Re: LILO error with a raid-1 /
On Wed, 5 Apr 2000, Michael Robinton wrote: raid will boot quite nicely from a standard lilo if the config file is properly set up. I have several raid1 and raid5 (with raid one boot partions) running that use standard lilo on both scsi and ide systems. See, but I didn't change lilos and I only removed unused boot targets and I'm almost certain I didn't change the working boot target (except for it's name). And my lilo is from red hat so it should have the boot from md patches anyway, right? I'm at home at the moment so I will have to post a complete answer with examples config files + explainations tomorrow. Please be patient and I will get you the info. Wonderful, thank you! I'm certainly in no hurry right now :). I won't even need to invoke my patience, I would have sat on hold longer then that to get an answer about any proprietary software ;) Best, Sean
Re: LILO error with a raid-1 /
At 16:26 06.04.00, you wrote: raid will boot quite nicely from a standard lilo if the config file is properly set up. I have several raid1 and raid5 (with raid one boot partions) running that use standard lilo on both scsi and ide systems. Query: is /boot on a raid device that was created in degraed mode (using "failed-disk")? If so, you've got a problem: a) there's a bug in mkraid that resultis in a "phantom" disk if creating arrays in degraded mode and b) there's an incongruity in the raidcode on how to count the number of disks in the array, which makes it impossible to query the raid status of the last disk in an array if there is a failed disk. c) there's a bunch of bugs in the lilo - raidpatch that prevents it from working on arrays with failed disks; the phantom disk from bug a) unfortunately qualifies. I've got patches for a) (fix mkraid diskcount if creating in degraded mode) and c) (make lilo handle failed disks correctly). b) requires a bit more thought and I don't want to do this without feedback from mingo - unfortunately I haven't gotten any reply whatsoever from him so far; tried several times. Bye, martin See, but I didn't change lilos and I only removed unused boot targets and I'm almost certain I didn't change the working boot target (except for it's name). And my lilo is from red hat so it should have the boot from md patches anyway, right? I'm at home at the moment so I will have to post a complete answer with examples config files + explainations tomorrow. Please be patient and I will get you the info. Wonderful, thank you! I'm certainly in no hurry right now :). I won't even need to invoke my patience, I would have sat on hold longer then that to get an answer about any proprietary software ;) Best, Sean "you have moved your mouse, please reboot to make this change take effect" -- Martin Bene vox: +43-316-813824 simon media fax: +43-316-813824-6 Andreas-Hofer-Platz 9 e-mail: [EMAIL PROTECTED] 8010 Graz, Austria -- finger [EMAIL PROTECTED] for PGP public key
Re: LILO error with a raid-1 /
On Thu, 6 Apr 2000, Martin Bene wrote: At 16:26 06.04.00, you wrote: raid will boot quite nicely from a standard lilo if the config file is properly set up. I have several raid1 and raid5 (with raid one boot partions) running that use standard lilo on both scsi and ide systems. Query: is /boot on a raid device that was created in degraed mode (using "failed-disk")? If so, you've got a problem: In this foray into software raid I created two new devices. /dev/md0 was created to hold / and /dev/md1 is for /boot. I created both with the "failed-disk" option with one immediatly following the other. Then I copied my whole system over to the new devices. I left it in failed mode, fixed /etc/fstab and /etc/lilo.conf, ran lilo (worked fine this time with a failed disk in the array), and rebooted. When the system came up on the raid devices properly I fixed up the partitions on the "failed" drive and did raidhotadd for both, it resync and I left it running. It was under this "step" that a day later I tried to run lilo (now with both drives in normal raid functioning) and it failed. So I guess perhaps that is the source of the problem unless I'm misunderstanding you? It didn't occur to me that anything would be different before and after raidhotadding (especially after messages on this list saying it worked fine). a) there's a bug in mkraid that resultis in a "phantom" disk if creating arrays in degraded mode and