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#324610 - 25/07/2009 21:00 Re: SSDs [Re: mlord]
pim
addict

Registered: 14/11/2000
Posts: 474
Loc: The Hague, the Netherlands
Originally Posted By: mlord

1) upgrade to OCZ firmware 1.3 immediately, if not already on the unit.

2) ensure the drive is set for highest performance:
hdparm -W1 -A1 /dev/sdX


All of that was set on the drive out of the box.

Originally Posted By: mlord

3) stop benchmarking, and just enjoy the speed! wink


Yes, I will, but before these drives end up in their destined computers, I'd like to see where else they might make a difference, and where not.

Originally Posted By: mlord

benchmarks generally show that the OCZ Vertex doesn't really take much advantage of it.


A performance drop of up to 60% isn't really an advantage indeed. smile

Thanks,
Pim

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#324616 - 26/07/2009 00:52 Re: SSDs [Re: pim]
mlord
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Registered: 29/08/2000
Posts: 14491
Loc: Canada
OTOH.. the Data Set Management "Trim" command may be coming soon to the Indilinx drives, including the OCZ Vertex. There was a post to that effect on the OCZ BBS.

Not that I might know anything further about such..

wink

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#324621 - 26/07/2009 08:02 Re: SSDs [Re: mlord]
BartDG
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Registered: 20/05/2001
Posts: 2616
Loc: Bruges, Belgium
Ah, that trimming command, is that to automatically 'zero' all the unused bits, so the SSD only had to do one action to change a bit? (and thus makes it faster?) I've read something about that, and for now you still need to run a dedicated command for that. So this will be implemented in the drive's firmware? Sweet!
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#324624 - 26/07/2009 11:52 Re: SSDs [Re: BartDG]
mlord
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Registered: 29/08/2000
Posts: 14491
Loc: Canada
TRIM is simply a way for the operating system to tell the drive firmware about discarded sectors on the media.

So when one deletes a file, the O/S could issue some TRIM commands to inform the SSD firmware that the data in those sectors is no longer relevant.

The firmware can then use this knowledge to make more intelligent decisions about wear-leveling, garbage collection, and so forth.

Otherwise, without TRIM, the SSD firmware *must* assume that any sector that has *ever* been written to by sofware, still holds valid data. Forever. And cannot be erased/cycled without first copying the data elsewhere.

So TRIM is potentially a huge win for drive wear-leveling and overall performance.

Cheers

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#324629 - 26/07/2009 14:08 Re: SSDs [Re: mlord]
BartDG
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Registered: 20/05/2001
Posts: 2616
Loc: Bruges, Belgium
Aha! I can see how this can indeed make a substantial difference! Thanks for the explanation Mark!
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#324644 - 26/07/2009 20:22 Re: SSDs -- unintended consequences [Re: BartDG]
gbeer
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Registered: 17/12/2000
Posts: 2665
Loc: Manteca, California
So if drives begin truly cleaning themselves, when files are deleted, file recovery or drive forensics will be more difficult/impossible.

I'm sure there will be those who will think this is a bad thing.
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#324646 - 26/07/2009 20:32 Re: SSDs -- unintended consequences [Re: gbeer]
andym
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Registered: 17/01/2002
Posts: 3996
Loc: Manchester UK
Originally Posted By: gbeer
I'm sure there will be those who will think this is a bad thing.


Indeed, one of them reads this forum.
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Cheers,

Andy M

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#324669 - 27/07/2009 14:30 Re: SSDs -- unintended consequences [Re: gbeer]
BartDG
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Registered: 20/05/2001
Posts: 2616
Loc: Bruges, Belgium
Originally Posted By: gbeer
So if drives begin truly cleaning themselves, when files are deleted, file recovery or drive forensics will be more difficult/impossible.

I can see how this might be considered a bad thing. Maybe it will be a user selectable setting.
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#324671 - 27/07/2009 17:23 Re: SSDs -- unintended consequences [Re: gbeer]
peter
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Registered: 13/07/2000
Posts: 4180
Loc: Cambridge, England
Originally Posted By: gbeer
So if drives begin truly cleaning themselves, when files are deleted, file recovery or drive forensics will be more difficult/impossible.

I'd imagine they won't actually clean themselves on delete, they'll just put those pages back in the pool available for subsequent writes. So it's more like increasing the (already existing) chance that a subsequent write will overwrite the thing you hoped to recover.

Peter

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#324691 - 27/07/2009 21:56 Re: SSDs -- unintended consequences [Re: peter]
tman
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Registered: 24/12/2001
Posts: 5528
Originally Posted By: peter
I'd imagine they won't actually clean themselves on delete, they'll just put those pages back in the pool available for subsequent writes.

The drive controller can erase old pages that have been trimmed when it doesn't have anything else to do. Depending on what the drive controller firmware does, those erased pages could be gone pretty quickly.

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#324695 - 28/07/2009 00:20 Re: SSDs -- unintended consequences [Re: peter]
mlord
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Registered: 29/08/2000
Posts: 14491
Loc: Canada
Originally Posted By: peter
'd imagine they won't actually clean themselves on delete, they'll just put those pages back in the pool available for subsequent writes.

