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Questions tagged [raid1]

RAID 1 or Mirrored RAID uses two or more disks that store the same data.

RAID Level 1 or mirrored RAID uses two or more disks that store the same data. One disk is mirrored to the other. Write speeds are the same as using one disk, and read speeds are twice as much.

RAID 1 is used when reliability needs to be higher than normal.

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RAID1: How do I "Fail" a drive that's marked as "removed"?

I have (had) a RAID 1 array (2 disk mirror) and one of the disks, sda, failed. So I've replaced the bad disk with a new one, but seem to be stuck on how to get the second drive back up and running as part of the array. The system is running Ubuntu…
Nick
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Faulty RAID1 disk now shows as foreign

I have a Dell R320 that has two physical drives in a RAID1 array. The RAID controller is a PERC H310 Mini. During routine maintenance I discovered that one of them was showing as faulty. I had to reboot the server and now the previously fault one is…
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Can ZFS mirror a single disk pool automatically?

I'm getting ready to add another server to my home network. I currently have one storage drive for it. I want to add another one to mirror the first drive, but can't purchase the second drive for a couple of weeks to a month. I want to use ZFS on…
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One drive failed in my RAID 1 array, am I safe to replace it without losing data?

We have a server with three disks. Two of them are in RAID 1 defined in BIOS. One of these is showing an error at the bootup screen with the corresponding disk serial code in red. I intend to replace it but I'm very wary of doing something…
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How to auto-start Degraded Software RAID1 under Debian 8.0.0 on boot?

If you remove a component HDD from an array, it drops into a "busy box" shell under "(initramfs)" saying something similar to "cannot mount root device" as the RAID1 array becomes "inactive". It is possible to start it using: (initramfs): mdadm…
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cannot remove faulty device from LVM2 raid1 mirror

One of the three disks went off in my LVM raid1 logical volume. (It was a bad experiment actually). The volume is a pure LVM raid1 one (no, not an LVM mirror), without any mdadm / fakeraid. The problem was realized only at reboot, the device was…
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Linux software raid fails to include one device for one RAID1 array

One of my four Linux software raid arrays drops one of its two devices when I reboot my system. The other three arrays work fine. I am running RAID1 on kernel version 2.6.32-5-amd64. Every time I reboot, /dev/md2 comes up with only one device. I can…
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How do you set up RAID1 with both disks bootable on Debian/Ubuntu?

In Debian 6, new installation, what is the recommended way of setting up a software RAID1 array so that the system is bootable from both disks? I have heard that people that don't know what they are doing may set it up in such a way that the system…
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mdadm: hot remove failed for…

My RAID1 is degraded and I need to replace /dev/sdb. However, I could mark /dev/sdb5 (in /dev/md1) as failed and removed it, but I can't do the same with /dev/sdb1 (/dev/md0 which is mounted on /): root@kes:~# mdadm /dev/md0 --fail /dev/sdb1 mdadm:…
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Would unplugging a drive simulate a drive failure?

I just set up a RAID 1 array, 2 2tb drives mirrored. I am wondering what will happen if one were to fail. Would unplugging one of them be a valid test? I am using the Onboard controller of an asus M4A89TD pro series motherboard. Thanks, Blake
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Boot from software RAID 1 on Windows Server 2008 R2

I have a Windows Server 2008 R2 x64 system with a single hard drive, and I have a spare hard drive of same size/model that's not being used. I was thinking about dropping in the new drive and setting it up as RAID 1 (mirroring) to achieve poor…
Justin Grant
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smart long test - what is the performance impact on busy server?

I have a busy server with a RAID 1 setup. The application (runs in PHP) is very read/write intensive to the database (MariaDB). A cronjob runs smartctl short test every day and checks the output of smartctl -H and mdadm -D. I would like to run a…
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How does Rebuild in host-raid RAID-1 works?

I am testing a Non-Hardware Raid with 3 1TB Disks. I create a RAID-1 Array with my first 2 Disks and installed Windows 7 on the Raid disk that i'd created. I unplugged the first disk SATA cable in RAID Array and reboot the system. When i entered the…
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NAS device claims drive in a RAID is degraded but S.M.A.R.T. says it is fine

I have a Synology DS213 with two 600GB drives in RAID 1. Last night the device reported that my second drive had become degraded and that I should replace it. When I ran a extensive S.M.A.R.T. test the results said that the drive is okay. How can I…
Nathan Villaescusa
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Can you use drives while Raid 1 is rebuilding?

I am going to be rebuilding a raid 1 array. While the rebuild is happening can people still read/write to data in the array?
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