Hi,
I am running raid 1 on a centos 4.4. One of the harddisk (sda1) failed. How can i carry on running the server using only sda2?
Thank you
CentOS List wrote:
Hi,
I am running raid 1 on a centos 4.4. One of the harddisk (sda1) failed. How can i carry on running the server using only sda2?
Generate a grub floppy and use that to load the grub menu from the sdb (probably now sda) disk.
If you are really talking about sda1 and sda2, those are partitions on the same disk.
CentOS List wrote:
Hi,
I am running raid 1 on a centos 4.4. One of the harddisk (sda1) failed. How can i carry on running the server using only sda2?
Generate a grub floppy and use that to load the grub menu from the sdb (probably now sda) disk.
If you are really talking about sda1 and sda2, those are partitions on the same disk.
Is there a detail step by step howto? The raid 1 has no LVM. just md0, md1 and md2. md0 is /boot, md1 is swap and md2 is the storage. I had replace sba with a new disk. I tried to boot up and it says kernel panic. How am i going to reconstruct the raid and sync sdb to sda?
best regards
On 4/27/07, CentOS List centoslist@gmail.com wrote:
CentOS List wrote:
Hi,
I am running raid 1 on a centos 4.4. One of the harddisk (sda1) failed. How can i carry on running the server using only sda2?
Generate a grub floppy and use that to load the grub menu from the sdb (probably now sda) disk.
If you are really talking about sda1 and sda2, those are partitions on the same disk.
Is there a detail step by step howto? The raid 1 has no LVM. just md0, md1 and md2. md0 is /boot, md1 is swap and md2 is the storage. I had replace sba with a new disk. I tried to boot up and it says kernel panic. How am i going to reconstruct the raid and sync sdb to sda?
You might find these notes http://ex-parrot.com/~pete/software-raid-howto.html handy- but I can't confirm they are 100% correct for you- you have to work that out yourself.
If you have the ability to clone the surviving drive to another drive as an extra backup on top of the one you already have (of course you do?) I'd do that before potentially accidentally screwing up this disk as well!
Cheers,
A.D.
CentOS List wrote:
I am running raid 1 on a centos 4.4. One of the harddisk (sda1) failed. How can i carry on running the server using only sda2?
Generate a grub floppy and use that to load the grub menu from the sdb (probably now sda) disk.
If you are really talking about sda1 and sda2, those are partitions on the same disk.
Is there a detail step by step howto? The raid 1 has no LVM. just md0, md1 and md2. md0 is /boot, md1 is swap and md2 is the storage. I had replace sba with a new disk. I tried to boot up and it says kernel panic. How am i going to reconstruct the raid and sync sdb to sda?
It might be easier to swap the old sdb into the sda position so you'll boot from it, but you should also be able to boot the install cd with 'linux rescue' at the boot prompt, let it detect and mount your system (which will be the 'broken' raid devices with their single members), then do the chroot command it suggests. From there you can fdisk matching partitions on the new sda disk (if you didn't swap) and use mdadm to add them to the RAIDs. Or you can just install grub on sda so you can reboot normally, then sync the mirrors with mdadm after you are running.
I am running raid 1 on a centos 4.4. One of the harddisk (sda1) failed. How can i carry on running the server using only sda2?
Generate a grub floppy and use that to load the grub menu from the sdb (probably now sda) disk.
If you are really talking about sda1 and sda2, those are partitions on the same disk.
Is there a detail step by step howto? The raid 1 has no LVM. just md0, md1 and md2. md0 is /boot, md1 is swap and md2 is the storage. I had replace sba with a new disk. I tried to boot up and it says kernel panic. How am i going to reconstruct the raid and sync sdb to sda?
It might be easier to swap the old sdb into the sda position so you'll boot from it, but you should also be able to boot the install cd with
If swapped and booted, and got a kernel panic error.
'linux rescue' at the boot prompt, let it detect and mount your system (which will be the 'broken' raid devices with their single members),
If i use linux rescue, The 3 mds I created are gone. /cat /proc/mdstat says Personalitlies: [raid0] [raid1] [raid5] [raid6], no longer Personalities : [raid1]
It might be easier to swap the old sdb into the sda position so you'll boot from it, but you should also be able to boot the install cd with
If swapped and booted, and got a kernel panic error.
