Software :: Converting From RAID1 To A Single Disk?
Apr 5, 2011
I recently had an issue where one of my RAID1 configured drives died on a Debian box. By die, I mean after post, I am presented with a black screen and flashing cursor, nothing more. I booted into a knoppix shell and did:
mdadm --assemble /dev/md0 --run -u <UUID of the only working drive> /dev/sda1
I could then 'mount /dev/sda1 /mnt/' and see all the contents as I should be able to. However, I cannot boot from this device by itself for some reason. I have reinstalled grub 'grub-install --recheck --rootdirectory=/mnt /dev/sda1' #something like that, can't remember the exact --rootdirectory command without the switch. I restarted, with the failed drive unplugged, and again, I'm faced with the black screen, flashing cursor.
View 1 Replies
ADVERTISEMENT
May 5, 2010
I have an Ubuntu Server on (8.10) running under Citrix XenServer (though that shouldn't make a difference).
I installed on a single disk:
xvda1 - 200 MB - /boot
xvda2 - 9.8 GB - LVM (ubuntu-base)
The LVM is:
swap - 1.0 GB
root - 8.8 GB - /
I have successfully gotten this converted to RAID1 by adding a new drive (xvdb) and following the Debian howtoforge article [URL]
What I have not been able to do, is get grub working properly.
If I fail xvdb and reboot the system, everything comes up and I can reboot and run.
If I fail xvda and reboot the system, XenServer gives me a bootloader error. i.e.: no grub
If someone has done this, can they tell me what grub commands to run to get a successful boot of the primary disk fails?
View 1 Replies
View Related
May 3, 2011
im on 10.10(desktop) and mdadm was v2.8.1 from 2008, very out of date so i tried 3.2.1 -> no change. mdadm raid1 read speeds are the same as single disk. note i used the tests in the disk utility benchmarking tool at first --these showed raid 5 atleast to be much better but when i tried dd reads raid5 dropped off with larger data to almost the same (slow) speed as raid1. compare:
[code]....
using two partitions will be enough to show raid1 performs at single disk speed. I dont really want to use a 4 disk raid0 just to get the read speed i should be able to get with raid1 as i dont really care about the size loss. I would of course use raid10 but i have found this suffers from the same problem (achieve same read speed as 2 disk stripe). So whilst im shocked others aren't reporting this, unless there is some obscure reason why my system would give these results i think raid1 in not behaving as it should.
View 6 Replies
View Related
Oct 27, 2010
I have a hypothetical situation in which I installed my operating system using a RAID1 mirror. At some point I decided that this setup was overkill, my machine isn't system critical, I value doubling my storage space more than speedy recovery, I'm doing routine backups, etc...
Short of backing up my system volume and repartitioning, or otherwise starting over, is there a way I can reconfigure my RAID1 array to only expect one disk so that mdadm no longer reports a Degraded state?
View 3 Replies
View Related
Oct 16, 2009
my Fedora 11 system is not starting anylonger. It stops with the message:
Code:
VFS: Can't find ext4 filesystem on dev dm-0
The system told me since a while, that a lot of the sectors of one disk of the (software) RAID compound are failed already. So tried to disconnect each of the disks and start them separately. Unfortunaltly this is not working (for one its is not working at all, the other wents the same far as with both), when I tried to recover the system with the Fedora DVD, it said no distribution found. I am quite new and do not know so much about linux system, so i do not know what further information you could need. Maybe it can be important, that both disks are encryped (the system wents so far, that I can type in the password).
View 2 Replies
View Related
Aug 1, 2010
I had done a new lucid install to a 1 TB RAID 1 array using the alternate CD a few weeks back. I messed up that system trying to some hardware working that lucid doesn't have drivers for yet, so I gave up on it and reinstalled to a single 80 GB disk that I now want to move over to the RAID array.
I moved all of the existing files on the array to a single folder, then copied all of the folders from the 80 GB disk over to the array with permissions and symlinks (minus the contents of /proc and /sys, which I created empty).
These are the commands I used:
Quote:
p -a -d -R -v -t /media/raid_array /b*
cp -a -d -R -v -t /media/raid_array /d*
cp -a -d -R -v -t /media/raid_array /e*
cp -a -d -R -v -t /media/raid_array /h*
[Code]....
I tried to change fstab to use the 689a... for root, but when I try to boot, it's still trying to open /dev/disk/by-uuid/412d...
So then I booted from the single disk again and chrooted into the array, then ran update-initramfs -u. I got 3 "grep: /proc/modules: No such file or directory" errors, and "cat: /proc/cmdline: No such file or directory"- so I created directory /proc/modules, created an empty file /proc/cmdline, and ran the initramfs update again. Then I tried to shut down, which hung (probably because I was doing all of this from a terminal window in Gnome), so I killed the power after a couple of minutes.
