I have been using a Seagate NAS SRN01C with 4TB of space.  I am somewhat familiar with linux systems.  I mainly access this drive through ssh on my local network, and occasionally scp from the NAS to other remote spaces.Hardware Specs from MFG:Hardware Specifications Drive capacity: 2TB, 3TB, 4TB, or 5TB USB drive format: NTFS, HFS, or HFS+ Network connectivity: One 10/100/1000 Ethernet port USB connectivity: One USB 2.0 port for connecting external storage devices to theSeagate Central Seagate Central deviceLast night I unplugged my NAS --both the power and cat5--and today I cannot find any of my data.  My three user folders exist when attempting to connect through windows finder.  However, when I ssh into the NAS, none of my data is where it always used to be: /Data/[name_of_user_folder]/...Contents of my /Data/ directory, which used to have the following three folders in there: Stephan, Silas, Publicroot@(none):/Data# lsPublic  TwonkyData  dbd(no idea what TwonkyData is -- first time I'm seeing it)Contents of root: /root@(none):/# ls -lhtotal 104Kdrwxr-xr-x   6 root root 4.0K Jul  4 12:21 Datadrwxrwxr-x   2 root root 4.0K Jun 14 22:57 Trumpdrwxr-xr-x   3 root root 4.0K Jul  4 12:02 Updatedrwxrwxr-x   3 root root 4.0K Jul 26  2013 appsdrwxrwxr-x   2 root root 4.0K Oct  6  2015 bindrwxrwxr-x   5 root root 4.0K Sep 16  2015 blackarmordrwxr-xr-x   2 root root 4.0K Sep 16  2015 bootdrwxrwxr-x   6 root root 4.0K Jul 26  2013 cirrus-rw-rw-rw-   1 root root 1.3K Sep 16  2015 cornerstonedrwxr-xr-x  13 root root 3.6K Jul  4 12:31 devdrwxr-xr-x   4 root root 4.0K Oct  5  2015 downloadsdrwxrwxr-x  48 root root 4.0K Jul  4 12:31 etcdrwxrwxr-x   4 root root 4.0K Jul 26  2013 homedrwxrwxr-x   5 root root 4.0K Oct  5  2015 liblrwxrwxrwx   1 root root   12 Oct  6  2015 linuxrc -> /bin/busyboxdrwxrwxr-x  10 root root 4.0K Sep 16  2015 mediadrwxrwxr-x   8 root root 4.0K Jul  4 12:19 media_serverdrwxrwxr-x   6 root root 4.0K Sep 16  2015 mindsourcedrwxrwxr-x  20 root root 4.0K Sep 16  2015 mntdrwx------   2 root root 4.0K Oct  5  2015 nfsdr-xr-xr-x 109 root root    0 Dec 31  1969 procdrwxr-xr-x   3 root root 4.0K Oct  6  2015 satellite_appdrwxrwxr-x   2 root root 4.0K Oct  6  2015 sbindrwxrwxrwx   7 root root 4.0K Jun 14 22:48 sharesdrwxr-xr-x   3 root root 4.0K Oct  6  2015 staticdrwxr-xr-x  12 root root    0 Jul  4 08:21 syslrwxrwxrwx   1 root root    8 Jul  4 08:21 tmp -> /var/tmpdrwxrwxr-x  13 root root 4.0K Dec 31  1969 usrdrwxrwxr-x  12 root root 4.0K Oct  6  2015 vardrwxrwxr-x   5 root root 4.0K Sep 16  2015 wwwdrwxrwxr-x   2 root root 4.0K Sep 16  2015 www_servicesDoing a df -h, I see that 100% of the drive space has been utilized --- but I know for sure I have at least 2TB free, so something is up.Here is the output of df -hFilesystem            Size  Used Avail Use% Mounted onrootfs               1008M 1008M     0 100% //dev/root            1008M 1008M     0 100% /devtmpfs              125M  1.6M  123M   2% /dev/dev/sda5            1008M  159M  799M  17% /usr/confignone                  125M  1.6M  123M   2% /devtmpfs                 125M  5.5M  119M   5% /var/volatiletmpfs                 125M     0  125M   0% /dev/shmtmpfs                 125M     0  125M   0% /media/ram/dev/sda5            1008M 1008M     0 100% /My question: does anyone have a certain set of procedures I could use to check the disk? Or, does anyone recognize these symptoms and know a cure?ADD'L OUTPUTS:blkidroot@(none):/# blkid/dev/sda1: UUID=adcb7b24-cf53-4ec9-8fa1-5bc1af93f73d TYPE=ext2/dev/sda2: UUID=ea7b5585-726e-4cfd-b04b-e31789634314 TYPE=ext2/dev/sda3: UUID=c8f7706e-8ae9-4896-95b7-90a8f03043eb TYPE=ext4/dev/sda4: UUID=77885248-849b-4e6f-bd67-965510456c9e TYPE=ext4/dev/sda5: LABEL=Config UUID=1c1afe7b-344c-4c24-bf54-550fcad7aef1    TYPE=ext4/dev/sda6: LABEL=Swap UUID=a4b7e139-c0c2-4387-bebe-a1a1d156a175 TYPE=swap /dev/sda7: LABEL=Update UUID=c14fd994-d990-426c-a828-179aaf3cec08 TYPE=ext4/dev/sda8: UUID=wY9v4o-iaHL-bxOi-Z2NL-zYZe-hepM-T27T3l TYPE=LVM2_member/dev/mapper/vg1-lv1: LABEL=Data UUID=73186851-6a51-4545-a87c-1df92dd0c544 TYPE=ext4-/proc/mdstat gives me a no such file or directoryvgdisplayroot@(none):/# vgdisplay  --- Volume group ---  VG Name               vg1  System ID  Format                lvm2  Metadata Areas        1  Metadata Sequence No  2  VG Access             read/write  VG Status             resizable  MAX LV                0  Cur LV                1  Open LV               0  Max PV                0  Cur PV                1  Act PV                1  VG Size               3.63 TiB  PE Size               4.00 MiB  Total PE              952571  Alloc PE / Size       952571 / 3.63 TiB  Free  PE / Size       0 / 0  VG UUID               lgCPRE-gWkT-RQ2A-LrbJ-30oW-K9Dx-7DRNy7  /etc/lvm/cache/.cache.tmp: write error failed: No space left on deviceuname -aroot@(none):/# uname -aLinux (none) 2.6.35.13-cavm1.whitney-econa.whitney-econa #1 Wed Sep 16  15:47:59 PDT 2015 armv6l GNU/Linux
No DATA on SEAGATE NAS SRN01C
data;nas