live file system wasn' supported.

When should that have been? And if that ever happened, it must have
been looong ago because AFAIR we always supported XFS.

>  Now SuSE doesn't support TEXT MODE booting, because it's not in GRUB?

That's plain BS. Grub has nothing to do with the boot mode.
> Hey, I would love to use grub if it worked...but last time I
>tried it -- it turned off the video during boot and I couldn't see
>the bootup....

Again, *which* version of grub? Grub 2 needs a different approach to
have a graphical boot screen, but that has *nothing* to do with the
mode the kernel boots in.

Philipp
--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: how do I boot to a text console in 12.2?

Felix Miata-3
In reply to this post by L A Walsh
On 2012/08/07 17:41 (GMT-0700) Linda Walsh composed:

> Felix Miata wrote:

>      Now SuSE doesn't support TEXT MODE booting, because it's not in GRUB?
...
>      I remember that breaking in Grub when I first tried switching to grub
> because grub uses a graphical boot instead of BIOS VGA chip modes...

Is this is referring to GFXboot? You don't have to use it if you don't like
it. Just uninstall it. And, you can ESC from it any time if plain text you
want. If you're referring to what happens after making your Grub menu choice,
it's all about what's on cmdline. In openSUSE I keep splashy and bootsplash
uninstalled and locked out, plus 3, splash=verbose and vga=### and/or
video=####X### on most of my cmdlines to ensure against accidental
appearances of anything except text until after init has completed.

>>  3-Grub shell allows to manually boot from the Grub shell, crucially
>>  handy if menu.lst is missing or otherwise problematic.

>      Can you use grub to boot directly from the hard disk, or do you
> need a ram disk to pre-boot from in order to really boot from your hard
> disk?

AFAIK I have no RAM disks involved with normal booting of any of my systems,
unless an installation script is sneaking a temporary one into an initrd.

>>  4-Interactive editing of initrd&  kernel cmdline.
>>  5-Chainloads NTLDR, IBM BM (at least in theory), other Grubs,&  even Lilo.

> lilo allows both of those

I don't remember ever typing help at a Lilo prompt and getting anything
resembling a helpful response.

Also I don't think Lilo allows the more elementary rendition of #4. Grub
Legacy needs no menu. Once "installed" somewhere the MBR code can find, one
can boot directly to a Grub prompt, from which one can locate stage1s,
device.maps, kernels and initrds among other things, then boot by typing Grub
commands in the same manner one uses common command shells like bash.

>>  6-Easily configurable&  installable even though booted to another OS or  media.
>>  7-Needs no files in /etc to be able to function or configure.

> You mean the "System Config dir?"... why would having config
> dirs in the system config dir be a bad thing?

Only an overly complex bootloader like Grub2 needs to scatter the files
required to make it work or get it configured to work in multiple directory
trees. I can copy a tiny bundle of Grub Legacy files into one grub directory,
"install" it to a bootsector by typing as little as two short lines, then
initialize an operating system boot using without doing anything more before
seeing a Grub prompt or menu.

> And so far, I've never had problems with video... well... sorta scratch...
> when I boot from memory (kexec), but that doesn't count -- it's not using
> lilo then..

> Hey, I would love to use grub if it worked...but last time I
> tried it -- it turned off the video during boot and I couldn't see
> the bootup....

Grub Legacy couldn't have been responsible for that. Something put something
on cmdline, or something got left out of or misconfigured in the kernel or
initrd to cause that. Grub loads a kernel, and usually an initrd, plus feeds
some parameters to the kernel, same as Lilo does. What the kernel does with
what it's given isn't something Grub or Lilo have any control over, not Grub
Legacy anyway.

Grub is another story. 2.0 is barely out, and should be called something else
1.0, as it was for all practical purposes a complete redesign, akin to the
change from KDE3 to KDE4. Bugs and incomplete documentation are to be
expected from anything so immature.
--
"The wise are known for their understanding, and pleasant
words are persuasive." Proverbs 16:21 (New Living Translation)

  Team OS/2 ** Reg. Linux User #211409 ** a11y rocks!

