0
votes
1answer
28 views

Raid1+0: create stripe over two /dev/mdx on partition or not?

Given that I haven't found a way to define how a Raid10 is created with mdadm, i went the Raid1+0 solution. How to display/define Mirror/Stripping pairs with mdadm mdadm --create /dev/md0 --level=1 ...
4
votes
2answers
281 views

What steps should I take to best attempt to recover a failed software raid5 setup?

My raid has failed, and I'm not sure what the best steps to take are in order to best attempt to recover it. I've got 4 drives in a raid5 configuration. It seems as if one has failed (sde1), but md ...
1
vote
0answers
43 views

Upgrade Raid 1 to Raid 0+1 and bootloader issue

I am trying to convert my current RAID 1 to RAID0+1 and facing issue in installing bootloader - please have a look what i am doing. My current configuration is RAID1(2*10GB): [root@localhost ~]# ...
0
votes
1answer
41 views

Redundancy: LVM+mdadm or LVM internal RAID

The task is to create LVM storage for virtual machine images. So LVM will be used in any case. There are two ways LVM providing redundancy: block mirroring lvcreate -m 1 --mirrorlog mirrored -n ...
1
vote
2answers
55 views

Check badblocks on RAID-0

Without RAID-0, I usually check bad sectors using this command: fsck -yvckfC -E fragcheck /dev/sdX How to check bad sectors when the harddisk was using RAID-0? should I run it for each drive? ...
1
vote
1answer
132 views

mdadm Stuck at rebuilding spare

I have the following Raid configuration, cat /proc/mdstat Personalities : [raid1] [raid6] [raid5] [raid4] md4 : active (auto-read-only) raid5 sda5[0] sdd5[4] sdc5[2] sdb5[1] 1536 blocks ...
0
votes
1answer
74 views

CentOS System Recovery : Overwritten RAID Superblock and porting to new hardware

I have a failed system running on CentOS 6 and would like to attempt recovery of system. One problem it has is the mdadm superblock appears to have some issues, it has all sorts of inconsistent ...
0
votes
0answers
14 views

mdadm - diffference between metadata version

Can anyone tell the difference between all the metadata versions for mdadm? When I try the command mdadm --examine /dev/sda1, I can't seem to find preferred superblocks on version 1.2. Is there a ...
0
votes
0answers
77 views

Software RAID: file system becomes read-only, mdadm fails with SEGFAULT

I have software RAID1 on Ubuntu 10.10 (Linux ubuntu 2.6.35-32-generic-pae). It is dedicated server I control via SSH. Yesterday datacenter people changed one HDD which was crushed. I did not run ...
2
votes
3answers
85 views

awk ignores the record separator I set for the first record

I am trying to change the record separator but awk does not use the record separator I set until the second record and beyond. I get output like this: ARRAY /dev/md4 level=raid1 num-devices=2 ...
0
votes
0answers
35 views

mke2fs.ext3 stripe-width option missing

I'm trying to set up an ext3 filesystem on a RAID 6 array (with 6 disks) on XenServer 6.2 linux. All the help I can find tells me to use the -E stride=xx,stripe-width=xx options. However my version ...
2
votes
1answer
109 views

Linux; Set RAID5 chunk size to 4kB to match FS block size and physical disk sector size

There are many discussions and websites that explain the process of setting up a Linux software RAID with mdadm with the chunk size of a new RAID as 128kBs or 512Kbs. Serverfault is no exception. I ...
0
votes
0answers
38 views

Recovering Linux soft raid 5, disk stays as spare

I got disk failure on my Centos Linux soft raid 5 array (mdadm). I replaced one of the disk and started to rebuild the array. Next time I checked the status, the rebuild was failed. This is the ...
1
vote
0answers
59 views

Why was the replacement drive for failed drive in RAID 1 (linux software raid) was added as a spare?

I have a two drive linux software raid 1 for a server. There are two raid devices. (Boot (md0) & OS (md1)) Last week one of the drives failed so i ordered a new one. Today i shutdown the server, ...
1
vote
1answer
122 views

Linux Server OS on LVM on Software RAID: Best Practices and Considerations

I am preparing for a minimal Ubuntu Server 12.04 LTS that will simply run libvirt/KVM to host a handful of Ubuntu Server 12.04 LTS guests. On my KVM host I created a RAID 1 comprised of two physical ...
1
vote
0answers
609 views

How to recover an mdadm array on Synology NAS with drive in “E” state?