What does it complain about?
<snip> mounting root filesystem cfs: can't find ext3 filesystem on dev md2 mount: error 22 mounting ext mount: error 22 mounting none switching to new root switchroot: mount failed: 22 unmount /initrd/dev failed: 2 Kernel panic - not syncing: attempted to kill init!
CentOS List wrote:
It might be easier to swap the old sdb into the sda position so you'll boot from it, but you should also be able to boot the install cd with
If swapped and booted, and got a kernel panic error.
What does it complain about?
<snip> mounting root filesystem cfs: can't find ext3 filesystem on dev md2 mount: error 22 mounting ext mount: error 22 mounting none switching to new root switchroot: mount failed: 22 unmount /initrd/dev failed: 2 Kernel panic - not syncing: attempted to kill init!
From the rescue mode boot, can you mount either /dev/md2 or the underlying /dev/sd?2 from either of the disks. If not, the raid isn't your problem, it is the contents of the partition.
It might be easier to swap the old sdb into the sda position so you'll boot from it, but you should also be able to boot the install cd with
If swapped and booted, and got a kernel panic error.
What does it complain about?
<snip> mounting root filesystem cfs: can't find ext3 filesystem on dev md2 mount: error 22 mounting ext mount: error 22 mounting none switching to new root switchroot: mount failed: 22 unmount /initrd/dev failed: 2 Kernel panic - not syncing: attempted to kill init!
From the rescue mode boot, can you mount either /dev/md2 or the underlying /dev/sd?2 from either of the disks. If not, the raid isn't your problem, it is the contents of the partition.
# mount /dev/md2 /mnt/part3 mount: Mounting /dev/md2 on /mnt/part3 failed: Invalid argument
CentOS List wrote:
It might be easier to swap the old sdb into the sda position so you'll boot from it, but you should also be able to boot the install cd with
If swapped and booted, and got a kernel panic error.
What does it complain about?
<snip> mounting root filesystem cfs: can't find ext3 filesystem on dev md2 mount: error 22 mounting ext mount: error 22 mounting none switching to new root switchroot: mount failed: 22 unmount /initrd/dev failed: 2 Kernel panic - not syncing: attempted to kill init!
From the rescue mode boot, can you mount either /dev/md2 or the underlying /dev/sd?2 from either of the disks. If not, the raid isn't your problem, it is the contents of the partition.
# mount /dev/md2 /mnt/part3 mount: Mounting /dev/md2 on /mnt/part3 failed: Invalid argument
What about the /dev/sda2 or /dev/sdb2 that was the original disk? If you can't mount the filesystem from there, I think the contents either weren't what you thought (the raid wasn't working before the other drive failed) or something you have done since has damaged it.
CentOS List wrote:
I am running raid 1 on a centos 4.4. One of the harddisk (sda1) failed. How can i carry on running the server using only sda2?
Generate a grub floppy and use that to load the grub menu from the sdb (probably now sda) disk.
If you are really talking about sda1 and sda2, those are partitions on the same disk.
Is there a detail step by step howto? The raid 1 has no LVM. just md0, md1 and md2. md0 is /boot, md1 is swap and md2 is the storage. I had replace sba with a new disk. I tried to boot up and it says kernel panic. How am i going to reconstruct the raid and sync sdb to sda?
It might be easier to swap the old sdb into the sda position so you'll boot from it, but you should also be able to boot the install cd with
If swapped and booted, and got a kernel panic error.
'linux rescue' at the boot prompt, let it detect and mount your system (which will be the 'broken' raid devices with their single members),
If i use linux rescue, The 3 mds I created are gone. /cat /proc/mdstat says Personalitlies: [raid0] [raid1] [raid5] [raid6], no longer Personalities : [raid1]
Perhaps your raid wasn't really working the way you thought before. From the rescue boot, does fdisk show the 3 partitions on the old disk with type 'fd'? Can you mount the old /boot and / partitions somewhere by hand? You should be able to do this with the /dev/sda1 and /dev/sda3 device names if the md devices aren't detected at boot.
CentOS List wrote:
I am running raid 1 on a centos 4.4. One of the harddisk (sda1) failed. How can i carry on running the server using only sda2?