Felix Miata  ***  http://fm.no-ip.com/
--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: how do I boot to a text console in 12.2?

Carlos E. R.-2
In reply to this post by L A Walsh
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 2012-08-08 02:41, Linda Walsh wrote:

> Grub needs to know how to read a file system -- and how to read those file sectors off disk.
> It screwed that up so badly, that Suse stopped supporting XFS because grub doing direct disk
> read/writes on a live file system wasn' supported.
>
> I was told that was fixed, but XFS support at SuSE never recovered to where it was.

This is simply FALSE.

openSUSE has always supported XFS.

What was broken was installing grub to an XFS partition, which is very different than what you said.
And it was not the fault of openSUSE, it was an upstream issue that has been solved.


- --
Cheers / Saludos,

                Carlos E. R.
                (from 12.1 "Asparagus" GM (bombadillo))
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.18 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iEYEARECAAYFAlAi6p4ACgkQU92UU+smfQX8bwCfRkKoeyHEwR4LeSREjvFjcBR3
dvQAni94ofbG6XB3+jQK0m/tk4DgEKng
=KCBo
-----END PGP SIGNATURE-----
--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: how do I boot to a text console in 12.2?

L A Walsh
Carlos E. R. wrote:

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> On 2012-08-08 02:41, Linda Walsh wrote:
>
>> Grub needs to know how to read a file system -- and how to read those file sectors off disk.
>> It screwed that up so badly, that Suse stopped supporting XFS because grub doing direct disk
>> read/writes on a live file system wasn' supported.
>>
>> I was told that was fixed, but XFS support at SuSE never recovered to where it was.
>
> This is simply FALSE.
>
> openSUSE has always supported XFS.
>
> What was broken was installing grub to an XFS partition, which is very different than what you said.
> And it was not the fault of openSUSE, it was an upstream issue that has been solved.
----
        To be clear... What wasn't supported is having an XFS-only based system --
because GRUB was the only loaded supported at one pointed.

        So the implication if you can't install grub->XFS is you can't install an XFS-only
based system.

        Second...as far as fault -- it was SuSE's fault because they chose to use grub
over LILO in that release, which did not have the problem.  They specifically
dropped support
for Lilo in that release, -- which I guess has been rescinded, but lilo is still
ill supported.

references:
http://forums.opensuse.org/english/get-technical-help-here/install-boot-login/403400-xfs-support-gone-boot-partition.html
http://opensuse.14.n6.nabble.com/grub-no-longer-being-maintained-drops-support-for-XFS-td3255047.html
http://www.mentby.com/Group/opensuse/grub-no-longer-being-maintained-so-suse-drops-support-for-xfs-boot.html

--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: how do I boot to a text console in 12.2?

Philipp Thomas-3
On Wed, 15 Aug 2012 10:58:48 -0700, Linda Walsh <[hidden email]>
wrote:

> To be clear... What wasn't supported is having an XFS-only based system --
>because GRUB was the only loaded supported at one pointed.

Yes, like booting from software raid or booting from lvm, both still
requiring a separate boot partition.

> So the implication if you can't install grub->XFS is you can't install an XFS-only
>based system.

So can't also install a lvm only system or a sw RAID one. So what?

> Second...as far as fault -- it was SuSE's fault because they chose to use grub
>over LILO in that release, which did not have the problem.

LILO has other problems, the least one being that you have to rerun
LILO after a kernel update.

Philipp
--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: how do I boot to a text console in 12.2?

L A Walsh
Philipp Thomas wrote:
> On Wed, 15 Aug 2012 10:58:48 -0700, Linda Walsh <[hidden email]>
> wrote:
>
>> To be clear... What wasn't supported is having an XFS-only based system --
>> because GRUB was the only loaded supported at one pointed.
>
> Yes, like booting from software raid or booting from lvm, both still
> requiring a separate boot partition.
----
        Um... are you trying you boot from a separate partition to a RAID
or LVM based system and no file system is involved after boot?

