software raid drive failed, please provide step bu steptorebuild
jvian10 at charter.net
Sat Jul 29 01:12:49 UTC 2006
On Fri, 2006-07-28 at 19:37 -0500, Dan Carl wrote:
> Ok I totally see your point about striping my swap partition.
> I read it some howto a few years back.
> I did just what you said
> I paritioned my new drive the exact same as the other two.
> I issued the command
> mdadm /dev/md2 -a /dev/sdc3
> and the raid md2 is rebuilding as I write this.
> So how do I get setup my swap as you described?
> Now I have three drives w/ partition
> 265072 sda2
> 265072 sdb2
> 265072 sdc2
First format the swap partitions. Note that fdisk should list these as
type 82 Linux swap.
repeat for sdb2 and sdc2
then put into fstab the following
/dev/sda2 swap swap defaults 0 0
/dev/sdb2 swap swap defaults 0 0
/dev/sdc2 swap swap defaults 0 0
Finally just issue the "swapon -a" command to enable swap as defined.
Now if one fails the remaining ones will continue to be used.
> Thank you soooo much
> Its 100 degrees, its Friday and now I have go outside and mow my lawn.
> Look forward to reading your reply while sipping a cold one!
> ----- Original Message -----
> From: "Jeff Vian" <jvian10 at charter.net>
> To: "For users of Fedora Core releases" <fedora-list at redhat.com>
> Sent: Friday, July 28, 2006 6:48 PM
> Subject: Re: software raid drive failed, please provide step bu
> > On Fri, 2006-07-28 at 18:03 -0500, Dan Carl wrote:
> >> I know its a raid 0 is a stripe.
> >> Its my swap partition.
> >> Why would I need fault tolerance on my swap.
> >>From your first post below:
> > Now I can reach the drive via fdisk but I have made more
> > problems now (no swap now)
> > and I'm not sure the steps to rebuild.
> > That is a good reason to make sure that vital disk partitions are not
> > made critically weak. When striping across 3 drives the failure
> > probability is made 3X as likely and any single failure toasts the
> > entire device.
> > Since swap can use multiple partitions the likelyhood of failure and
> > total loss of swap space can be reduced by simply defining multiple swap
> > partitions without using striping.
> >> Anyway,
> >> I did what Sam suggested.
> >> md0 is fine, md1 doesn't exist
> >> mdadm -Q -D /dev/md2
> >> it yeilded
> >> /dev/md2:
> >> Version : 00.90.01
> >> Creation Time : Mon Feb 14 06:42:28 2005
> >> Raid Level : raid5
> >> Array Size : 34812416 (33.20 GiB 35.65 GB)
> >> Device Size : 17406208 (16.60 GiB 17.82 GB)
> >> Raid Devices : 3
> >> Total Devices : 2
> >> Preferred Minor : 2
> >> Persistence : Superblock is persistent
> >> Update Time : Fri Jul 28 17:56:25 2006
> >> State : clean, degraded
> >> Active Devices : 2
> >> Working Devices : 2
> >> Failed Devices : 0
> >> Spare Devices : 0
> >> Layout : left-symmetric
> >> Chunk Size : 256K
> >> Number Major Minor RaidDevice State
> >> 0 8 3 0 active sync /dev/sda3
> >> 1 8 19 1 active sync /dev/sdb3
> >> 2 0 0 -1 removed
> >> UUID : b4b161bc:2953b117:9c13c568:47693baa
> >> Events : 0.31307539
> > So mdadm -a needs to be used to add the 3rd device back to md2. Sam's
> > instructions were clear on that. For more information and education use
> > the man page for mdadm.
> > MANAGE MODE
> > Usage: mdadm device options... devices...
> > This usage will allow individual devices in an array to be
> > failed,
> > removed or added. It is possible to perform multiple
> > operations with
> > one command. For example:
> > mdadm /dev/md0 -f /dev/hda1 -r /dev/hda1 -a /dev/hda1
> > will firstly mark /dev/hda1 as faulty in /dev/md0 and will then
> > remove
> > it from the array and finally add it back in as a spare.
> > However only
> > one md array can be affected by a single command.
> > I would do the following that you have not already stated done.
> > 1. create the partition(s) on your new /dev/hdc
> > 2. use mdadm as follows to add it to md2
> > mdadm /dev/md2 -a /dev/sdc3
> > note that I assume your partitions are created and numbered as you have
> > already stated.
> >> What if the next step this is my mail server and I really don't have the
> >> time to reload it.
> >> I have my fstab, partition, mdstat, infomation.
> >> I ran this command sfdisk -d > sdb-parts.dump before a added the new
> >> drive.
> >> Will any of this help?
> > fdisk -l will list the partition information for each drive including
> > start and end cylinders such as this.
> > [root at raptor pgsql]# fdisk -l /dev/hda
> > Disk /dev/hda: 250.0 GB, 250059350016 bytes
> > 255 heads, 63 sectors/track, 30401 cylinders
> > Units = cylinders of 16065 * 512 = 8225280 bytes
> > Device Boot Start End Blocks Id System
> > /dev/hda1 * 1 21 168651 83 Linux
> > /dev/hda2 22 532 4104607+ 83 Linux
> > /dev/hda3 533 721 1518142+ 82 Linux
> > swap
> > /dev/hda4 722 30401 238404600 5 Extended
> > /dev/hda5 722 1359 5124703+ 83 Linux
> > ....
> >>From that you can get not only the size of each partition, but the
> > actual cylinders used and can recreate the table on the new drive
> > appropriately with fdisk.
> >> Like I said before the only raid/partition experience I have is at
> >> initial
> >> installation.
> >> ----- Original Message -----
> >> From: "Jeff Vian" <jvian10 at charter.net>
> >> To: "For users of Fedora Core releases" <fedora-list at redhat.com>
> >> Sent: Friday, July 28, 2006 5:44 PM
> >> Subject: Re: software raid drive failed, please provide step bu step
> >> torebuild
> >> > On Fri, 2006-07-28 at 16:29 -0500, Dan Carl wrote:
> >> > > I have/had a software raid running and sdc drive failed.
> >> > > I got a replacement drive today and installed it.
> >> > > My only experience with set partitions and raids in during initail
> >> setup.
> >> > > I could not fdisk the new drive because i guess it wasn't reconized
> >> > > so I
> >> > > rebooted.
> >> > > Now I can reach the drive via fdisk but I have made more problems now
> >> (no
> >> > > swap now)
> >> > > and I'm not sure the steps to rebuild.
> >> > > Background:
> >> > > I have a FC3 with a software raid.
> >> > > I have 3 SCSI 18gb hard drives
> >> > > If I recall this how I set it up
> >> > > md0 /boot 100MB raid 1 sda, sdb and sdc as spare
> >> > > md1 /swp 768MB raid 0 sda, sdb, sdc
> >> > This toasted your /swp partition.
> >> > Raid 0 is striping, and a single failure toasts the entire device.
> >> >
> >> > You would have been ahead with a non-raid swap, and had 3 separate
> >> > partitions, one on each device, for swap. Failure of one would not
> >> > have
> >> > toasted all.
> >> >
> >> >
> >> > > md2 / ext3 33GB raid 5 sda, sdb, sdc
> >> > >
> >> > > Can someone please help?
> >> > >
> >> >
> >> > --
> >> > fedora-list mailing list
> >> > fedora-list at redhat.com
> >> > To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list
> > --
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