b) there's an incongruity in the raidcode on how to count the number of disks in the array, which makes it impossible to query the raid status of the last disk in an array if there is a failed disk. c) there's a bunch of bugs in the lilo - raidpatch that prevents it from working on arrays with failed disks; the phantom disk from bug a) unfortunately qualifies. I've got patches for a) (fix mkraid diskcount if creating in degraded mode) and c) (make lilo handle failed disks correctly). So with the fix for A) I would have to end up backing up my data and recreating the raid-1 array anyway? I'm not opposed to doing this (in fact, I was prepared for it if the "failed-disk" method didn't work. If you think this will solve my problem could I get the patch(es) from you and try it? b) requires a bit more thought and I don't want to do this without feedback from mingo - unfortunately I haven't gotten any reply whatsoever from him so far; tried several times. On my array I have a raid-5 array setup at /dev/md3 that already existed before I did any of this. However, all the drives in that array are at the "beginning" according to the way linux assigns the device names. My /dev/md0 and /dev/md1 are on the last two drives (as linux labeling goes). So would the "last disk" be /dev/md3 because it's the last md device or /dev/md(0|1) since it has the last physical disk? (note: no, there is no /dev/md2 currently) Thanks for the help :) Sean Bye, martin "you have moved your mouse, please reboot to make this change take effect" -- Martin Bene vox: +43-316-813824 simon media fax: +43-316-813824-6 Andreas-Hofer-Platz 9 e-mail: [EMAIL PROTECTED] 8010 Graz, Austria -- finger [EMAIL PROTECTED] for PGP public key
Power Supply for multiple disks?
I'm playing a bit with Linux RAID and now I have a question about the power supply. When I use 3 or 4 modern IDE drives I guess they will consume a lot of energy. Do I need a special power supply like 300 W or what are you using? What about "IDE power down when idle"? Can this blow up the power supply or crash the system when turning on 4 disks simultaneous? Sven
Re: LILO error with a raid-1 /
At 17:07 06.04.00, you wrote: In this foray into software raid I created two new devices. /dev/md0 was created to hold / and /dev/md1 is for /boot. I created both with the "failed-disk" option with one immediatly following the other. Then I copied my whole system over to the new devices. I left it in failed mode, fixed /etc/fstab and /etc/lilo.conf, ran lilo (worked fine this time with a failed disk in the array), and rebooted. The "mkraid in failed mode" bug and the "raid handling of remove/add/fail disk" problem cancel each other out in this state. mkraid in failed modes sets the number of disks 1 too high; normal raid code in degraded mode sets it 1 too low; - create degraded array in degraded mode gives the correct number of disks. only when you hotadd the original disk do you get a bad count. When the system came up on the raid devices properly I fixed up the partitions on the "failed" drive and did raidhotadd for both, it resync and I left it running. It was under this "step" that a day later I tried to run lilo (now with both drives in normal raid functioning) and it failed. So I guess perhaps that is the source of the problem unless I'm misunderstanding you? It didn't occur to me that anything would be different before and after raidhotadding (especially after messages on this list saying it worked fine). It does work fine. the only place where you'll ever see the error is with external programs trying to work on the unterlying physical devices of a raid array; the only known program where the problem surfaces is lilo. So with the fix for A) I would have to end up backing up my data and recreating the raid-1 array anyway? I'm not opposed to doing this (in fact, I was prepared for it if the "failed-disk" method didn't work. I'd just save the contents of /boot somewhere and rebuild that device (without dailed-disk stuff), then restore the copy; no patches needed for this. If you think this will solve my problem could I get the patch(es) from you and try it? You can have a look at the state of your md devices using mkraid /dev/md0 --debug. If you look at the logs, you'll see that in the raid superblock, ND (Number of disks in the array) is 3 instead of 2 for your arrays. Lilo tries to get the physical data for each of