        Cuz as near as I can tell, you are trolling.  You need a file
system to boot from.  That's always going to be the case.  XFS is a file
system -- not a volume manager.   but if you want an lvm+SW raid system
You could do it with LILO if your SW RAID is on top of lvm (not sure
about linux-SW RAID... as it would have to have enough contiguous space on
1 device to read in the kernel.   I do know it works with a BIOS-SW RAID as
the first device though...

If you want to go the boot from lvm route, just
create as many partitions at the front of your disk with lvm as you
want alternate boots from, and LILO could boot from them.   I strongly
doubt Grub/Grub2 could -- then partition the rest of your disk as SW
RAID.  Maybe 32M partitions x 10 320MB at the beginning of each
disk only used on volumne0 -- to load the kernel from -- would probably still
need a RAMDISK to load udev and setup a dev device -- that could be stored in a
2nd partition -- in each case, lilo could map the HW sectors to the boot
map and work.

So is that really what you want?  Doesn't sound very flexibile.




--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: how do I boot to a text console in 12.2?

Philipp Thomas-3
On Wed, 15 Aug 2012 21:39:08 -0700, Linda Walsh <[hidden email]>
wrote:

> Um... are you trying you boot from a separate partition to a RAID
>or LVM based system and no file system is involved after boot?

Of cause a file system is involved after boot. On my work system it's
lvm for the the disk management and xfs as file system for all
partitions.

> Cuz as near as I can tell, you are trolling.

Didn't you notice that I wrote "sw raid OR lvm"? nowhere did I say
raid and lvm.

>You need a file system to boot from.

Of cause you do and I never denied it. But booting from lvm requires a
separate boot partition as does booting from from a sw raid (be it
pure sw or a fake raid (aka BIOS which also uses sw raid, just the
setup is done by bios) other than RAID 1 .i.e. mirroring, independent
of the boot loader you use.

>You could do it with LILO if your SW RAID is on top of lvm (not sure
>about linux-SW RAID... as it would have to have enough contiguous space on
>1 device to read in the kernel.   I do know it works with a BIOS-SW RAID as
>the first device though...

With anything besides RAID 1 it does not work reliably butr only by
chance.

>create as many partitions at the front of your disk with lvm as you
>want alternate boots from, and LILO could boot from them.

That would be a too fragile setup and no reason for me to use LILO.
I use grub and have come to like the added flexibility grub gives me
and I have no problem with an extra ext2 boot partition.

Philipp
--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: how do I boot to a text console in 12.2?

L A Walsh
Philipp Thomas wrote:

> On Wed, 15 Aug 2012 21:39:08 -0700, Linda Walsh <[hidden email]>
> wrote:
>
>> Um... are you trying you boot from a separate partition to a RAID
>> or LVM based system and no file system is involved after boot?
>
> Of cause a file system is involved after boot. On my work system it's
> lvm for the the disk management and xfs as file system for all
> partitions.
>
>> Cuz as near as I can tell, you are trolling.
>
> Didn't you notice that I wrote "sw raid OR lvm"? nowhere did I say
> raid and lvm.
----
        Oh -- you meant linux-based sw-raid.   SW-raids are included in
many Dell BIOS's, no-hardware is involved -- just SW -- and they work fine
to boot off of.

        Of course, if your driver to run the RAID is IN a RAID partition that
is only supported by the driver, you have a catch-22.

        But the same isn't true for booting with dm and lilo, since
lilo just uses 'disk space' independent of a file-system.

        So it could boot from a dm-only system (no file system), which is
what you seemed to think wasn't supported in lilo.

        So IF you have a file system like ext2 -- you can have an ext2-only
based system, if you want, isn't that true?  In fact, are their any file systems
supported as 'linux file systems' (i.e. they have to be able to hold user/group
permissions
all the standard stuff). That you can't boot from and use exclusively as your
file system?

