# Mounting a software RAID partition to recover



## perlcat (Jan 31, 2012)

I *had* a working NAS configured with one 1,5 TB drive. However, it does not recognize the /usr partition according to the RAID error code. It does recognize and boot off the drive, so I think that an OS reload would ultimately get me my free space -- but as I would be BOFH'ing myself, I'd rather not try that until all is clearly lost. The RAID manufacturer does not provide utilities for debugging/dumping data, so any tools/solutions I come up with would be external.  

I was able to connect the drive via a USB adapter to my FreeBSD laptop for analysis. I think I still have data on it, but I cannot seem to mount the 3rd partition, which would be /usr:


```
poot# mount -t ext2fs /dev/da1s3 /mnt
mount: /dev/da1s3 : Invalid argument
```

This is my system -- 8.2-STABLE, rebuilt my kernel last week to get VirtualBox updated:


```
poot# uname -a
FreeBSD poot.rtfmcomputing.com 8.2-STABLE FreeBSD 8.2-STABLE #4: Sun Jan 22 10:12:14 CST 2012     root@poot.rtfmcomputing.com:/usr/obj/usr/src/sys/GENERIC  amd64
```

This is the same error I get for the first partition (/), and as it boots off that, I know that it may not be a bad partition, but most likely is something I am doing or not doing:


```
poot# mount -t ext2fs /dev/da1s1 /mnt/usb
mount: /dev/da1s1 : Invalid argument
```
and it looks like a regular linux RAID. 


```
poot# fdisk /dev/da1
******* Working on device /dev/da1 *******
parameters extracted from in-core disklabel are:
cylinders=182401 heads=255 sectors/track=63 (16065 blks/cyl)

Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=182401 heads=255 sectors/track=63 (16065 blks/cyl)

Media sector size is 512
Warning: BIOS sector numbering starts with sector 1
Information from DOS bootblock is:
The data for partition 1 is:
sysid 253 (0xfd),(unknown)
    start 63, size 3919797 (1913 Meg), flag 0
        beg: cyl 0/ head 1/ sector 1;
        end: cyl 243/ head 254/ sector 63
The data for partition 2 is:
sysid 253 (0xfd),(unknown)
    start 3919860, size 514080 (251 Meg), flag 0
        beg: cyl 244/ head 0/ sector 1;
        end: cyl 275/ head 254/ sector 63
The data for partition 3 is:
sysid 253 (0xfd),(unknown)
    start 4433940, size 2925838125 (1428631 Meg), flag 0
        beg: cyl 276/ head 0/ sector 1;
        end: cyl 1023/ head 254/ sector 63
The data for partition 4 is:
<UNUSED>
```

and the partition 0xFD is a Linux software RAID, which makes sense.

If I run tune2fs against that device, I get:

```
tune2fs 1.41.14 (22-Dec-2010)
Filesystem volume name:   <none>
Last mounted on:          <not available>
Filesystem UUID:          d55f70b0-7787-4323-b4ef-27ecb281d5b9
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal resize_inode dir_index filetype needs_recovery sparse_super large_file
Filesystem flags:         unsigned_directory_hash 
Default mount options:    (none)
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              182878208
Block count:              365729765
Reserved block count:     0
Free blocks:              3965090
Free inodes:              180201500
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      936
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         16384
Inode blocks per group:   512
Filesystem created:       Wed Feb 10 04:37:18 2010
Last mount time:          Thu Sep 22 17:22:03 2011
Last write time:          Thu Sep 22 17:22:03 2011
Mount count:              38
Maximum mount count:      31
Last checked:             Wed Feb 10 04:37:18 2010
Check interval:           15552000 (6 months)
Next check after:         Mon Aug  9 05:37:18 2010
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group wheel)
First inode:              11
Inode size:               128
Journal inode:            8
Default directory hash:   tea
Directory Hash Seed:      43c1c77a-757f-4335-89ed-591bf0f6f351
Journal backup:           inode blocks
```

Any idea why, with the Inode size being 128, I can't mount this? Is there any way that I can recover the files on the 3rd partition? If I can just get to them by inode, I can write a script or something to recover what I need and move on.

I do have ex2fs loaded:


```
poot# kldstat 
Id Refs Address            Size     Name
 1   20 0xffffffff80100000 de1c60   kernel
 2    1 0xffffffff80ee2000 25268    snd_hda.ko
 3    2 0xffffffff80f08000 75890    sound.ko
 4    1 0xffffffff80f7e000 4c070    vboxdrv.ko
 5    1 0xffffffff80fcb000 52d8     atapicam.ko
 6    1 0xffffffff81012000 1dea8    linux.ko
 7    1 0xffffffff81030000 b760     ext2fs.ko
```

and the dmesg where the drive is added:


```
ugen1.2: <JMicron> at usbus1
umass1: <MSC Bulk-Only Transfer> on usbus1
umass1:  SCSI over Bulk-Only; quirks = 0x4000
umass1:3:1:-1: Attached to scbus3
da1 at umass-sim1 bus 1 scbus3 target 0 lun 0
da1: <ST315003 41AS > Fixed Direct Access SCSI-2 device 
da1: 40.000MB/s transfers
WARNING: mount of da1s3 denied due to unsupported optional features
```

I'm guessing the warning that appears in /var/log/messages has a lot to do with my problem.


```
Jan 31 00:08:28 poot kernel: WARNING: mount of da1s3 denied due to unsupported optional features
```

Any suggestions as to what I should do?


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## l2f (Dec 9, 2016)

Dear,

Try to mount read only: -o ro (just a guess)


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## SirDice (Dec 12, 2016)

l2f, you're replying to a 4 year old thread.


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