the disks and dies a horrible death when it tries to access the (non-existing) 3rd disk. You could use the patch from ftp://ftp.sime.com/pub/linux/raidtools-19990824-0.90.mabene.gz to patch your raidtools. You could put your array(s) in the normal state (correct count of disks) by redoing the raid creation stuff after installing the fixed mkraid executable. Just mount the original /dev/hdaxx partitions again, stop the raid arrays and recreate them in failed mode, copy, raidhotadd... same procedure as before. So would the "last disk" be /dev/md3 because it's the last md device or /dev/md(0|1) since it has the last physical disk? Last disk referes to the last physical disk in each raid array. Final point: I'm not too sure about your lilo.conf file - I don't have any of the bios=0x81 stuff in my config file; here's my config file for a working /boot on raid1 lilo setup: - prompt timeout = 50 vga = normal boot=/dev/md4 # End LILO global section # Linux bootable partition config begins image = /boot/vmlinuz root = /dev/md0 label = Linux read-only - check that the partition you put under boot= is the one containing the /boot filesystem, NOT your / filesystem. Works nicely for me, lilo cycles over the physical disks and makes each of them bootable. Bye, Martin "you have moved your mouse, please reboot to make this change take effect" -- Martin Bene vox: +43-316-813824 simon media fax: +43-316-813824-6 Andreas-Hofer-Platz 9 e-mail: [EMAIL PROTECTED] 8010 Graz, Austria -- finger [EMAIL PROTECTED] for PGP public key
Re: Power Supply for multiple disks?
Sven Kirmess wrote: I'm playing a bit with Linux RAID and now I have a question about the power supply. When I use 3 or 4 modern IDE drives I guess they will consume a lot of energy. Do I need a special power supply like 300 W or what are you using? A high capacity PS is always good to have, esp. in a high uptime box. Having that extra wattage available can prevent power dips from making things flake out. What about "IDE power down when idle"? Can this blow up the power supply or crash the system when turning on 4 disks simultaneous? Doubtful, BUT, Power Management has always been a sore spot for me, I've had millions of Win PCs croak when they try to "wake" from their low power mode. I blame the variety of specs, and variety of BIOS, motherboard, disk, etc. manufacturers. In short, I'd avoid "power down when idle" and similar, if this is a production machine. Ed Sven
Re: Power Supply for multiple disks?
I'm playing a bit with Linux RAID and now I have a question about the power supply. When I use 3 or 4 modern IDE drives I guess they will consume a lot of energy. Cranking up 10K RPM drives will require substantial power. A real crude yardstick is that the 1.0 inch high drives will take less to spin-up than the 1.5 inch high drives (more platters=more mass, inertia) Do I need a special power supply like 300 W or what are you using? What about "IDE power down when idle"? Can this blow up the power supply or crash the system when turning on 4 disks simultaneous? Your specifics will be different than others, so nobody can give you a "yes it will" or "no it won't answer". On the dual (redundant) power supply enclosures I work with, the adapter will only issue "start" commands to 4 drives at a time to reduce the peak loads. Naturally, the drives are config'd not to auto-start at powerup. Regards, Steve (opinions expressed match those of other personalities sharing my cranial space, but are not those of my employer).
Where to get power supply?
Speaking of power supplies, I've been looking for one for my homemade external RAID box. Right now I'm using an old AT PS that I'm sure is going to croak any day. Anybody know where I can get a cheap datacase-type PS with the on/off switch on the PS itself? - David Bradford, Portland, OR[EMAIL PROTECTED] http://www.teleport.com/~dbradfor +1 503 203 1043 -
Re: Power Supply for multiple disks?
Thursday, April 06, 2000, 6:36:39 PM, David wrote: What about "IDE power down when idle"? Can this blow up the power supply or crash the system when turning on 4 disks simultaneous? You don't want to use "power down when idle" on drives in a RAID... Why not? I think about power down after e.g. 30' idle time. Not after a few seconds... What's the Problem with RAID? Does it mark all disks as bad if they don't come up fast enough? Sven
Re: Power Supply for multiple disks?