        LVM and linux SW RAID are both virtual disk->physical-disk mapping programs.
LVM can do RAID 0 and 1 but it's prime purpose was to manage 'volumes' as
heterogeneous
collections of physical devices  that can be broken into arbitrary size, whereas
LSRaid takes multiple homogeneous devices and maps them into 1 virtual disk
(that is mirrored or
interleaved, or whatever, depending on what RAID level is used).  They are
optimized for
different use cases, but are still both ways of combining multiple physical devices
into 'featured' virtual volumes.

        Lilo might have problems booting directly from a DM LV, if the LV wasn't
all on the same device.  Could grub boot without a file system?  you can answer
that
you don't need that -- but you say you are going to use a file system.  There is
no requirement to use a separate, 'limited feature' file system to boot from in
lilo, whereas at one point, grub wasn't able to support a boot & root on an advanced
file system.   It's rather like telling me that I need a FAT32 filesystem to boot
from then I can boot to my real-file system.  Doesn't that sound a bit
ridiculous and
unreasonable?

        How is that different in requiring ext2 in order to run an xfs-only system?

        My point (as indirectly as I expressed it) was that linux has no restrictions
about what file system it boots from.  Lilo supports that feature.  Grub, at one
point,
did not (don't know about now).  The fact that Grub didn't support the full linux
file-system model should have been enough reason, alone to keep lilo an equally
supported choice as grub, as it provides features that Grub does no (and note --
I am not suggesting it be an exclusive choice, but as near as I can tell, it can
support
booting from anything Grub can, but the reverse was (and may still be) NOT true.

        Saying you can't boot from a from a volume manager that needs OS support to
properly emulate the virtual disk, is a reasonable constraint.  But file systems
have no such abilities -- they can only run in one partition (though it can be
physically
split -- that's done outside of the file system by other SW).  The only
requirement is
I am asserting lilo needs is to have the kernel image on the same disk (NOTE: it may
very well be able to boot from a RAID mapped device, but I haven't researched that,
so I'm not claiming that).  With or without a file system, lilo can start a kernel
from a single disk image.  However, Grub needs 'fullish' file system support, as
it provides pre-boot access to the file systems - so it has higher requirements.

        To use something that is limited at the start should have been sufficient to
keep a full-support bootloader in the primary-boot-loader group.   It wasn't.  As
a result, XFS was tossed aside -- and many people still don't boot from XFS even
though
they use XFS for their other partitions.

That's a black eye for Grub, that will only be recovered from when people stop
using a separate filesystem for what would otherwise be an XFS-only system.

  But I *think* it is history now, and if I understand people correctly,
XFS is fully supported as a boot file system (is that correct?)... so at this
point it's
only a historical event that can be learned from for those that remain open to
learning.

        To those that don't, any mention of the topic, no doubt sounds like a
grating noise.

--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: how do I boot to a text console in 12.2?

Philipp Thomas
* Linda Walsh ([hidden email]) [20120823 03:26]:

> Oh -- you meant linux-based sw-raid.   SW-raids are included in
> many Dell BIOS's, no-hardware is involved -- just SW -- and they work fine
> to boot off of.

That's what is normally called fakeRAID as the BIOS only sets up the RAID
drives and everything else is done by software.  And it *only* works
reliably with Grub when doing RAID1 i.e.  mirroring.  Grub can't boot
reliably from striping sw-raids as it has no driver for that.

Philipp
--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: how do I boot to a text console in 12.2?

Dave Howorth
Philipp Thomas wrote:

> * Linda Walsh ([hidden email]) [20120823 03:26]:
>
>> Oh -- you meant linux-based sw-raid.   SW-raids are included in
>> many Dell BIOS's, no-hardware is involved -- just SW -- and they work fine
>> to boot off of.
>
> That's what is normally called fakeRAID as the BIOS only sets up the RAID
> drives and everything else is done by software.  And it *only* works
> reliably with Grub when doing RAID1 i.e.  mirroring.  Grub can't boot
> reliably from striping sw-raids as it has no driver for that.

