raid - How to reassemble a RAID5 array after power outage while re-adding

So, here is the history:After a power outage, my RAID5 wouldn't work becaus 3 drives needed to be re-added. I launched mdadm --manage --re-add /dev/md0 /dev/sd[abd]1 as I always do after power issues.This usually takes 2 seconds but this time, it was running for a long time. And unfortunately, another power outage happened.The current RAID5 won't reassemble:# mdadm --examine /dev/sd*1/dev/sda1: Magic : a92b4efc Version : 1.2 Feature Map : 0x8b Array UUID : 0993cb6a:f3459891:b7cdab4b:6ea12dfe Name : abydos:0 (lo...Read more

MDADM Raid Keeps Failing - Configuration or Hardware?

I am having no luck at all setting up Raid using MDADM. At this point I'm suspecting it's my hardware. Shortly after the initial set up and both during and following a successful syncing process, drives will be marked as Failed and Removed from the array. I've tried both using the RAW drive method and the Partition method. Using the partition method I've tried both the full capacity as well as a smaller partition size (-100MB of capacity at start of partition). I've concluded from the many posts I've found that adding partitioned drives wit...Read more

raid - Can I recover a ZFS pool if the OS HDD died without exporting ZFS?

Unfortunately my main OS HDD died. I had a 4TB ZFS pool configured over 3 drives, as below:120GB HDD - Ubuntu 10.12. The ZFS pool was setup from this hdd.1TB HDD - part of the pool1TB HDD - part of the pool2TB HDD - part of the poolThe main HDD is unrecoverable. Is ZFS clever enough to recognize the existing pool if I plug those 3 HDDs into a new machine? I already have a new HDD which I'll install Ubuntu on again.Is a simple zfs import going to suffice? If I need to rebuild the pool, can I maintain all of the data? As you can tell, I'm not a...Read more

raid - RAID1 replacing drive questions

I got some questions about RAID1 behavior.1. When HDD1 and HDD2 are not in sync, say I purposely add 1 more file to HDD1 when HDD2 is not present, what will RAID1 do to get them in sync again?Say HDD1 and HDD2 are setup as RAID1 with Windows 7 OS installed. Now I have a single HDD3 with Windows 10 OS installed. What happens when I replace HDD1 with HDD3? What happens when I replace HDD2 with HDD3? Who will rebuild who in both cases.Say HDD1 has Windows 7 and HDD2 has Windows 10 (they are not RAID yet). Now I setup both of them RAID1, who will r...Read more

raid - IO i.e read write operations are stopped some of the drives verified using iostat

I am running IOs on 105 hard drives inserted in my RAID Box. I have stared FIO to run IOs on my all disks and observing read writes using iostat. But after some time I found some drives showing me read write per second rate is 0. I don't understand if its really stops or its still running. some drives IO operations as below.sdbe 61.50 46288.00 20276.00 92576 40552sdbf 63.00 46580.00 20824.00 93160 41648sdbg 59.50 45192.00 19728.00 90384 39456sdbh ...Read more

raid - will megacli on lsi 2108 controller destroy data on drive that is created as RAID0

I have a bunch of disks connected to an LSI 2108 SAS controller on a Centos BOX, i need to salvage all the data from those drives. The disk has been used directly on some other linux box and was not in part of any RAID group. i am afraid my controller is not able to JBOD aka Pass through. Will the data be corrupted if i will connect the drive as single RAID0 drive?========================================================= Versions ================Product Name : LSI MegaRAID SAS 9261-8iSerial No : SV02808690FW...Read more

raid - What causes Silent Data Corruption on HDDs?

Some landmark studies a number of years ago now showed that silent corruption in large datasets was far more widespread than previously anticipated (and today I guess you'd say it's more than commonly realized). Assuming that the application and OS wrote a sector and had time to let everything flush, with no crash or abnormal shutdown, or software bugs that would command wrong data to be saved.Later, a sector is read back in, and there is no read error from the HDD. But it contains the wrong data.Since HDD data encoding contains error correct...Read more

raid - ext4 inode data location math?