Thursday, April 06, 2000, 6:44:49 PM, Ed wrote: Do I need a special power supply like 300 W or what are you using? A high capacity PS is always good to have, esp. in a high uptime box. Having that extra wattage available can prevent power dips from making things flake out. What about the quality of cheap 250 W against expensive 250 W power supplys? Does that matter? Here you pay about the same amount of money for a good (I think) power supply than for a case with supply. I could imagine that applications like RAID5 are a real torture, because all disks have to work simultaneous. Especially if the disks are the same type. What about "IDE power down when idle"? Can this blow up the power supply or crash the system when turning on 4 disks simultaneous? Doubtful, BUT, Power Management has always been a sore spot for me, I've had millions of Win PCs croak when they try to "wake" from their low power mode. I blame the variety of specs, and variety of BIOS, motherboard, disk, etc. manufacturers. In short, I'd avoid "power down when idle" and similar, if this is a production machine. It's not a productive machine. I just don't like inconsistency on a disk. :-) Sven
Re: Where to get power supply?
On Thu, 6 Apr 2000, David Bradford wrote: Speaking of power supplies, I've been looking for one for my homemade external RAID box. Right now I'm using an old AT PS that I'm sure is going to croak any day. Anybody know where I can get a cheap datacase-type PS with the on/off switch on the PS itself? I've used a home made 6 disk raid 5 array for about a year using a standard AT bigtower case. These disks are old 2GB 1.6" differential SCSI drives, so not exactly the low-power type of disks. This worked fine, even with direct power up. The drives generated lots of heat, but then I used lots of fans to compensate :) This was just for a home system, I wouldn't use it for a production system, but it did work fine. (it still does, but using fewer larger disks was more efficient...) -- Tot ziens, Bart-Jan
Re: Power Supply for multiple disks?
On Thu, 06 Apr 2000, Sven Kirmess wrote:
Thursday, April 06, 2000, 6:36:39 PM, David wrote:
What about "IDE power down when idle"? Can this blow up the power
supply or crash the system when turning on 4 disks simultaneous?
You don't want to use "power down when idle" on drives in a RAID...
Why not? I think about power down after e.g. 30' idle time. Not after
a few seconds... What's the Problem with RAID? Does it mark all disks
as bad if they don't come up fast enough?
It definitely shouldn't. That would be a bug in the drive if you got
a read/write failure after power down.
On a home system where the disks can potentially be idle for a long
time, you could probably spin the disks down. On a production system
where users expect a prompt reply from the system, powering down the
disks is outright stupid.
But I fail to see how this relates to the size of the PSU ? All disks
must run when you use them, and if you need a 300W PSU to do that, you
can't use a 150W even if your disks are only in use 50% of the day.
(Obviously)
By the way, a lot of modern IDE drives have a jumper setting that
will delay their spin-up, so you could have your drives spinning up
only a few at a time to reduce the peak load, even with cheap disks.
At least some IBM disks has this feature (unsure about others)
--
: [EMAIL PROTECTED] : And I see the elder races, :
:.: putrid forms of man:
: Jakob Østergaard : See him rise and claim the earth, :
:OZ9ABN : his downfall is at hand. :
:.:{Konkhra}...:
Re: Where to get power supply?
On Thu, Apr 06, 2000 at 10:55:24AM -0700, David Bradford wrote: Speaking of power supplies, I've been looking for one for my homemade external RAID box. Right now I'm using an old AT PS that I'm sure is going to croak any day. Anybody know where I can get a cheap datacase-type PS with the on/off switch on the PS itself? I think you want an 'AT' type power supply (it has a on-off, instead of the 'auto' type which ATX has). Also, I thought I would share an experience of using a Siliconrax rack-mount case with redundant hot-swap power supplies. The case was $700 from Fry's. No special hardware or software needed, it just has the regular ATX and power tap connectors. The case has a fault light an alarm if one of the power supplies fail. Pretty neat! Phil -- Philip Edelbrock -- IS Manager -- Edge Design, Corvallis, OR [EMAIL PROTECTED] -- http://www.netroedge.com/~phil PGP F16: 01 D2 FD 01 B5 46 F4 F0 3A 8B 9D 7E 14 7F FB 7A
Re: Power Supply for multiple disks?