Just for clarity, there are two different RAID implementations to
consider here.

"linux-based sw-raid" would normally be taken to mean RAID implemented
by linux and using the mdadm program and friends, with device names like
/dev/md*.

BIOS-based fakeraid is different.
--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: how do I boot to a text console in 12.2?

L A Walsh
Dave Howorth wrote:

> Philipp Thomas wrote:
>> * Linda Walsh ([hidden email]) [20120823 03:26]:
>>
>>> Oh -- you meant linux-based sw-raid.   SW-raids are included in
>>> many Dell BIOS's, no-hardware is involved -- just SW -- and they work fine
>>> to boot off of.
>> That's what is normally called fakeRAID as the BIOS only sets up the RAID
>> drives and everything else is done by software.  And it *only* works
>> reliably with Grub when doing RAID1 i.e.  mirroring.  Grub can't boot
>> reliably from striping sw-raids as it has no driver for that.
----
        Holy poop, you are kidding?   Lilo has no special support for booting
from them either -- it sees them as 1 single SDA1 device as presented by the BIOS.

        Windows boots from them fine as well... I find it hard to believe grub
woudln't.  It looks like 1 HD to the OS -- Vs. on my HW based RAID that's also
booted
from the ROM (different sys), the OS (linux) CAN tell there are underlying disks
after
it boots up.

        I'd love to talk about what crap GRUB is for not being able to boot
on something so common, but I'm 90% certain it does.  It IS a type of LSI based
RAID -- just no HW support, but i'd guess LSI put in enough HW to at least
fool an OS to make it look like 1 disk -- only supports RAID0,1 or 0+1 (or is
that 1+0?)...
But it's their default disk device if you don't buy a raid card.


>
> Just for clarity, there are two different RAID implementations to
> consider here.
>
> "linux-based sw-raid" would normally be taken to mean RAID implemented
> by linux and using the mdadm program and friends, with device names like
> /dev/md*.
>
> BIOS-based fakeraid is different.
---
        Nothing fake about it for what it does.  It interleaves 4 150MB/s
SAS drives to yield up to 600MB/s just fine -- it doesn't do RAID5 or 6 like
HW RAID cards do, but for RAID1/RAID0, SW can do that fairly easily and efficiently.

        I'm more likely to think of SW RAID5 as 'fakeraid', given it's performance,
but that's just some sorta 'put-down' or 'one-upmanship that I wouldn't even think
of if you hadn't used the term.




--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: how do I boot to a text console in 12.2?

Philipp Thomas-3
On Sat, 25 Aug 2012 03:50:33 -0700, Linda Walsh <[hidden email]>
wrote:

> Holy poop, you are kidding?   Lilo has no special support for booting
>from them either -- it sees them as 1 single SDA1 device as presented by the BIOS.

Lilo sees a BIOS device, that's all. The kernel that boots later does
see more than one device. Want proof? Boot a rescue system that
doesn't load the dmraid stuff and presto, you'll see the separate
drives that constitute the RAID array. That's what distinguishes
software from hardware RAID: in hw raid the systems only see the RAID
drives you defined, nothing else.

In a BIOS or an md RAID booting directly from RAID with either LILO or
grub is only reliable when its a raid 1, i.e. when mirroring as it
doesn't matter which drive the boot loader accesses. When you have a
striping raid like raid 0 it's pure luck if booting succeeds.

Philipp
--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

difference between HW&SW RAIDS as they pertain to / affect booting (et al)

L A Walsh
Philipp Thomas wrote:
> On Sat, 25 Aug 2012 03:50:33 -0700, Linda Walsh <[hidden email]>
> wrote:
>
>> Holy poop, you are kidding?   Lilo has no special support for booting
>>from them either -- it sees them as 1 single SDA1 device as presented by the BIOS.
>
> Lilo sees a BIOS device, that's all. The kernel that boots later does
> see more than one device.
----

        I think we are experiencing different HW/SW.