Synology has a customized version the md driver and mdadm toolsets that adds a 'DriveError' flag to the rdev->flags structure in the kernel. Net effect - if you are unfortunate enough to get a array ...
3
votes
3answers
120 views

Linux MD RAID resilience in situations with unpredictable power

If you were given a situation where you MUST use RAID for reasons outside of your control and the server with the RAID may not be on a battery backup and the building is prone to power loss, what are ...
0
votes
2answers
116 views

Path of md device wrong after reboot

I have to set up a software raid (level1) on a Ubuntu server 12.04. It should serve files in the network via Samba. The server has the following disks: 250gb Sata hdd (Ubuntu is installed on that ...
0
votes
2answers
74 views

Linux: How to restore data from failed disk from software raid

I have a disk failure in software RAID (1) and marked a broken disk as fault (mdadm --manage /dev/md0 --fail /dev/sda1). Unfortunately I destroyed data on the second disk after that. Is it possible to ...
0
votes
0answers
75 views

Replace a slowly dying drive in Linux software raid5

I have the same problem as in Can I "atomically" swap a raid5 drive in Linux software raid? i.e. a Linux software raid with 3 RAID5 disks where one disk is showing smart errors but isn't ...
-1
votes
2answers
77 views

What is the correct way to create new raid5 in Linux?

I added some new disks, and tried to create new array, using: mdadm --create /dev/md/2 --level=5 -x 0 --raid-devices=4/dev/sd{a,b,c,g}2 It creates the array, but after reboot - it's gone. What ...
0
votes
2answers
139 views

Convert Raid 1 to Raid 10 with no new disks

I just got a new remote root-access server with 2 1TB disks in a Raid 1 configuration, running Debian (squeeze). Before installing my stuff on it, I'd like to switch to Raid 10 if I can. All the ...
0
votes
1answer
79 views

Does the built-in CentOS software RAID distribute writes?

Will I see a write performance increase going from single disk to CentOS Software RAID10? Any industry estimates on the % increase?
2
votes
2answers
256 views

Remake SW RAID1 from a new HDD and an old HDD with bad blocks

I have a SW RAID1 and I just replaced /dev/sda with a new HDD as the old one failed. Now, upon trying to recreate the RAID array I discovered that the "good" HDD (/dev/sdb) has bad blocks with prevent ...
0
votes
0answers
136 views

Partition missing on ephemeral storage on ec2 after reboot (not restart)

I had a software RAID 0 on an ec2 instance. I needed to make some changes so I stopped the RAID, unmounted it, and rebooted the instance. What's troubling is, I don't see a partition for one of the ...
1
vote
1answer
824 views

Linux RAID5 Optimal Chunk Size

I bring up, yet again, the ever-present question of how to best optimize disk structures. In my organization, we have a 14TB Linux software RAID array dedicated to storing backups made using Symantec ...
7
votes
2answers
172 views

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 ...
4
votes
2answers
942 views

Major issues with fsck of 10TB ext3 RAID 6 (memory allocation failed, etc.)

I recently added a 7th 2TB drive to a linux md software RAID 6 setup. After md finished reshaping the array from 6 to 7 drives (from 8 to 10TB), I was still able to mount the file system without ...
2
votes
1answer
150 views

Performance of Linux software raid-1 across SSD and HDD (partitions)

How does Linux software raid-1 work across disks of dissimilar performance. Would a raid-1 across ssd and hdd partitions give me a mirror of the ssd contents while not impacting the read speed? I ...
5
votes
1answer
346 views

100% packets dropped on first RX queue on 3/5 raid6 iSCSI NAS devices using intel igb (resolved)

Edit : The issue is resolved. The Queues in question have been used for Flow Control Packets. Why the igb driver propagated FC packets up to have them dropped (and counted) is another question. But ...
1
vote
1answer
652 views

How to get notified of mdadm RAID problems?

I am running Ubuntu 12.04 LTS. Yesterday I found a message in my mailbox saying that my server was shut down. I proceeded to reboot the system, but it didn't come up after many minutes, and I didn't ...
5
votes
1answer
2k views

Implementing Linux fstrim on SSD with software md-raid

I'm currently building a new Ubuntu 13.04 server with 2 256GB SSDs in a raid mirror to run a MariaDB instance. We typically place LVM on top of dm-crypt encryption on top of an md raid 1 array, but ...
0
votes
2answers
547 views

How to mount parition in from a working driver in RAID1

One of hard drives in array is dead, I'm unsure if it's raid0 or raid1, what I'm trying to achieve is mount the working drive and make a backup of what's left. If I mount /dev/md127 then I can see ...
5
votes
2answers
322 views

mdadm: Which disk is being rebuilt?