It's not the firmware, really, but a combination of the O/S sending a DSM/TRIM command, and the firmware then doing what it likes with it.

On the pre-production unit I have here some drives, it does might erase the data after a TRIM command, eventually.. but not always immediately. wink

Cheers


Edited by mlord (28/07/2009 00:23)

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#324854 - 03/08/2009 14:35 Re: SSDs -- unintended consequences [Re: mlord]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Today I finally got the opportunity to run my wiper.sh (version 1.6) TRIM utility for real on my live 120GB SSD. This is the first time in months that the firmware has known about all of the free blocks on the drive, and it does seem to have speeded things up a bit. I don't run detailed benchmarks, though.

Cheers

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#325019 - 10/08/2009 20:39 Re: SSDs -- unintended consequences [Re: mlord]
drakino
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Registered: 08/06/1999
Posts: 7868
Looking at the benchmarks from the link below, even 5 minutes of idle time is enough to get most of the performance back.

http://hothardware.com/News/OCZ-and-Indilinx-Collaborate-On-New-SSD-Garbage-Collection-Scheme/

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#325021 - 11/08/2009 04:27 Re: SSDs -- unintended consequences [Re: drakino]
tman
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Registered: 24/12/2001
Posts: 5528
Originally Posted By: drakino
Looking at the benchmarks from the link below, even 5 minutes of idle time is enough to get most of the performance back.

http://hothardware.com/News/OCZ-and-Indilinx-Collaborate-On-New-SSD-Garbage-Collection-Scheme/

How does it know what blocks are actually free?

The Samsung flash controllers apparently know enough about NTFS to read the block bitmap to erase the unused blocks. This obviously isn't great if you don't use NTFS...

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#325040 - 11/08/2009 20:22 Re: SSDs -- unintended consequences [Re: tman]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Heh.. and obviously not a great idea for when NTFS adds new features someday..

For general purpose GC, the OCZ firmware does NOT know anything about which blocks are free. Rather, it simply does what the Intel SSDs do: shuffles blocks around to create erase-sized blocks of free space.

All of these drives permanently reserve a few percent of raw capacity for GC/spares, so there is always some free space.

With TRIM, the drives then *do* know about real free space, and in theory can do an even better job of things.

Cheers

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#325041 - 11/08/2009 20:23 Re: SSDs -- unintended consequences [Re: mlord]
mlord
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Registered: 29/08/2000
Posts: 14491
Loc: Canada
Note that "industrial grade" SSDs, or "server rated" SSDs, may reserve as much as 50% or more of raw flash capacity for GC and wear leveling.

Cheers

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#326173 - 18/09/2009 10:28 Re: SSDs -- unintended consequences [Re: mlord]
pim
addict

Registered: 14/11/2000
Posts: 474
Loc: The Hague, the Netherlands
Originally Posted By: mlord
Today I finally got the opportunity to run my wiper.sh (version 1.6) TRIM utility for real on my live 120GB SSD.
Cheers


Can I use hdparm/wiper.sh to erase a drive completely?
I'd like to do this before restoring a windows image using partimage.

Thanks,
Pim

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#326175 - 18/09/2009 11:20 Re: SSDs -- unintended consequences [Re: pim]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Originally Posted By: pim
Can I use hdparm/wiper.sh to erase a drive completely?

Like this:
Code:
hdparm --security-set-pass NULL /dev/sdX
hdparm --security-erase    NULL /dev/sdX


Cheers

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#326177 - 18/09/2009 11:40 Re: SSDs -- unintended consequences [Re: mlord]
pim
addict

Registered: 14/11/2000
Posts: 474
Loc: The Hague, the Netherlands
I'm not sure you understood I want to erase the SSD for performance reasons, not security reasons.

I would expect something like

Code:
hdparm --trim-sector-ranges ALL /dev/sdX


The SSD is an Intel X25-M 160GB.

Thanks,
Pim

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#326178 - 18/09/2009 11:57 Re: SSDs -- unintended consequences [Re: pim]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Originally Posted By: pim
I'm not sure you understood I want to erase the SSD for performance reasons, not security reasons.

No, I understood perfectly what you wanted. smile

The recipe I gave above does exactly what you want, on *any* SSD.

Cheers

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#326180 - 18/09/2009 12:24 Re: SSDs -- erasing them completely [Re: mlord]
pim
addict

Registered: 14/11/2000
Posts: 474
Loc: The Hague, the Netherlands
Very good.

Can I use hdparm 9.12 from Fedora 11 or do I need to compile a more recent version?