        I see the exact opposite of what you describe.  With the dell
'virtual disk' SCSI disk device under a "SAS 6iR integrated workstation
controller, there is nothing visible from any piece of HW that shows me
the individual parts -- it IS on windows (but when I had an older machine
with similar HW running linux, it saw it as 1 disk as well with no way to
query individual disk stati or even see how many.

        My linux box runs with 2 HW raid controllers -- a dell
Perc i/6 card (kernel sees 1078) and an LSI 9280DE-8e which kernel
sees with a 2108 driver -- which is a bit odd, since the 2108, I think
is the 6Mb line, and I think my card is only 3Mb... probably same driver
though as the cards are the same family.

        Anyway.. In the HW setup, I set much more introspection into
what's there than with the SW setup.  Under /sys/devices/<bus> -- I see
the SLOTS (enclosures) that each disk is plugged into (not sure what
benefit this is yet ... but I can see 8 enclosures for the internal
HD controller -- and under each enclosure I can see
/sys/devices/pci0000:00/0000:00:0a.0/0000:02:00.0/host1/target1:0:32/1:0:32:0/enclosure/1:0:32:0/0:
active           : 0
fault            : 0
locate           : 0
status           : OK
type             : array device

/sys/devices/pci0000:00/0000:00:0a.0/0000:02:00.0/host1/target1:0:32/1:0:32:0/enclosure/1:0:32:0/0/power:
async            : disabled
control          : auto
runtime_active_kids              : 0
runtime_active_time              : 0
runtime_enabled                  : disabled
runtime_status                   : unsupported
runtime_suspended_time           : 0
runtime_usage                    : 0

----
        Have no idea what is real...since runtime usage isn't being kept.
Don't know what aync is in relation to 'power'
says 'active' 0... maybe that means being accessed the moment?
I'd guess locate - writing to that might blink some enclosure light.


> Want proof? Boot a rescue system that
> doesn't load the dmraid stuff and presto, you'll see the separate
> drives that constitute the RAID array.
----
        Not if they are not DM RAID compatible -- I have
booted off of rescue on my old sys that had a similar BIOS-RAID --
rescue saw it as one device as well.


        Note -- I **boot* from my hard disk -- NOT from a ramdisk.

        I don't make a RAM disk to load so my kernel boots.  The kernel
includes all it needs to access the HD -- and loads modules that aren't
mandatory for boot, as needed.


        We might be talking some different terms somewhere or else have
different experiences due to hardware diffs..  But my SW raid in BIOS looks like
1 device to linux and win, (with no way to see what's under/in it), while
my HW raid looks like 1 device for boot, but with the system up, I can
instrospect on the parts.

        The SW (Bios) raid doesn't give me the ability to introspect on the parts --
so the SW only sees it as 1 device.

        That's why I'd be real surprised if GRUB didn't work with this type of SW
RAID (primitive as it is... but sufficient if all you want is a RAID0/RAID1.
I use raid0 for my workstation with small fast disks -- and store all data on
my linux-server.  Ever since the switch to win7, my workstation hasn't been
reliable enough to store data on -- has lost it's disk due to window's 7 eating
them at least three - four times since I've had it.  In no case was there a
HW problem -- but beware Windows system-restore when it can't complete/finish
the restore -- as it tries to roll it back, "to leave your system unchanged",
but doesn't do a very good job sometimes. (30% files randomly 'gone')...  Have
had that happen twice since installed in 2009, and and 2 other times I needed
to restore from an image or reinstall, once, and then reinstall my disk files
over the install and my last registry backup -- restored the system to normal
(for win7 anyway) function...