Generate a grub floppy and use that to load the grub menu from the sdb (probably now sda) disk.
If you are really talking about sda1 and sda2, those are partitions on the same disk.
Is there a detail step by step howto? The raid 1 has no LVM. just md0, md1 and md2. md0 is /boot, md1 is swap and md2 is the storage. I had replace sba with a new disk. I tried to boot up and it says kernel panic. How am i going to reconstruct the raid and sync sdb to sda?
It might be easier to swap the old sdb into the sda position so you'll boot from it, but you should also be able to boot the install cd with
If swapped and booted, and got a kernel panic error.
'linux rescue' at the boot prompt, let it detect and mount your system (which will be the 'broken' raid devices with their single members),
If i use linux rescue, The 3 mds I created are gone. /cat /proc/mdstat says Personalitlies: [raid0] [raid1] [raid5] [raid6], no longer Personalities : [raid1]
Perhaps your raid wasn't really working the way you thought before. From the rescue boot, does fdisk show the 3 partitions on the old disk with type 'fd'? Can you mount the old /boot and / partitions somewhere by hand? You should be able to do this with the /dev/sda1 and /dev/sda3 device names if the md devices aren't detected at boot.
cat /proc/partitions still shows me the 3 partitions. I actually copied /boot to the "replaced disk" and it is able to boot up, but without any filesystem, so i guess the boot is still intact. So do i need to mount /boot and /?
CentOS List wrote:
CentOS List wrote:
> I am running raid 1 on a centos 4.4. One of the harddisk (sda1) > failed. How can i carry on running the server using only sda2?
Generate a grub floppy and use that to load the grub menu from the sdb (probably now sda) disk.
If you are really talking about sda1 and sda2, those are partitions on the same disk.
Is there a detail step by step howto? The raid 1 has no LVM. just md0, md1 and md2. md0 is /boot, md1 is swap and md2 is the storage. I had replace sba with a new disk. I tried to boot up and it says kernel panic. How am i going to reconstruct the raid and sync sdb to sda?
It might be easier to swap the old sdb into the sda position so you'll boot from it, but you should also be able to boot the install cd with
If swapped and booted, and got a kernel panic error.
'linux rescue' at the boot prompt, let it detect and mount your system (which will be the 'broken' raid devices with their single members),
If i use linux rescue, The 3 mds I created are gone. /cat /proc/mdstat says Personalitlies: [raid0] [raid1] [raid5] [raid6], no longer Personalities : [raid1]
Perhaps your raid wasn't really working the way you thought before. From the rescue boot, does fdisk show the 3 partitions on the old disk with type 'fd'? Can you mount the old /boot and / partitions somewhere by hand? You should be able to do this with the /dev/sda1 and /dev/sda3 device names if the md devices aren't detected at boot.
cat /proc/partitions still shows me the 3 partitions.
Does fdisk say that they are type 'fd'(raid autodetect)?
I actually copied /boot to the "replaced disk" and it is able to boot up, but without any filesystem, so i guess the boot is still intact. So do i need to mount /boot and /?
If you can get the original partitions to be detected as their md devices you should fdisk matching partitions on the replacement disk, then 'mdadm --add ...' to add them and they will automatically sync up.
CentOS List wrote:
CentOS List wrote:
>> I am running raid 1 on a centos 4.4. One of the harddisk (sda1) >> failed. How can i carry on running the server using only sda2? > > Generate a grub floppy and use that to load the grub menu from the > sdb (probably now sda) disk. > > If you are really talking about sda1 and sda2, those are > partitions on the same disk.
Is there a detail step by step howto? The raid 1 has no LVM. just md0, md1 and md2. md0 is /boot, md1 is swap and md2 is the storage. I had replace sba with a new disk. I tried to boot up and it says kernel panic. How am i going to reconstruct the raid and sync sdb to sda?
It might be easier to swap the old sdb into the sda position so you'll boot from it, but you should also be able to boot the install cd with
If swapped and booted, and got a kernel panic error.
