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 ...
1
vote
1answer
203 views

Boot failure with root on MD (RAID1) + LVM: udev event timing

A fresh install of Ubuntu Server 13.10 (x64) is having problems booting from its root volume located in md+lvm. I've kludged a solution for now, but I'd like to understand more about what's going on ...
0
votes
0answers
92 views

What chunks are mismatched in a Linux md array?

After performing a "check" (by writing check to /sys/class/block/md0/md/sync_action) of a md software RAID array with redundancy on Linux, the md subsystem will update the ...
0
votes
1answer
103 views

Is there anything I can do with a software RAID 1 on linux to workaround temporary 'bad' sectors?

Basically I have two identical hard disks that are in perfect working order, they just don't have the vibration tolerance they need for the environment they are in. (I am making an educated guess that ...
1
vote
1answer
86 views

Fresh setup: how to tell mdadm not to bother synchronizing the _data_? Or does it have to?

Two questions: how, if at all, can I tell mdadm that the freshly created array needs no synchronizing because there is no data on it? I.e. basically force it into a state where it assumes that the ...
2
votes
2answers
1k views

mdadm stalls rebuilding a RAID5 array at 99.9%

I recently installed three new disks in my QNAP TS-412 NAS. These three new disks should be combined with the already present disk into a 4 disk RAID5 array, so I started the migration process. ...
1
vote
0answers
106 views

What should I know before I set up RAID 6 on Linux?

I just ordered five 1TB drives to install as a RAID 6 array in a Linux server (keeping the existing 1TB drive as a boot disk). I want to use Linux MD for RAID rather than a RAID card, to avoid ...
2
votes
2answers
4k views

How to stop a Linux LVM volume group?

I am currently dealing with a multiple disk failure on a Linux LVM Volume Group that is backed up by a RAID-5 md device. One disk has been taken out completely and another one is showing a limited ...
5
votes
1answer
863 views

What effect does RAID stripe size have on read-ahead settings?

I'm trying to figure out the correct read-ahead values to set on a RAID10 array, and I'm wondering if the RAID stripe size should factor into my considerations. I've heard conflicting information ...
18
votes
2answers
4k views

Readahead Settings for LVM, Device-Mapper, Software Raid and Block Devices - what wins?

I've been trying to find a straight answer on this one, and it has proved elusive. This question and its answer is close, but does not really give me the specifics I would like. Let's start with ...
7
votes
3answers
3k views

Deciphering continuing mpt2sas syslog messages

Summary I have been getting these cryptic messages in syslog since I installed some new hardware and I can't figure out what the problem is, if it's serious, or what to do about it. They're from the ...
3
votes
3answers
285 views

Can I split one RAID1 partition in two?

I have a linux box with CentOS 6.2 and a RAID1 (2x 2Tb) configuration: /dev/md1 -> / (10G) /dev/md2 -> /home (1.9T) I want to split the md2 in two different partitions, so I can get the ...
4
votes
1answer
128 views

VERY peculiar permission masks, UIDs, GIDs and file names in Linux

I've just booted to find my software RAID 5 in Ubuntu not mounting. When trying to mount it gave me an NFS error (which was confusing). I ran fsck on /dev/md0 and my screen scrolled with fixes for ...
2
votes
1answer
698 views

Backup data from RAID 1 disk out of its server

I'm facing with a pretty easy problem in my opinion. I've extracted a working disk from a RAID1 and I'm looking to copy only data (FS and RAID configuration doesn't matter) into another location ...
2
votes
0answers
319 views

MD Raid can't be assembled

I was running a Raid5 with 3 disks at on my homeserver. But had some problems with the back-plane for the disks. The disks weren't detected reliable. So I replaced the back plane and the disks are now ...
3
votes
2answers
439 views

Linux Software RAID recovery

I am seeing a discrepancy between the output of mdadm --detail and mdadm --examine, and I don't understand why. This output mdadm --detail /dev/md2 /dev/md2: Version : 0.90 Creation ...
2
votes
3answers
650 views

Linux boot: md raid FS not ready (sometimes)

Using Ubuntu 11.04 (latest patched) I have 5 RAID-1 file systems that are automatically assembled during the boot process (Note: none of the system FS /, /usr... are raid, only user FSes). Once in ...
1
vote
1answer
160 views

Erratic write patterns with linux md RAID1

I'm experiencing strange write performance patterns on a RAID1 array of SATA disks. My kernel is vanilla 2.6.37 and my server has 32G RAM. I'm copying a 32G file from an XFS filesystem on a SAS drive ...