Partition Recovery

DrVirus · Post by **DrVirus** » 26 Aug 2009, 23:35

Guys i have another problem. I have an external HDD of 160GB. It has a lot of my datas. All of my movies and most of my mp3. It was doing fine all this time but suddenly I can't access it anymore my vista is telling me to format it in order to access

I need the data back. So some kind of recovery is called for. I'm thinking http://www.partitionrecovery.net/ or stellar phonix what do you guys suggest ??

Post by **Gogeta70** » 27 Aug 2009, 04:28

Brings back memories...

http://suck-o.com/modules.php?name=Foru ... pic&t=4567 ^_^

Anyway, if i remember correctly, testdisk did the trick for me. You can get it here: http://www.cgsecurity.org/wiki/TestDisk

moudy · Post by **moudy** » 27 Aug 2009, 05:39

since this issue was brought up; about HDD's... How much reliable are these devices, and what are the pros ans cons compared to a flash device ?
Definitely storage capacity is way up more in HDD's than flash devices...
can any one stress more on the topic, and thanks

Post by **DNR** » 27 Aug 2009, 13:20

You are referring to SSD vs HDD. Solid State Hardrives are completely different in mechanics, while the file system is the same. SSD are also not all constructed the same, cheaper ones could very well have the FAT on the same chip as the data..if one gets corrupted, both become useless. With a HDD you had the option of swapping out parts like the r/w head, or the firmware board to repair a crashed HDD. You can even remove the platters and place into a similar HDD, but SSD will not have those options to recover data. SSD harddrives are considered slower than the fastest HDD, hence they are used in netbooks and not considered powerful.

DNR

Post by **bad_brain** » 27 Aug 2009, 14:19

low level recovery (reading the raw data) should be no problem on SSD drives, but the opposite can be a problem: deleting data from the drive so it can't be recovered, I remember that I have read an article about Flash cards and that it is almost impossible to wipe such cards in a secure way, and the same problem might appear on SSD drives too...

the good point in SSD drives is that there are no mechanical parts, no head crash anymore. but yeah, cheap ones are pretty slow...even a regular SATA drive is often faster, and the really fast SSD ones still cost as much as a halfway decent new computer.

about reliability:
depends of course on the usage, the position (yeah, I am still convinced that it plays a role, we had a thread about that a while ago), and the cooling of the HDD. but in general techs say after 2 years the danger of a data loss increases exponential (on "regular" HDDs). that's why I would never buy a cheap noname HDD, the best ones are imo WD and Seagate, hands off from Excelstor....had 2 HDDs and both died within a few weeks.

leetnigga · Post by **leetnigga** » 27 Aug 2009, 15:06

DNR wrote:SSD harddrives are considered slower than the fastest HDD

Wikipedia:

Extremely low read latency times, as SSD seek-times are orders of magnitude lower than the best hard disk drives, as of 2008.

Seek times are orders of magnitude lower than those of the best HDDs, making SSDs faster than HDDs. I thought this was pretty obvious

Post by **bad_brain** » 27 Aug 2009, 15:44

true, but "being a HDD" is more than just reading. when you compare the write speed regular HDDs are still faster (and not just a little), in copying (read/write at the same time) both technologies are almost equal.

Post by **DNR** » 27 Aug 2009, 16:50

Don't get all your facts from wikipedia

There is more to the story than Speed, and debates about benchmarking, there is even a theory of use for SSDs - that SSDs should complement HDDs and not REPLACE them. There is a debate about the fastest HDD can still be faster than an SSD when you consider all the overhead a SSD has. What HDD did they compare, what SSD did they compare against? Who knows, but the debate can be found every where.

The seek speed might not include the slowdown caused by the SSDs emulation of a HDD as it performs other duties like reading and writing.

What IS Obvious, is comparing HDDs and SSDs IS like comparing apples and oranges - when you consider the technologies used to manage a SSD, like wear-leveling, Flash based media, flash type memory, NAND flash memory, read/write algoritum, etc - even one SSD system can have different technology than the other SSD.

I use SS memory sticks only as a file repository, not as a virtual disk. Some professionals agree that the SSD should not run programs on it, but should be used as a data repository. This goes with the theory that SSDs should be used appropriately in a combination of HDD(more capacity, longer life when used as a virtual disk) and even tape drives(for backup, long term data storage).

Here are some clips from other sources..