'linux rescue' at the boot prompt, let it detect and mount your system (which will be the 'broken' raid devices with their single members),
If i use linux rescue, The 3 mds I created are gone. /cat /proc/mdstat says Personalitlies: [raid0] [raid1] [raid5] [raid6], no longer Personalities : [raid1]
Perhaps your raid wasn't really working the way you thought before. From the rescue boot, does fdisk show the 3 partitions on the old disk with type 'fd'? Can you mount the old /boot and / partitions somewhere by hand? You should be able to do this with the /dev/sda1 and /dev/sda3 device names if the md devices aren't detected at boot.
cat /proc/partitions still shows me the 3 partitions.
Does fdisk say that they are type 'fd'(raid autodetect)?
Yes. There are 3 fd (raid autodetect)
I actually copied /boot to the "replaced disk" and it is able to boot up, but without any filesystem, so i guess the boot is still intact. So do i need to mount /boot and /?
If you can get the original partitions to be detected as their md devices you should fdisk matching partitions on the replacement disk, then 'mdadm --add ...' to add them and they will automatically sync up.
So I just have to manually add md to the 3 partitions?
regards
CentOS List wrote:
CentOS List wrote:
>> I am running raid 1 on a centos 4.4. One of the harddisk (sda1) >> failed. How can i carry on running the server using only sda2? > > Generate a grub floppy and use that to load the grub menu from the > sdb (probably now sda) disk. > > If you are really talking about sda1 and sda2, those are partitions > on the same disk.
Is there a detail step by step howto? The raid 1 has no LVM. just md0, md1 and md2. md0 is /boot, md1 is swap and md2 is the storage. I had replace sba with a new disk. I tried to boot up and it says kernel panic. How am i going to reconstruct the raid and sync sdb to sda?
It might be easier to swap the old sdb into the sda position so you'll boot from it, but you should also be able to boot the install cd with
If swapped and booted, and got a kernel panic error.
'linux rescue' at the boot prompt, let it detect and mount your system (which will be the 'broken' raid devices with their single members),
If i use linux rescue, The 3 mds I created are gone. /cat /proc/mdstat says Personalitlies: [raid0] [raid1] [raid5] [raid6], no longer Personalities : [raid1]
Perhaps your raid wasn't really working the way you thought before. From the rescue boot, does fdisk show the 3 partitions on the old disk with type 'fd'? Can you mount the old /boot and / partitions somewhere by hand? You should be able to do this with the /dev/sda1 and /dev/sda3 device names if the md devices aren't detected at boot.
cat /proc/partitions still shows me the 3 partitions.
Does fdisk say that they are type 'fd'(raid autodetect)?
I actually copied /boot to the "replaced disk" and it is able to boot up, but without any filesystem, so i guess the boot is still intact. So do i need to mount /boot and /?
If you can get the original partitions to be detected as their md devices you should fdisk matching partitions on the replacement disk, then 'mdadm --add ...' to add them and they will automatically sync up.
mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1 mdadm --create --verbose /dev/md1 --level=1 --raid-devices=2 /dev/sda2 /dev/sdb2 mdadm --create --verbose /dev/md2 --level=1 --raid-devices=2 /dev/sda3 /dev/sdb3
After that i reboot and got the kernel panic again.
md: considering sdb1 md: adding sdb1 md: created md0 md: bind<sda1> md: running: <sdb1><sda1> raid1: raid set md0 active with 2 out of 2 mirrors md: ... autorun DONE md: autodetcting RAID arrays md:mautorun ... Creating root device Mounting root filesystem switching to new root switchroot: mount failed: 22 umount /unitrd/dev failed: 2 Kernel panic
CentOS List wrote:
CentOS List wrote:
CentOS List wrote:
>>> I am running raid 1 on a centos 4.4. One of the harddisk (sda1) >>> failed. How can i carry on running the server using only sda2? >> >> Generate a grub floppy and use that to load the grub menu from >> the sdb (probably now sda) disk. >> >> If you are really talking about sda1 and sda2, those are >> partitions on the same disk. > > Is there a detail step by step howto? The raid 1 has no LVM. just > md0, md1 and md2. md0 is /boot, md1 is swap and md2 is the > storage. I had replace sba with a new disk. I tried to boot up > and it says kernel panic. How am i going to reconstruct the raid > and sync sdb to sda?