It's still trying to use /dev/disk/by-uuid/412d... to boot.
What am I missing? I assume I just have to change the UUID to mount as root, but I don't know how.
View 2 Replies
View Related
Jun 9, 2010
I have two 80 GB IDE hard disk. I have create raid1 partition in both drive using [URL] ink. raid is working fine. But i have copy some data on one hard disk (md0) but this data is not autometically copy in second hard disk(md1). I want when data is write on one hard disk, this data autometically write in second hard disk.
View 11 Replies
View Related
Dec 7, 2010
Just finished installing F14 with RAID1 setup for 2 hdd (SATA''s). Entire drives are mirrored, including SWAP. As I had done in the past, I was planning on installing grub on MBR of 2nd hdd. In prep for this I did the following to locate the grub setup files:
grub> find /grub/stage1
find /grub/stage1
(hd0,1)
[code]....
I was surprised, expected to get (hd0,0) & (hd1,0), not (hd0,1) & (hd1,1)
running "fdisk -l" I get:
Disk /dev/sda: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders, total 234441648 sectors
Units = sectors of 1 * 512 = 512 bytes
[code]....
MBR is the first 512 bytes of the drive. Each partition has a boot sector. In my case grub stage 1 is on 2nd partition of sda & 2nd partition of sdb. What i dont understand is how grub stage 1 can be on sda2 & sdb2, since I am assuming that sda1 & sdb1 would be the first partitions of the drives & therefore contain the MBR's. Maybe this might be because sda1 & sdb1 are SWAP partitions?
View 5 Replies
View Related
Jun 8, 2011
Is there a difference between raid1 and ordinary hard disk?
View 11 Replies
View Related
Mar 12, 2011
I've read many of the postings on ICH10R and grub but none seem to give me the info I need. Here's the situation: I've got an existing server on which I was running my RAID1 pair boot/root drive on an LSI based RAID chip; however there are system design issues I won't bore you with that mean I need to shift this RAID pair to the fakeraid (which happens to most reliably come up sda, etc). So far I've been able to configure the fakeraid pair as 'Adaptec' and build the RAID1 mirror with new drives; it shows up just fine in the BIOS where I want it.
Using a pre-prepared 'rescue' disk with lots of space, I dd'd the partitions from the old RAID device; then I rewired things, rebooted, fired up dmraid -ay and got the /dev/mapper/ddf1_SYS device. Using cfdisk, I set up three extended partitions to match the ones on the old RAID; mounted them; loopback mounted the images of the old partitions; then used rsync -aHAX to dup the system and home to the new RAID1 partitions. I then edited the /etc/fstab to change the UUID's; likewise the grub/menu.list (This is an older system that does not have the horror that is grub2 installed) I've taken a look at the existing initrd and believe it is all set up to deal with dmraid at boot. So that leaves only the grub install. Paranoid that I am, I tried to deal with this:
dmraid -ay
mount /dev/mapper/ddf1_SYS5 /newsys
cd /newsys
[code]....
and I get messages about 'does not have any corresponding BIOS drive'. I tried editing grub/device.conf, tried --recheck and any thing else I could think of, to no avail. I have not tried dd'ing an mbr to sector 0 yet as I am not really sure whether that will kill info set up by the fakeraid in the BIOS. I might also add that the two constituent drives show up as /dev/sda and /dev/sdb and trying to use either of those directly results in the same error messages from grub. Obviously this sort of thing is in the category of 'kids don't try this at home', but I have more than once manually put a unix disk together one file at a time, so much of the magic is not new to me.
View 2 Replies
View Related
Jul 22, 2011
I have SLES10-SP3 running on an Intel SR1600URHS board with 3 hot-swap SATA disks configured using mdadm as Raid1 with hot spare. If I pull one of the active disks, all file i/o will stop for about 2.5 minutes after which it will start again and the raid array will be rebuilt using the spare disk. Is there any way I can reduce this 2.5 minutes of inactivity? I've tried setting /sys/block/sdX/device/timeout and /sys/block/sdX/device/retries to 1 for all disks, but this hasn't made any difference. The output from messages is:
12:11:56: ata2.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x2 frozen
12:11:56: ata2.00: cmd ea/00:00:00:00:00/00:00:00:00:00/a0 tag 0 cdb 0x1e data 0
12:11:56: res 40/00:03:00:00:20/00:00:00:00:00/b0 Emask 0x4 (timeout)
[code]....
