Server Fault Stack Exchange
Server Fault Stack Exchange

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.

Related Tags:

507 questions
2
votes
3 answers

Replacing a drive in a mirrored set (RAID1), how does it know which is "primary"?

Let's say I have a RAID 1 array with two mirrored drives. One goes bad. If I order a spare online and just put it in, the hardware controller will rebuild the array, right? How does it know which drive to mirror? What if the drive I ordered…
THE JOATMON
  • 275
  • 10
  • 31
2
votes
1 answer

Do more mirrors in raid 1 reduce the likelihood of spit-brain failures?

I'm setting up a server, and my predecessor had a habit of setting up multiple RAID 1s with only 2 disks, which eventually resulted in split-brain situations which were difficult to recover from. Since I want the same speed of access, would adding a…
tudor -Reinstate Monica-
  • 1,805
  • 18
  • 36
2
votes
1 answer

Does RAID 1 have a stripe size?

I'm trying to understand RAID levels. I wonder if the notion of a stripe size would make sense for a RAID 1. The drives are more or less byte for byte mirrors of each other. Therefore, the RAID controller can simply read any range of data at will…
boot4life
  • 279
  • 2
  • 5
  • 12
2
votes
3 answers

How do I know if I run hw raid 1?

I created a hw raid 1 using efi. Server Dell PowerEdge T20 with Proxmox The raid controller is 00:1f.2 RAID bus controller: Intel Corporation SATA Controller [RAID mode] (rev 04) root@pve:~# lsblk NAME MAJ:MIN RM SIZE RO…
Binary
  • 21
  • 3
2
votes
2 answers

Unable to remove the software raid-1 array when it is in degraded state

I want to remove the software raid-1 array [ when it is degraded state] configured on LVM in linux system and unable to remove the same. I have even tried using Knoppix Live CD to remove the RAID-1 associated to LVM, but this attempt also failed.…
Sunny
  • 23
  • 1
  • 1
  • 4
2
votes
1 answer

MD, partially grown from RAID1 to RAID5 but was interrupted, disks removed, and now file system is FUBAR

I know that I made some stupid moves to get into this situation, please don't remind me, and don't ask why :-/ I have this Synology DS1515+, with 2x6TB drives in SHR, which means MD RAID1, with LVM on top. After starting a RAID1 to RAID5…
Esben von Buchwald
  • 281
  • 1
  • 4
  • 10
2
votes
0 answers

T110 - Raid 1 - Rebuilding remains at 0% after switching from 1 hd

Dell T 100 Server PERC S 100 Controller Raid 1 with 2 Hds Physical Disks   ID 0: 0 Status OK Name Physical Disk 0: 0 State Online Bus Protocol SATA Media HDD Revision 02.03B05 Failure Predicted No Capacity 232.75GB Used RAID Disk Space…
Aloisio Fraga
  • 21
  • 1
2
votes
1 answer

Change to a different model of RAID controller: SAS 6/iR to PERC 5/i

I've been running a PowerEdge 1950 Generation III with the Dell SAS 6/iR and a RAID 1 array of two SATA SSDs. Since that RAID controller has no battery I wanted to upgrade to the Dell PERC 5/i which does have a battery. I intend to continue to run a…
H2ONaCl
  • 160
  • 8
2
votes
0 answers

How to remove a dmraid RAID1 member (mark as faulty)?

I have RHEL 6.8 installed on a fake Intel RAID1 (Intel Matrix). It's managed by dmraid, consists of sda and sdb and the device name is /dev/mapper/ddf1_4c5349202020202080862682000000004711471100000a28p1 Now I want to write something else to sdb. How…
basin
  • 558
  • 1
  • 5
  • 22
2
votes
0 answers

Creating RAID 1 using mdadm for Root disk in Linux:

I recently found one of our production server (running RHEL7) doesn’t have the root disk mirrored. So, we thought of using one of the spare disks (which has some junk data) for mirroring the root disk using mdraid. I wanted to do it without…
Ram Kumar
  • 73
  • 1
  • 3
  • 8
2
votes
1 answer

How do I format and properly re-add a drive to a RAID-1 array?

I had a failed drive from a RAID-1 array (2 drives) replaced and now need to: Format it. Add it back to the array. My drives are like this: root@s01 [~]# df -h Filesystem Size Used Avail Use% Mounted…
user1227914
  • 147
  • 6
2
votes
1 answer

HP DL360 G6 ssd on raid 1 with smart array p410i write verry slow, how to fix it?

I just bought a HP DL360G6 server with a P410i RAID card with 256mb cache. I am using Windows server 2012 I use Intel 520 series 240GB SSDs in raid 1+0, but the speed is very slow. I checked the speed with crystal disk mark: read =450mb /…
pvd276
  • 29
  • 2
2
votes
1 answer

Should I expect both disks in my RAID1 array to fail at about the same time?

I have an Ubuntu server with two HDD drives in a software RAID1 array. These are identical drives, and I'm assuming they're seeing the same level of read/write activity over their lifetimes (correct me if I'm wrong). Does that mean it's reasonable…
kontextify
  • 189
  • 1
  • 10
2
votes
2 answers

Linux- Convert 2 disk raid1 to raid0

I have a linux server (3.19.0) which has raid setup with md (v3.2.5). / is a raid1 device with 2 disks. There was a mistake when installing this machine, instead we need those 2 disks to be in raid0 configuration. Is there an easy way to change the…
Amandasaurus
  • 31,471
  • 65
  • 192
  • 253
2
votes
1 answer

How to solve intermittent server hangs? Write to (and read from) a disk stops completely

We have a LAMP server for about 6 months. CentOS 7.0 It ran non stop without a restart for the first 3 months then it hang. Then it run for the next 2 months (also non stop without a restart) then it hang again. Then it run for the 14 days then it…
alxsr
  • 21
  • 3
1 2 3
…
33 34