It might be easier to swap the old sdb into the sda position so you'll boot from it, but you should also be able to boot the install cd with
If swapped and booted, and got a kernel panic error.
'linux rescue' at the boot prompt, let it detect and mount your system (which will be the 'broken' raid devices with their single members),
If i use linux rescue, The 3 mds I created are gone. /cat /proc/mdstat says Personalitlies: [raid0] [raid1] [raid5] [raid6], no longer Personalities : [raid1]
Perhaps your raid wasn't really working the way you thought before. From the rescue boot, does fdisk show the 3 partitions on the old disk with type 'fd'? Can you mount the old /boot and / partitions somewhere by hand? You should be able to do this with the /dev/sda1 and /dev/sda3 device names if the md devices aren't detected at boot.
cat /proc/partitions still shows me the 3 partitions.
Does fdisk say that they are type 'fd'(raid autodetect)?
I actually copied /boot to the "replaced disk" and it is able to boot up, but without any filesystem, so i guess the boot is still intact. So do i need to mount /boot and /?
If you can get the original partitions to be detected as their md devices you should fdisk matching partitions on the replacement disk, then 'mdadm --add ...' to add them and they will automatically sync up.
mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1 mdadm --create --verbose /dev/md1 --level=1 --raid-devices=2 /dev/sda2 /dev/sdb2 mdadm --create --verbose /dev/md2 --level=1 --raid-devices=2 /dev/sda3 /dev/sdb3
If you already had raid devices on one of the disks you should not have had to --create them again. The original ones should have been detected and you should have been able to --add new matching partitions.
After that i reboot and got the kernel panic again.
md: considering sdb1 md: adding sdb1 md: created md0 md: bind<sda1> md: running: <sdb1><sda1> raid1: raid set md0 active with 2 out of 2 mirrors md: ... autorun DONE md: autodetcting RAID arrays md:mautorun ... Creating root device Mounting root filesystem switching to new root switchroot: mount failed: 22 umount /unitrd/dev failed: 2 Kernel panic
When you --create a new raid it will start to sync the mirrors. It may have done this the wrong direction, overwriting your old contents. Can you still do a rescue mode boot, mount /dev/sda3 (or sdb3 if the old drive is in the 2nd position) and see the contents?
Les Mikesell wrote:
CentOS List wrote:
CentOS List wrote:
CentOS List wrote:
>>>> I am running raid 1 on a centos 4.4. One of the harddisk >>>> (sda1) failed. How can i carry on running the server using >>>> only sda2? >>> >>> Generate a grub floppy and use that to load the grub menu from >>> the sdb (probably now sda) disk. >>> >>> If you are really talking about sda1 and sda2, those are >>> partitions on the same disk. >> >> Is there a detail step by step howto? The raid 1 has no LVM. >> just md0, md1 and md2. md0 is /boot, md1 is swap and md2 is the >> storage. I had replace sba with a new disk. I tried to boot up >> and it says kernel panic. How am i going to reconstruct the raid >> and sync sdb to sda? > > It might be easier to swap the old sdb into the sda position so > you'll boot from it, but you should also be able to boot the > install cd with
If swapped and booted, and got a kernel panic error.
> 'linux rescue' at the boot prompt, let it detect and mount your > system (which will be the 'broken' raid devices with their single > members),
If i use linux rescue, The 3 mds I created are gone. /cat /proc/mdstat says Personalitlies: [raid0] [raid1] [raid5] [raid6], no longer Personalities : [raid1]
Perhaps your raid wasn't really working the way you thought before. From the rescue boot, does fdisk show the 3 partitions on the old disk with type 'fd'? Can you mount the old /boot and / partitions somewhere by hand? You should be able to do this with the /dev/sda1 and /dev/sda3 device names if the md devices aren't detected at boot.
cat /proc/partitions still shows me the 3 partitions.
Does fdisk say that they are type 'fd'(raid autodetect)?
I actually copied /boot to the "replaced disk" and it is able to boot up, but without any filesystem, so i guess the boot is still intact. So do i need to mount /boot and /?