View 1 Replies
View Related
Feb 1, 2011
We have had a hardisk crash in our RAID1 webhosting server running CentOS5 and Plesk. We first realized something was wrong when our main site didn't load but showed MySQL errors. We then found out that the system was in read-only state. Something that also happened the day before yesterday, but we could fix with a FSCK. Then the system worked well til around 18 hours later when it crashed with the same sympoms. So, we rebooted the server and wanted to do a filesystem check again. But the HDD wouldnt even load. It was gone. Unfortunatelly it was not realized that the second disk in the system was also not working any more for some time now. Fortunatelly we had our main site backed up externally though. So we could re-install a fresh box and mounted the two drives to the system. We checked the harddisk. One is practically empty (the older one), the other has almost only files in 'lost + found' but these are all "numbered", no real filenames or so.
View 2 Replies
View Related
Jul 21, 2010
Could anyone give the steps for converting a logical volume to a raw disk to mount Oracle ASM Instance on it?
View 2 Replies
View Related
Jan 25, 2010
I'm trying to figure out if a box is running just a single sda disk. or if it actually has hardware RAID setup and Linux just sees this virtual sda disk which is actually composed of several drives hidden behind the card. for software raid i know that doing mount command would show something like
/home mounted on /dev/mapper/ddfadasdf34234234234
and for nvidia card it would say something like
/home mounted on /dev/mapper/nvidia_34324234234
but in my case i just see /dev/sda1 mounted on /home
cat /proc/scsci/scsi however see several drives being on the system, dmesg shows the same. But I only see this one drive when doing mount. So basically I have conflicting information. What would be the sure way to figure out if i do have a raid array and if so what raid level I'm running.
View 3 Replies
View Related
Mar 25, 2010
Can RAID be implemented on a single hard disk ? If yes, plz give a link for it.
View 2 Replies
View Related
Jan 3, 2010
I am running Ubuntu 9.10 x64 on a relatively old laptop and I find Grub is taking about 20 seconds to initially load before booting the system. The laptop only has a single 120GB hard drive, and I chose the "use entire disk" option when installing, so I do not have any fancy partitioning scheme.When the system boots I get the "LOADING GRUB" text displayed and then shortly after it just shows the flashing cursor with no text, and stays there for about 20 seconds. After that it finally starts loading the system.All the searching I have done only turned up solutions relevant to people with multiple hard drives. This was not an issue on Grub 1.
View 1 Replies
View Related
Feb 2, 2010
Recently, one the SMART utility said that one of the drives had failed and another drive was about to fail. I downed the box and hooked them up to my windows machine to run sea tools on them (They are all seagate drives). Sea Tools said that the drives were fine, while ubuntu said they were failing/dead. Yesterday I decided to try to fix one of the drives in the raid. I turned the server off, took the failed drive out, and restarted. Of course the raid didn't work because only 2 of the 3 drives were there, however it had been working w/ only 2 of the 3 drives for a couple months now (I'm a lazy college student). I turned it back off and back on with the drive there just to see if I could get the raid up again, but I havn't been able to get it to go. So far I've tried:
Code:
mdadm --assemble /dev/md0 /dev/sd[b,c,d]
mdadm: no recogniseable superblock on /dev/sdb
mdadm: /dev/sdb has no superblock - assembly aborted
[code]....
I'm looking for a way to trick the raid into working with just 2 drives until I can warranty the seagate and buy an external 1.5 TB drive to use as another backup. how to remove the bad drive from the array and replace it with a fresh drive, without data loss.
View 3 Replies
View Related
Oct 27, 2009
If you want a full run down as to WHY I want to do this, read here: webhostingtalk.com/showthread.php?t=899909Basically, my ISP could not get my server running stable on a simple raid 1 (or raid 5) so what it came down to was having them install my system on a single disk. I don't exactly like this, main reason being, if the system (or HDD) crashes, I'll end up with another several hours of down time..
View 1 Replies
View Related
Jun 24, 2009
I dont know if this is possible or not but here what I would like to do. I have 6 linux server and each has 100GB disk space. All of these 6 box are compute nodes and space are not used really. However, If I can combine 6 servershard disk that will in total 6*100GB gives you quite a bigger space. Is there any tool or ways to mount these drive in one volume instead of mounting individually ?
View 2 Replies
View Related
Jul 1, 2010
I need to install a voice recording application on a server.My problem is that I have four hard disks with 150 GB storage space each. So I have 150*4 = 600 GB Storage available as whole .I need all four hard drives (600 GB ) as single volume to store and retrieve recording .
View 1 Replies
View Related
Aug 19, 2010
For portability reasons; I am building a standalone kickstart ISO; based of Cent5.2. I am to the point where I can load my ks file (linux ks=cdrom:/ks.cfg), it reads it fine; and performs the install as I want.
Where I am having a problem; is a good way to have the install use upgraded RPM's, not the base; specifically a kernel with a few needed tweaks in it; which is packaged in an rpm.
I attempted to place my kernel rpm's into the CentOS directory and rerun creatrepo; but I simply managed to corrupt the base repo on the install media.