Phil Mills, chairman of the Solid State Storage Initiative, said the performance numbers most manufacturers use now for marketing represent a drive's "burst rate" -- not its steady state or average read rate. "So there's already a huge difference between out-of-the-box versus constant use," he said. "And then, in both burst mode and steady state, there are huge differences in performance between manufacturers."

Users typically notice that an SSD drive runs at the manufacturer's stated peak I/O performance at first, but soon after that it begins to drop. That's because, unlike a hard disk drive, any write operation to an SSD requires not one step, but two: an erase followed by the write.

When an SSD is new, the NAND flash memory inside it has been pre-erased; Users start with a clean slate, so to speak. But, as data is written to the drive, data management algorithms in the controller begin to move that data around the flash memory in an operation known as wear-leveling. Even though wear-leveling is meant to prolong the life of the drive, it can eventually lead to performance issues.

SSD performance and endurance are related. Generally, the poorer the performance of a drive, the shorter the lifespan. That's because the management overhead of an SSD is related to how many writes and erases to the drive take place. The more write/erase cycles there are, the shorter the drive's lifespan.

For example, a read-modify-write algorithm in an SSD controller will take a block about to be written to, retrieve any data already in it, mark the block for deletion, redistribute the old data, then lay down the new data in the old block.

"So you had to write that old data back again," said Grimsrud, whose group developed some of the core technology for Intel's SSDs. "None of that is progress in terms of what the user was trying to do with the new data. It was all just overhead. That's the crux of the problem with NAND [memory] management -- all the granularity involved in managing it.

---

"Computerworld compared four disks, two popular solid state drives and two Seagate mechanical drives, for read/write performance, bootup speed, CPU utilization and other metrics. The question asked by the reviewer is whether it's worth spending an additional $550 for a SSD in your PC/laptop or to plunk down the extra $1,300 for an SSD-equipped MacBook Air? The answer is a resounding No. From the story: "Neither of the SSDs fared very well when having data copied to them. Crucial (SSD) needed 243 seconds and Ridata (SSD) took 264.5 seconds. The Momentus and Barracuda hard drives shaved nearly a full minute from those times at 185 seconds. In the other direction, copying the data from the drives, Crucial sprinted ahead at 130.7 seconds, but the mechanical Momentus drive wasn't far behind at 144.7 seconds."

I would chose a more reliable, cheaper device considering the speed difference. The rules change when you compare laptop SSD with Desktop SSD as well.

I believe the above HDDs run at 7k rpms, of course there are HDDs that run 5.4k to 10k rpms. It can even depend on the OS you chose to use the SSD on.
You have to look at the overall picture, the seek, the read and write times, the costs, reliability and purpose you intend for the storage device.

"An empty [SSD] drive will perform better than one written to. We all know that," said Alvin Cox, co-chairman of the Joint Electronic Device Engineering Council's (JEDEC) JC-64.8 subcommittee for SSDs, .. Cox, a senior staff engineer at Seagate, said a quality SSD should last between five and 10 years.

----
http://www.computerworld.com/s/article/ ... me=Storage

http://www.ehow.com/how_2259376_usb-fla ... onger.html

DNR

leetnigga · Post by **leetnigga** » 27 Aug 2009, 23:31

Okay, those are all great points.

But don't go saying

DNR wrote:Don't get all your facts from wikipedia

When it was indeed true and you support it in the rest of your post.

Post by **DNR** » 28 Aug 2009, 13:03

Ok, I meant the wiki statement is not to be accepted as entirely true. That is why I cautioned about not relying on one source for your knowledge. I also tried to stay away from manufacturer's sites as their claims always come out higher than review/test articles.

OCZ announced, at least to our knowledge, the fastest SATA II SSD to date, as far as the spec sheet is concerned. Available in 60 GB and 120 GB versions, the new Vertex EX 2.5” drives promise a sequential data read speed of “up to” 260 MB/s, and write speeds of “up to” 200 and 210 MB/s, respectively. Sustained read speeds are rated at “up to” 100 MB/s.
...
If you know that SATA II allows a bandwidth of about 300 MB/s, why would you spend your hard-earned money on those (current) expensive drives that top out at read speeds of 200 MB/s or less?

