Is a drive still viable if there is no partition table?

How to use TestDisk to recover lost partition
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theKaz
Posts: 3
Joined: 29 Nov 2013, 22:03

Is a drive still viable if there is no partition table?

#1 Post by theKaz »

I booted up my machine last week and found no data on the SSD (the drive, bought reconditioned, is only a few months old). Booting a copy of Parted Magic (off Hirem's Recovery CD), I tried probing it and came up with nothing.

Since I couldn't find anything mounting the SSD in an external enclosure, I re-imaged it from an old file, back when the disk only had one Windows8 partition -- dd if=/usb_drive/old_disk.img of=/dev/sda

Rebooting now ends up at the blinking-cursor-of-waiting, so back to Parted Magic I go. Running testdisk (6.12), I must select a partition table type of "None"!

The data can be read under Analyse. The geometry is CHS 9730/255/63 with a sector size of 512. Disk SDA is correctly listed as 80 GB/74 GiB.

Running a deeper search, all these errors show up -- bad root cluster, unusual media descriptor, bad number of entries in root dir, incorrect number of heads/cylinder (FAT) !=255, incorrect number of sectors per track (FAT) !=63 -- but on the quick scan, the structure is OK.

Under Advanced:
-the type of the drive is correct (NTFS)

Under boot sector:
-Boot sector status is OK
-can't read backup boot sector (ntfs_boot_sector)
-can't overwrite NTFS backup boot sector
-if I try to rebuild BS, extrapolated BS and current BS mismatch

If I restart testdisk and select the drive's partition type as Intel:
-under Advanced the partition is split between bootable (P) Sys=72 and a hidden (*) Sys=6C.
-under Analyse, (P) Sys=72 is the current partition structure and (*) Sys=6C is under bad relative sector.
--there is a space conflict between the two partitions

I get similar results when I use testdisk 6.14. Why can I see (and recover) the data under a partition table of "None" and, like the topic asks, is this SSD still viable?

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cgrenier
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Re: Is a drive still viable if there is no partition table?

#2 Post by cgrenier »

Well, it's possible to use a non-partioned disk, but not recommended.
old_disk.img is probably an image of a partition, not an image of a disk.
Using GNU parted, you can create a pc/intel partition table, an NTFS partition and using dd, restore to /dev/hda1.

theKaz
Posts: 3
Joined: 29 Nov 2013, 22:03

Re: Is a drive still viable if there is no partition table?

#3 Post by theKaz »

Thank you. That's what I wound up doing, creating a new table and restoring the image to the new partition.

Windows 8 hit a snag, but thanks to a recovery disk, I found I could "create" another copy of Windows upon boot. (I can "hide" it by disabling the boot-loader, but is there a way to remove "Windows 8" and continue to use the "recovered" "Windows 8 (2)"?)

I did a scandisk and chkdsk and found no errors, and SMART data came up with various "old age" labels (but the life-span indicator was still 100%), so I have no idea why the solid state drive did this. I guess I'll have to do regular imaging from now on and have those recovery discs handy. But at least testdisk helped diagnose the drive was "stable" (if not quite "right").

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