Thursday, April 06, 2000, 10:08:59 PM, Jakob wrote: Sorry, but I have to say it. Very, very good HOWTO. Thanks. Why not? I think about power down after e.g. 30' idle time. Not after a few seconds... What's the Problem with RAID? Does it mark all disks as bad if they don't come up fast enough? It definitely shouldn't. That would be a bug in the drive if you got a read/write failure after power down. But Linux may have a timeout...? On a home system where the disks can potentially be idle for a long time, you could probably spin the disks down. On a production system where users expect a prompt reply from the system, powering down the disks is outright stupid. Of course it isn't a productive system. But I fail to see how this relates to the size of the PSU ? All disks must run when you use them, and if you need a 300W PSU to do that, you can't use a 150W even if your disks are only in use 50% of the day. (Obviously) I know that of course. My question was more like "Is there a power problem with a couple of IDE disks?" or "are you running special supplys?". I won't create a RAID system and loose more data because of a too weak supply than I would loose during a disk failure. By the way, a lot of modern IDE drives have a jumper setting that will delay their spin-up, so you could have your drives spinning up only a few at a time to reduce the peak load, even with cheap disks. At least some IBM disks has this feature (unsure about others) But this will slow down the wake process even more and maybe lead to more misinterpretation of the disk status...? Sven
Re: Power Supply for multiple disks?
On Fri, 07 Apr 2000, Sven Kirmess wrote:
Thursday, April 06, 2000, 10:08:59 PM, Jakob wrote:
Sorry, but I have to say it. Very, very good HOWTO. Thanks.
*Blush*:)
Why not? I think about power down after e.g. 30' idle time. Not
after a few seconds... What's the Problem with RAID? Does it mark
all disks as bad if they don't come up fast enough?
It definitely shouldn't. That would be a bug in the drive if you got
a read/write failure after power down.
But Linux may have a timeout...?
You're right. It has none that I know of. I would be surprised if
there was a timeout (I'm really sure there isn't), as this would be
some experimental value that you could never really give a ``right''
value.
On a home system where the disks can potentially be idle for a long
time, you could probably spin the disks down. On a production system
where users expect a prompt reply from the system, powering down the
disks is outright stupid.
Of course it isn't a productive system.
But I fail to see how this relates to the size of the PSU ? All
disks must run when you use them, and if you need a 300W PSU to do
that, you can't use a 150W even if your disks are only in use 50% of
the day. (Obviously)
I know that of course. My question was more like "Is there a power
problem with a couple of IDE disks?" or "are you running special
supplys?".
We have six 6G old Quantum SCSI disks in a home-made RAID tower here.
The disks spin up all at the same time (they're to stupid/old to do
anything else), and they run of a cheap AT PSU. No problems, but
I have no idea what the load is on the PSU when they spin up.
I won't create a RAID system and loose more data because of a too weak
supply than I would loose during a disk failure.
I think that if you get past a synchronous spinup, you'll survive
anything that might happen during use. But this is all a ``may''
and ``might'' discussion...
By the way, a lot of modern IDE drives have a jumper setting that
will delay their spin-up, so you could have your drives spinning up
only a few at a time to reduce the peak load, even with cheap disks.
At least some IBM disks has this feature (unsure about others)
But this will slow down the wake process even more and maybe lead to
more misinterpretation of the disk status...?
It will slow the wakeup process if the disks also delay wakeups
after the initial power-on. I don't know what the disks would do,
it probably even depends on vendors too, just to make this whole
thing even more interesting:)
--
: [EMAIL PROTECTED] : And I see the elder races, :
:.: putrid forms of man:
: Jakob Østergaard : See him rise and claim the earth, :
:OZ9ABN : his downfall is at hand. :
:.:{Konkhra}...:
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