Thanks,
Pim

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#326184 - 18/09/2009 13:11 Re: SSDs -- erasing them completely [Re: pim]
pim
addict

Registered: 14/11/2000
Posts: 474
Loc: The Hague, the Netherlands
Hmmm...
Code:
# cat /proc/version 
Linux version 2.6.29.5-191.fc11.x86_64
 ([email protected])
 (gcc version 4.4.0 20090506 (Red Hat 4.4.0-4) (GCC) )
 #1 SMP Tue Jun 16 23:23:21 EDT 2009
# ./hdparm -V
hdparm v9.27
# lsscsi
[0:0:0:0]    cd/dvd  SONY     DVD-ROM DDU1615  FYS3  /dev/sr0 
[2:0:0:0]    disk    ATA      INTEL SSDSA2MH16 045C  /dev/sda 
[3:0:0:0]    disk    ATA      WDC WD1600BEKT-0 11.0  /dev/sdb 
[4:0:0:0]    disk    ATA      Maxtor 6Y120L0   YAR4  /dev/sdc 
# ./hdparm --security-set-pass NULL /dev/sda
security_password=""

/dev/sda:
 Issuing SECURITY_SET_PASS command, password="", user=master, mode=high
SECURITY_SET_PASS: Input/output error
# ./hdparm --security-erase NULL /dev/sda
security_password=""

/dev/sda:
 Issuing SECURITY_ERASE command, password="", user=master
ERASE_PREPARE: Input/output error


Pim


Edited by pim (18/09/2009 14:38)
Edit Reason: folded a gawdawful long line

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#326186 - 18/09/2009 13:24 Re: SSDs -- erasing them completely [Re: pim]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Either the BIOS or the operating system has "frozen" security
on the drive. Just power the drive off/on (within 5 seconds),
wait another half minute, then do the commands again.

-ml

And trim that gawdawful long line from your posting,
so that we don't all have to scroll sideways for the rest
of this thread!!


Edited by mlord (18/09/2009 13:26)

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#326195 - 18/09/2009 15:11 Re: SSDs -- erasing them completely [Re: mlord]
pim
addict

Registered: 14/11/2000
Posts: 474
Loc: The Hague, the Netherlands
Originally Posted By: mlord
Either the BIOS or the operating system has "frozen" security
on the drive. Just power the drive off/on (within 5 seconds),
wait another half minute, then do the commands again.


Moved the drive from my "clone" PC to the target laptop.
Still the same errors.

Maybe this is relevant:

Code:
hdparm -I /dev/sdb

[ .... ]

Security: 
	Master password revision code = 65534
		supported
	not	enabled
	not	locked
		frozen
	not	expired: security count
		supported: enhanced erase
	2min for SECURITY ERASE UNIT. 2min for ENHANCED SECURITY ERASE UNIT.


Pim

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#326208 - 18/09/2009 19:18 Re: SSDs -- erasing them completely [Re: pim]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Originally Posted By: pim
Maybe this is relevant:
..
frozen

Exactly as I said: the drive has been frozen by the BIOS or operating system.

The only way to un-freeze a drive is a power cycle. So just hot unplug it from the laptop, and plug it directly back in again within a few seconds. Linux won't care, and the drive will then be unfrozen.

Cheers

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#327119 - 27/10/2009 21:00 Re: SSDs -- erasing them completely [Re: mlord]
hybrid8
carpal tunnel

Registered: 12/11/2001
Posts: 7738
Loc: Toronto, CANADA
Any thoughts on this entry level product: Kingston SSDNow V Series 40GB Boot Drive

I'd like to use something similar as a boot drive for my PVR server which runs 24/7.
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Twisted Melon : Fine Mac OS Software

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#327125 - 27/10/2009 22:27 Re: SSDs -- erasing them completely [Re: hybrid8]
gbeer
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Registered: 17/12/2000
Posts: 2665
Loc: Manteca, California
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#327126 - 27/10/2009 23:53 Re: SSDs -- erasing them completely [Re: gbeer]
drakino
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Registered: 08/06/1999
Posts: 7868
That Kingston looks nice since it's an Intel drive.

I'm holding off for now, hoping for a slightly more affordable high speed SSD in the 256gb range. Probably going to be hard to hold out though, as we have an Intel SSD on order at work for eval.

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#327135 - 28/10/2009 11:08 Re: SSDs -- erasing them completely [Re: hybrid8]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Originally Posted By: hybrid8
Any thoughts on this entry level product: Kingston SSDNow V Series 40GB Boot Drive

It may be "Intel built", but from the specs it is pretty obviously not an Intel SSD. Much slower than the real Intel models.

Until we see some independent reviews of it, I'd stay away from this or any SSD. The crappy ones can be really, really bad.

EDIT: Mmm.. anandtech reviews are often reliable, and they seem to like it, so.. go crazy if the speed is good enough for the price

Go with a real Intel SSD, or with an OCZ Agility (or Vertex). Those are all very, very fast, and well supported with firmware updates (including TRIM).

My PVR here now boots/runs from a barebones 32GB SSD I got as a "factory sample". Just a bare PCB with chips, no case. smile


Edited by mlord (28/10/2009 11:14)

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#327137 - 28/10/2009 11:12 Re: SSDs -- erasing them completely [Re: mlord]
hybrid8
carpal tunnel

Registered: 12/11/2001
Posts: 7738
Loc: Toronto, CANADA
The Anandtech review is pretty decent. It's mainly a review about the Intel SSDs but they've recently expanded it to include the Kingston. Newegg is supposed to debut the product at US$85 after a rebate on November 9th (down from about $115)
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