View 2 Replies
View Related
Jul 7, 2011
I need to copy data from a single HD, which used to be part of a Linux RAID 1. I've googled around, but can't find any clue how to mount partitions from this single HD.
Background: The HD comes from a linux based NAS box Synology DS207+. The NAS uses ext3 as filesystem. Both NAS disks are fine, but the other NAS hardware is dead and not worth repairing or replacing.
View 1 Replies
View Related
May 18, 2010
Was wondering if it's possible to set up a single disk with btrfs and then later on convert it to a 'mirrored' array?
View 1 Replies
View Related
Jun 16, 2011
Oooookay, so basically the idea I have is that I would like to boot Windows XP over an AoE connection. This is no issue, however the problem comes when I want to have a single, read-only image as the base image and want to be able to boot multiple computers off this image.Licensing issues aside (let's assume that this complies with all licensing issues, or we can think of it as just a conceptual "how could we do this"), the basic issues are thus:Each boot of Windows will require a writable AoE device...The original disk image must be read-only to avoid changes in 1 boot affecting all boots(As far as I know) The AoE device must be a disk image, or some block device rather than a mounted file system (if this is not so, aufs could be used)So the long and the short of this, from what I can tell is that we need a read only device that we can write to.
At the end of a session, the changes to the device will be discarded, so these can be thought of as simple temporary sessions. This means that there is little concern with having changes to the original read-only image effecting the modifications to the "duplicate" images.
I would like to avoid duplicating the image for each instance, however if no solution can be reached then this could be a possibility (every boot, we can copy the image, give the fresh image to the new boot and remove when done)Optimally, changes to the filesystem will be written to a different filesystem (much like what aufs does, however as stated earlier, afaik aufs only deals with 2 mounted file systems, whereas we need the end result to be an image or block device)Sorry if I havn't explained this particularly well, however I've been trying to think of solutions, caveats and generally how to define the problem as I was writing. If you think that this idea is ridiculous because software x handles the problem better, I'd be very pleased to hear about it, but the basic requirement of temporary, network bootable windows xp sessions still applies.
View 3 Replies
View Related
Sep 1, 2009
Nothing is working,[URL] My bootable pendrive is not seen by grub. The tab in grub, e, gives my 3 partitions only
[URL]
View 2 Replies
View Related
Jun 10, 2011
Relational databases usually have their data over in /var/lib/something. Users are in /home (with data in /var/www). How can I apply a single total disk space quota across all of these independent software systems (file systems, RDBMS, etc.)?
P.S. There's a bet going on around me as to just how awesome SU is. Let's see what you've got.
View 1 Replies
View Related
Oct 13, 2010
I have question about the UNIX sockets. my goal is to connect multiple sockets from a single client to a single server and keep them open...I'm not sure if that is possible to create or not. Do you have any suggestion or an example of code?
View 1 Replies
View Related
Apr 1, 2010
I'm building a NAS with xubuntu and I've put 2x1,5TB disks in RAID1 with mdadm. My question is really straightforward: do you have any advice for some special tuning/configuration for the RAID setup? Somewhere I read that I should disable disk caching, but I would like to have some more opinions.
View 2 Replies
View Related
Dec 10, 2010
I am trying to boot my F13 server that has 3 partitions (sda2,sdb2,sdc2) configured as RAID1 (md0), vg00 is on md0 and / is on vg00/lvol00 and boot is on /dev/sda1, sda3,sdb3 and sdc3 contain other non-OS data and I get the following errors
dracut scanning devices sda3,sdb3,sdc3 for LVM logical volumes vg00/lvol00 vg00/lvol01
.
dracut: Volume group "vg00" not found
dracut: Skipping volume group vg00
dracut: Autoassembling MD Raid
No root device round
and then everything stops
If I go in with rdshell and type in -
[Code]...
Ok I managed to solve it. When I originally installed F13 I had 2 partitions in md0 and later on I added /dev/sdc2 to make it a 3 partition Raid 1 array. My thinking was seeing that I had the extra space it wouldn't hurt to use it as another mirror. One month later after I booted the server I have found out it did hurt. I removed the 3rd partition and now it's fine again. I wonder though if it would be possible though to use that 3rd partition.
View 1 Replies
View Related
Dec 29, 2010
I have just upgraded to Fedora 14 from an older version. I now have problems mounting my RAID1 array, which was operating correctly until now. This is a software RAID which was initially built under Fedora 10.The array is md0, and is made of 2 SATA drives (sdc and sdd) which have only one partition. The underlying filesystem is NTFS. The array is assembled correctly and active, as reported by /proc/mdstat and mdadm -D.When I try to mount the array, I get this:
Code:
[root@Goofy ~]# mount /dev/md0 /mnt/raid
mount: you must specify the filesystem type
[code].....
View 4 Replies
View Related