I am trying to restore data from a RAID 5 with bad superblocks. I've written a tool in g++ that lets me dump data from all 3 drives simultaneously and will create data from a missing drive if there is one. which there isn't. I do know one drive is not 100% synced so that feature may come in useful later. It also has an ASCII search function which helps in finding directories but potentially takes two days to complete searching through 3TB of data.Anyway the question is how do I calculate the block I want to dump from the inode number? The inode...Read more

disk - Drive failure(s) in linux mdadm raid array. Help!

It looks like my system is suffering from some sort of catastrophic failure, and I'm panicking at the moment, not sure what to do.I had a 3 drive raid 10 array. I noticed this morning that I was having trouble accessing the array (all my photos are on there). I checked mdadm and it said that one drive was dropped from the array (drive 2). I think this may have been because the computer was shutdown accidentally (there was a blackout), and the drive was kicked as a result. I tried adding the drive back, and that worked. Then I checked the p...Read more

raid1 - How to rebuild a two drive raid 1 array on Linux?

I need to rebuild a two drive (160x2) raid 1 (mirror) array. It was an Intel raid from a 7 year old Dell computer (Windows). Both drives are assumed to be functioning. The raid was created with an on-board motherboard raid program. It's been quite a while since I had to rebuild a raid, and the last time it was a raid 5 that had been created on Slackware. Where do I get started? I'm putting them in my personal machine and I'm guessing that Linux is going to be the tool to get this done....Read more

raid - ZFS Mirror over one large disk and a RAID0 of two small disks

You have: two disks of size X and one of size 2X.You want: zpool with mirror-like redundancy of size 2XConcatenation of the two X drives is straightforward with ZFS. But I found no way to mirror the resulting vdev (size 2X) with another 2X disk with ZFS's in-house means.These (more or less unelegant) solutions came to my mind:Use OS tools (mdadm for Linux, gstripe for FreeBSD) to connect the two X drives to a single physical device that can be mirrored with the 2X one. But I am uneasy with the additional complexity, platform-dependence, and los...Read more

mdadm - Can I create a software RAID 1 with one device

I have a single disk that I want to create a mirror of; let's call this disk sda. I have just bought another identically-sized disk, which we can call sdb. sda and sdb have one partition called sda1 and sdb1 respectively.When creating a raid, I don't want to wipe my sda clean and start again, I just want it to start mirroring with sdb. My train of thought was to do:mdadm --create --verbose /dev/md0 --level=mirror --raid-devices=1 /dev/sda1... to create the array without sdb disk, then run something like (I'm thinking the following command out l...Read more

raid - mdadm RAID5 with bad sectors and bad blocks

I have a 4 disk RAID5 setup with mdadm in Ubuntu 16.04.sdb : goodsdc : 8 bad sectors according to SMART, 8 pending, 4 reported errorssdd : bad blocks present according to mdadm --examinesde : goodI was naive and assumed the system would notify me of a disk failure. Since the last update according to "mdadm --examine /dev/sdd" was November, I know that's when it was removed from the RAID. For 7 months, I've been unwittingly running in degraded mode. Until this past weekend, when it marked sdc as faulty and my RAID became inactive due to insuf...Read more

raid - LUKS partition destroyed, can't recover

so I did a very stupid thing (fortunately not on purpose). I had missing superblocks on a ext4 partition, which was encrypted by luks and sitting on an mdadm raid 5. For some reason I ran mke2fs on it (/dev/md1) and managed to ignore the warning that this is a Luks partition. I stopped after it wrote a few inodes. Now the system will not detection it as a luks partition anymore and luksOpen, etc. fails, which, I guess, makes sense. Currently testdisk is running a deepsearch but I have little hopes.Anything that comes to mind? The situation is n...Read more

raid - BTRFS has become unmanageable

I'm struggling with a btrfs RAID0 filesystem.It's expanded on 4 disks but i need to remove one of those disks.This is the current status of the filesystem:[root@osgiliath detlev]# btrfs fi show /mnt/Data/Label: 'Data' uuid: 4c15fe81-ca58-4ac5-adf7-bdde245496f0 Total devices 4 FS bytes used 1.26TiB devid 1 size 2.68TiB used 612.55GiB path /dev/sdc2 devid 2 size 74.53GiB used 74.52GiB path /dev/sda1 devid 3 size 931.51GiB used 606.55GiB path /dev/sdc1 devid 4 size 232.89GiB used 7.52GiB path /dev/sd...Read more