        Only data loss I had on linux was self-induced -- on a disk that contained
downloadable-content only.  Unfortunately it had grown from something easily
redownloadable to something that took ~ 3-5 months to recover most of the bits and
pieces from.  I now keep a local backup of my downloadable content as well... ;-)


        None of the above touches on why anyone would consider it normal to require
multiple file-systems in order to boot.  I don't even require a RAM disk, whereas
the normal suse boot process uses one, and, at one point, recommended the use of
a non-xfs file system to boot from.  That was caused solely by a bug in grub --
why that wasn't enough to revive LILO as a first-class alternative to grub, I
dunno...   But it was enough to drive me to lilo first-class or not -- that and the
ability to boot from Hard disk and not have to use a RAM disk are bonuses for me --
making boot notably faster.  A moderate sized server coming up in ~25 seconds from
start of kernel load isn't bad -- that time can be more if there are
problems in startup (like network cards no longer talking under Kerns>3.2.x)...
Or if I have left open active snapshot volumes...(those can take a long time to
reconstruct depending on how long the snapshot was going before reboot)...

--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: difference between HW&SW RAIDS as they pertain to / affect booting (et al)

Philipp Thomas-3
On Sat, 25 Aug 2012 16:50:01 -0700, Linda Walsh <[hidden email]>
wrote:

> I see the exact opposite of what you describe.  With the dell
>'virtual disk' SCSI disk device under a "SAS 6iR integrated workstation
>controller, there is nothing visible from any piece of HW that shows me
>the individual parts

You never so much as hinted that you where talking about SAS i.e. SCSI
onboard devices. I thought we were talking about the *much* more
common SATA RAID on consumer level motherboards and with those you
will see what I wrote a number of times.

Workstation boards and onboard SCSI controllers are in a completely
different league and I  believe you that these do hide everything. In
that case bootloaders will only see one device and will work in most
cases.

Philipp
--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: difference between HW&SW RAIDS as they pertain to / affect booting (et al)

L A Walsh
Philipp Thomas wrote:

> On Sat, 25 Aug 2012 16:50:01 -0700, Linda Walsh <[hidden email]>
> wrote:
>
>> I see the exact opposite of what you describe.  With the dell
>> 'virtual disk' SCSI disk device under a "SAS 6iR integrated workstation
>> controller, there is nothing visible from any piece of HW that shows me
>> the individual parts
>
> You never so much as hinted that you where talking about SAS i.e. SCSI
> onboard devices. I thought we were talking about the *much* more
> common SATA RAID on consumer level motherboards and with those you
> will see what I wrote a number of times.
----
        I thought SATA devices were moving toward SAS?   Most of the
disks I have hooked up to my SAS controller ARE 7.2K SATA's.  Among
the disks, only 3/32 devices are really SAS drives, so the detail that
it's a SAS controller isn't something normally first and foremost on my
mind.  It's a very small cost difference to get a SAS controller that handles
both types of drives vs. a SATA-only controller that is far more limited.

        I'd be surprised if many modern machines don't have some inexpensive
option for upgrade.  Dell doesn't offer a SATA-only based workstation controller
for their workstations or servers.  It would take too much work to cripple it
enough to save <1% on some configs (they do offer SATA only configurations, just
not SATA-only controllers  in their workstation line (for the past 12+ years).

        So it never occurred to me that I'd even need to mention such.  Sorry.


--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: difference between HW&SW RAIDS as they pertain to / affect booting (et al)

Philipp Thomas-3
On Sun, 26 Aug 2012 10:46:24 -0700, Linda Walsh <[hidden email]>
wrote:

> I thought SATA devices were moving toward SAS?

No, they're not. They use the same cabling and connectors but there it
ends. That's why you can hook SATA drives to SAS host controllers but
not the other way round as SATA controllers don't speak SCSI over
serial lines.

> Dell doesn't offer a SATA-only based workstation controller
> for their workstations or servers.

Of cause not. But if we're talking workstations and servers we're in a
totally different market with vastly differing prices. Just look at
what you pay for SAS drives or workstation graphics cards like ATI
FireGL or NVidias Quattro. So it needs to be made explicit about what
hardware we're speaking in order to avoid needless discussions.

Philipp
--
To unsubscribe, e-mail: [hidden email]
To contact the owner, e-mail: [hidden email]