While we already know that SATA III will become available in some high-end storage device with a bandwidth of 600 MB/s later this year, SATA II is destined to soon become a much more interesting option, especially since we are seeing vendors approaching that 300 MB/s mark.

http://www.tgdaily.com/content/view/42083/135/

There are give and take with each action on a SSD - seek, read, and write. A SSD might have a faster seek time, but it can lose due to read and write times being factored into real world use of a SSD.
Its not just the test method can be biased or faulty, but inherent problems related to SSD technology. Manufacturers admit the SSDs are fast at the beginning, but level out to a slower rate as it is used. This may not directly mean a pre-flushed, empty SSD is slanting the test results but also different propriety algoritums or programming tricks put into different makers SSDs.

The fact is HDDS with the appropriate technology is faster than almost all SSD available to you.

Check out the latest issue of Maximum PC, they put out a Sept 09 issue about building the best PC. Even their top of the line PC used a combo of SSD and HDD. The other ranking PCs had HDDs like:

Western Digital 500gb HDD
3gbps data rate
32mb buffer, 7,200rpm
with Dual Processors (yes, on the HDD!)
$69USD
http://www.newegg.com/Product/Product.a ... 6822136320
"Raptor
Avg. Transfer Rate: 72.1 MB/Sec
Access Time: 8.1 ms
Burst Rate: 115.3 MB/Sec
Operating Temp: 107 degrees F

Caviar Black
Avg. Transfer Rate: 72.7 MB/Sec
Access Time: 12.5 ms
Burst Rate: 146.8 MB/Sec
Operating Temp: 87 degrees F "

Western Digital VelociRaptor WD3000HLFS 300GB 10000 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive - OEM
Cache: 16MB
Average Seek Time: 4.2ms
Average Write Time: 4.7ms
Packaging: Bare Drive
Average Latency: 3ms (nominal)

You also consider HDD technology of eSATA (eSATA devices will typically run at 1.5Gbps) and SATA-II ( data speeds of 3Gbps. Not all SATA-II* devices are required to run at 3Gbps, but the increased speed is there for applications and drives that want to take advantage of it. 3Gbps drives are completely backward compatible—you can plug them into a first-generation SATA system, but they'll just move data at a maximum 1.5Gbps)

*
What was previously dubbed "SATA-II" has been redefined to include a variety of technologies. most people only think of SATA-II as offering a 3Gbps (gigabits per second) serial pipe for data.

http://www.extremetech.com/article2/0,2 ... 252,00.asp

---

Seagate told TG Daily that hard drives that transfer data at more than 200 MB/s should be common in 2010, and achieve a performance only the fastest SSDs can deliver today.

http://www.tgdaily.com/content/view/41664/135/

Again, maybe comparing apples and oranges, very expensive oranges. I also noticed that Sata-II tech can be applied to SSD as well, but the expense of $200+ difference maybe be anyone's roadblock.

DNR

leetnigga · Post by **leetnigga** » 28 Aug 2009, 13:15

DNR wrote:Ok, I meant the wiki statement is not to be accepted as entirely true.

It is. Seek time != read speed.

http://en.wikipedia.org/wiki/Seek_time

Have a nice day.

Post by **DNR** » 28 Aug 2009, 14:21

The point is SSD is NOT always faster than a HDD.

You can play games with wording, but I think people want to know the full deal.

Do you have any nice days?

DNR

leetnigga · Post by **leetnigga** » 28 Aug 2009, 14:32

DNR wrote:The point is SSD is NOT always faster than a HDD.

You can play games with wording, but I think people want to know the full deal.

Of course, I'm just saying your Wikipedia hatin' was uncalled for

DNR wrote:Do you have any nice days?

Every single one of 'em

DrVirus · Post by **DrVirus** » 29 Aug 2009, 02:06

And they say I'm wrong when I say "one suck-o member" is looking for fights in the forum and will become the infamous post stopper soon enough !

Post by **lilrofl** » 29 Aug 2009, 15:09

you know i wonder sometimes how to wipe completely an SSD, but I have been using one fore a little over a year now and I have to say I like it for what I use it for.

I use a 40GB SLC SSD for my operating system on my notebook. I use a journaling file system to mitigate the read/write limits assumed, but an SLC drive (albeit small) has a limit much higher then the MLC drives that are out there.

I am writing this a little hasty so I haven't mucked it up with stats and numbers... but I can if there is an interest.

Truth is they both have strengths and weaknesses and neither an HDD or and SSD is perfect for every occasion... although I think that a good HDD is a better fit for a generic choice then a single SSD would be... except in the case of a small netbook where the SSD uses vastly less power, and with no moving parts produces less heat, which may or may not matter when the mud slinging starts =)