I noticed my software RAID1 degraded, and wanted to figure out which of the two disks in the array is being rebuilt/re-synced since they both show as being up. I am hoping someone can shed some light ...
0
votes
1answer
341 views

mdadm - raid device name changed on reboot

I'm not sure why, but after I restarted my ec2 instance, /dev/md0 didn't start as it normally would. after I saw what's available in /dev/md*, instead of seeing /dev/md0, there is a device there named ...
0
votes
1answer
142 views

Mirror two software RAID volumes

I have two software RAID volumes of differing speed and reliability on Ubuntu 12.10. I want to mirror the contents of the faster, but less reliable /dev/md0 to /dev/md1. My plan was to build a ...
2
votes
1answer
2k views

High server load - [jbd2/md1-8] using 99.99% IO

I've been having spike in load over the last week. This usually occurs once or twice a day. I've managed to identify from iotop that [jbd2/md1-8] is using 99.99 % IO. During the high load times there ...
0
votes
1answer
630 views

Fedora. Properly configure RAID1. Raid has name /md127

I have RAID1 with 2 3TB disks. The general problem as I see is that for some reason this array have some problems with naming. It has md/19 md/19_0 and md127 My goal is to make this 3TB Raid1 ...
3
votes
1answer
2k views

Linux file system cache: Move data from Dirty to Writeback

My software RAID can write 800 MB/s sustained. I see that happening when cat /proc/meminfo |grep Writeback: returns > 2 GB. However, most of the time the writeback is round 0.5 GB which gives a ...
2
votes
1answer
128 views

Linux: md Software RAID array out of sync

We had a CentOS server report this software RAID issue via /etc/cron.weekly/99-raid-check WARNING: mismatch_cnt is not 0 on /dev/md2
0
votes
1answer
219 views

Linux RAID10 hit bad disk while re-syncing. Is it hosed?

I have a Linux software RAID10 device on md0. It's made up of 4 1TB disks sd[abcd]. Yesterday Smart emailed me to say a disk was going bad (seek errors going up and reallocated sectors). I rebooted ...
-1
votes
2answers
139 views

How do RAID 0 Offers improved i/0? [duplicate]

Possible Duplicate: What are the different widely used RAID levels and when should I consider them? I wonder how RAID 0 offers better i/o. If i am not wrong in RAID 0 data gets split and ...
1
vote
1answer
64 views

Adding Raid 1 to Raid 0 on Linux

I have a system already configured with raid 1 with 2 disks: /dev/md1 918347072 249416692 621528596 29% /var /dev/md0 9920532 160640 9247828 2% /tmp # cat ...
3
votes
1answer
445 views

Removing a device in “removed” state from Linux software RAID array

My workstation has two disks(/dev/sd[ab]), both with similar partitioning. /dev/sdb failed, and cat /proc/mdstat stopped showing the second sdb partition. I ran mdadm --fail and mdadm --remove for ...
2
votes
1answer
198 views

How do I find out which disk in a multi-disk mdadm RAID1 triggered a rebuild?

I'm using mdadm for several RAID1 mirrors. md7 is an N-way mirror consisting of 3 spinning disks (all flagged write-mostly) and an SSD: md7 : active raid1 sdd1[0] sde5[3](W) sdf5[4](W) sdc1[1](W) ...
3
votes
2answers
177 views

Linux software RAID - partition first?

I have two identical drives that I intend to mirror in in the interest of data safety. These are data-only drives, not a primary OS drive. In such a system, is it better to create single partition ...
5
votes
2answers
385 views

Linux software RAID6: rebuild slow

I am trying to find the bottleneck in the rebuilding of a software raid6. ## Pause rebuilding when measuring raw I/O performance # echo 1 > /proc/sys/dev/raid/speed_limit_min # echo 1 > ...
0
votes
1answer
321 views

Raid 10 - Very slow [closed]

I have Software Raid 10 setup, it has been working great a few months. When I did a quick HD speed test: dd if=/dev/zero of=test bs=64k count=16k conv=fdatasync It is taking forever and I had to ...
1
vote
0answers
207 views

Reusing slot numbers in Linux software RAID arrays

When a hard disk drive in one of my Linux machines failed, I took the opportunity to migrate from RAID5 to a 6-disk software RAID6 array. At the time of the migration I did not have all 6 drives - ...
1
vote
1answer
422 views

Controlling mdadm faulty disk rebuild order in RAID 10 array

I have a Linux mdadm RAID 10 array comprising of 6 (SATA) disks configured with n2 copies. While pulling out one disk, another one in another mirror pair failed. Leaving me with: $ cat /proc/mdstat ...