If you can get the original partitions to be detected as their md devices you should fdisk matching partitions on the replacement disk, then 'mdadm --add ...' to add them and they will automatically sync up.
mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1 mdadm --create --verbose /dev/md1 --level=1 --raid-devices=2 /dev/sda2 /dev/sdb2 mdadm --create --verbose /dev/md2 --level=1 --raid-devices=2 /dev/sda3 /dev/sdb3
If you already had raid devices on one of the disks you should not have had to --create them again. The original ones should have been detected and you should have been able to --add new matching partitions.
After that i reboot and got the kernel panic again.
md: considering sdb1 md: adding sdb1 md: created md0 md: bind<sda1> md: running: <sdb1><sda1> raid1: raid set md0 active with 2 out of 2 mirrors md: ... autorun DONE md: autodetcting RAID arrays md:mautorun ... Creating root device Mounting root filesystem switching to new root switchroot: mount failed: 22 umount /unitrd/dev failed: 2 Kernel panic
When you --create a new raid it will start to sync the mirrors. It may have done this the wrong direction, overwriting your old contents. Can you still do a rescue mode boot, mount /dev/sda3 (or sdb3 if the old drive is in the 2nd position) and see the contents?
Oops - that would be sda2/sdb2 there - they start from 0.
>>>> I am running raid 1 on a centos 4.4. One of the harddisk (sda1) >>>> failed. How can i carry on running the server using only sda2? >>> >>> Generate a grub floppy and use that to load the grub menu from >>> the sdb (probably now sda) disk. >>> >>> If you are really talking about sda1 and sda2, those are >>> partitions on the same disk. >> >> Is there a detail step by step howto? The raid 1 has no LVM. just >> md0, md1 and md2. md0 is /boot, md1 is swap and md2 is the >> storage. I had replace sba with a new disk. I tried to boot up >> and it says kernel panic. How am i going to reconstruct the raid >> and sync sdb to sda? > > It might be easier to swap the old sdb into the sda position so > you'll boot from it, but you should also be able to boot the > install cd with
If swapped and booted, and got a kernel panic error.
> 'linux rescue' at the boot prompt, let it detect and mount your > system (which will be the 'broken' raid devices with their single > members),
If i use linux rescue, The 3 mds I created are gone. /cat /proc/mdstat says Personalitlies: [raid0] [raid1] [raid5] [raid6], no longer Personalities : [raid1]
Perhaps your raid wasn't really working the way you thought before. From the rescue boot, does fdisk show the 3 partitions on the old disk with type 'fd'? Can you mount the old /boot and / partitions somewhere by hand? You should be able to do this with the /dev/sda1 and /dev/sda3 device names if the md devices aren't detected at boot.
cat /proc/partitions still shows me the 3 partitions.
Does fdisk say that they are type 'fd'(raid autodetect)?
I actually copied /boot to the "replaced disk" and it is able to boot up, but without any filesystem, so i guess the boot is still intact. So do i need to mount /boot and /?
If you can get the original partitions to be detected as their md devices you should fdisk matching partitions on the replacement disk, then 'mdadm --add ...' to add them and they will automatically sync up.
mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1 mdadm --create --verbose /dev/md1 --level=1 --raid-devices=2 /dev/sda2 /dev/sdb2 mdadm --create --verbose /dev/md2 --level=1 --raid-devices=2 /dev/sda3 /dev/sdb3
If you already had raid devices on one of the disks you should not have had to --create them again. The original ones should have been detected and you should have been able to --add new matching partitions.
I created them as md(s) are not longer there.
After that i reboot and got the kernel panic again.
md: considering sdb1 md: adding sdb1 md: created md0 md: bind<sda1> md: running: <sdb1><sda1> raid1: raid set md0 active with 2 out of 2 mirrors md: ... autorun DONE md: autodetcting RAID arrays md:mautorun ... Creating root device Mounting root filesystem switching to new root switchroot: mount failed: 22 umount /unitrd/dev failed: 2 Kernel panic
When you --create a new raid it will start to sync the mirrors. It may have done this the wrong direction, overwriting your old contents. Can you still do a rescue mode boot, mount /dev/sda3 (or sdb3 if the old drive is in the 2nd position) and see the contents?
I am unable to mount sda3.
# mount /dev/sda3 /mnt/part3 mount: Mounting /dev/sda3 on /mnt failed: Invalid argument
sdb is not longer detectable.
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Feizhou -
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Tony