| HDD GURU FORUMS http://forum.hddguru.com/ |
|
| SSD unerase unexpected extremely poor results? http://forum.hddguru.com/viewtopic.php?f=10&t=40329 |
Page 1 of 1 |
| Author: | RPT [ August 25th, 2020, 15:15 ] |
| Post subject: | SSD unerase unexpected extremely poor results? |
Any ideas what's going on? Some silent sector remapping on background? Accidentally deleted folder tree of 2000 documents and photos less than 3% can be successfully recovered. SSD 250 GB and 50 GB free space, after 3 hours of occasional rare usage, after deletion. I'd expect 50%-80% recovery success. Recuva displays "excellent green" for 95% but results still not acceptable. Samsung MZVLB256HAHQ-000L7 Drive is bitlocker encrypted boot C: and unlocked by W10 op system. Recovery software installed from USB stick to physically different SSD drive D: Also recovered files copied to D: Also tried: Efs Recovery Diskinternals uneraser Results are poor and very similar. Most xls, doc, pdf documents not usable. |
|
| Author: | arvika [ August 25th, 2020, 15:18 ] |
| Post subject: | Re: SSD unerase unexpected extremely poor results? |
Read about TRIM. |
|
| Author: | RPT [ August 25th, 2020, 15:28 ] |
| Post subject: | Re: SSD unerase unexpected extremely poor results? |
Does TRIM (remapping I mentioned) means that deleted files from SSD are rarely recoverable? Should I satisfy with this poor recovery results or is there still something what can be done? Indeed: NTFS DisableDeleteNotify = 0" TRIM feature is enabled. Does this SSD TRIM technology turns any "unerase" software now obsolete? |
|
| Author: | Arch Stanton [ August 25th, 2020, 16:11 ] |
| Post subject: | Re: SSD unerase unexpected extremely poor results? |
Quote: Does TRIM (remapping I mentioned) means that deleted files from SSD are rarely recoverable? Yes, data intentionally deleted (delete, format) is pretty much unrecoverable, UNLESS some specific circumstances such as non TRIM 'compatible' file system, interface does not transport all ATA commands for example. Also, there's several things that can happen after TRIM, but most common is Deterministic Read After Trim (DRAT) which will return zeros if you try to read sectors that contained deleted data. In essence TRIM is means o let the drive know I'll no longer be needing the data in LBA n. It's up to the drive's firmware what it does with this information. Logical data recovery tools are still useful to recover data in case data was not intentionally deleted (RAW file system for example). Note that it's not limited to SSD, many SMR drives support TRIM too. |
|
| Author: | abolibibelot [ September 6th, 2020, 19:01 ] |
| Post subject: | Re: SSD unerase unexpected extremely poor results? |
Quote: Recuva displays "excellent green" for 95% but results still not acceptable. Recuva bases its estimation on whether a part or the totality of a file has been overwritten from the filesystem's point of view (if the sectors this file used to occupy are now allocated to another file), it is not aware of the inner workings of the drive, in particular how the trim command can blank data without notifying the filesystem, that's why Recuva reports most deleted files as still being in “excellent” condition. Quote: Does this SSD TRIM technology turns any "unerase" software now obsolete? HDDs are not obsolete, and are probably better for storing personal data in a SNAFU-prone environment. |
|
| Page 1 of 1 | All times are UTC - 5 hours [ DST ] |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|