Sign in to follow this  
Followers 0
GrofLuigi

Any way to make a Windows 7 partition with larger than 4k clusters?

9 posts in this topic

...That is, the partition where the BCD resides. I have a specific setup which I don't want to disturb:

HnWPIW7.png

This is as seen from Windows 7, which is on the second partition (C:). Dual boot is with XP, which is on the first partition, seen here as F: . When XP is booted, letters are reversed (XP, first partition, is C: and Win7, the second, is F:). It works perfectly for me because every OS is "isolated" in its own partition, sees itself as drive letter C: and the BCD is on the Win7's partition. I use custom boot selector/loader (OSL2000) which is the only thing (tiny) inserted into the first sector (or boot sector, or whatever it's called) of the disk.

Now, this is an SSD and I want to make the cluster size equal to the NAND page size, which is 8k for this Samsung 840 Pro. The purpose is longevity of the SSD. In many places I have read that this is impossible for Windows 7 (BCD). Is that still so? I don't want to create another partition.

I have already enlarged clusters (non-destructively) of the other two partitions from 4k to 8k with Paragon Hard Disk Manager (bootable CD), but when I do it to the Win7 partition, it doesn't boot. Even Paragon says so in the help file. Luckily it was reversable, but of course I still have backups.

So, can I do anything? This is the most written to partition here.

*Edit: and by the way, all partitions are aligned, and I think the alignment won't be disturbed if I don't resize them. Partitions start at offset:

1048576
16013852672
49568284672

GL

Edited by GrofLuigi
0

Share this post


Link to post
Share on other sites

I know very little about this, so I did some search. Does this help any?

I can confirm for you that Windows does not support sector sizes greater than the Memory Manager's page size.

Its from here: http://www.osronline.com/showthread.cfm?link=235324

The only thing on MS about 8k I can find is refering to DOS.

http://support.microsoft.com/kb/67321/en-us

I checked that since in that forum thread there is a link to a 4k OS support article, but makes no mention of 8k.

0

Share this post


Link to post
Share on other sites

@Trip

Yep :) but that is about Physical Sector size (that has nothing actually to do with cluster size).

@Grofluigi

There may be issues with the boot code (and just with it).

Since you do have some 23 Gb free on that device, you can experiment, making a (temporary) partition using that space.

Care to share the source of your opinion of using an 8 Kb cluster being *any* "better"? :unsure:

jaclaz

0

Share this post


Link to post
Share on other sites
@Grofluigi

There may be issues with the boot code (and just with it).

Since you do have some 23 Gb free on that device, you can experiment, making a (temporary) partition using that space.

Care to share the source of your opinion of using an 8 Kb cluster being *any* "better"? :unsure:

jaclaz

That is some magic free space a Magician from Samsung created for me. :w00t: Or, in other (big) words, over-provisioning is supposed to reduce write amplification and ensure write consistency. I don't care much about that second part (write consistency), but since the manufacturer recommends overprovisioning and I can afford to lose some space (I have enough), I go with it.

If I were to make another (boot?) partition, I'd make it at the beginning of the disk, but I don't want to (for now) since everything is so neat and self-contained.

I would like to have 8 Kb clusters because of "write amplification" or, in this case "erase amplification?". Samsung 840 Pro (and every SSD) erases bytes in pages, which in this case is 8 Kb. So in theory, for a file of under 4 Kb in size, it would unnecessarily erase another block of 4 Kb or leave this block "dirty". Or the garbage collection routine would transfer the contents to another block and then erase these two 4 Kb blocks.

GL

0

Share this post


Link to post
Share on other sites

I would like to have 8 Kb clusters because of "write amplification" or, in this case "erase amplification?". Samsung 840 Pro (and every SSD) erases bytes in pages, which in this case is 8 Kb. So in theory, for a file of under 4 Kb in size, it would unnecessarily erase another block of 4 Kb or leave this block "dirty". Or the garbage collection routine would transfer the contents to another block and then erase these two 4 Kb blocks.

I understand that, I was not-so-sure about that particular SSD having 8 Kb pages (and operating on them as "full pages").

In any case - and with all due respect :) - it seems to me like the idea makes little sense. :w00t::ph34r:

Let's take two extremes for the sake of reasoning.

  1. only 1 (one) file below 4 Kb is in the filesystem
  2. several thousands files below 4 Kb are in the filessystem

If #1 the impact of *whatever* is null.

If #2 while the impact of the *whatever* may be relevant or noticeable, in order to reduce it you will further reduce the available capacity of the SSD considerably.

My suggestion was however to try making a new (smallish partition) (Yes, a "boot" partition) not entirely unlike the one Windows 7 makes on a non-partitioned disk, with just the BOOTMGR and the \boot\BCD and see if you can boot from that one the "main" partition with the 8 Kb sized clusters

.

Since it is just a test you can use a part of the space you have free (it is not like having 100 Mb less than the current 23.85 Gb will change *anything*).

jaclaz

0

Share this post


Link to post
Share on other sites

New partition will be my last resort...

I was asking more if there are any new, or old, or unknown to me (ungoogled by me) :) methods to "repair" a BCD on non-4Kb partitions. Maybe third-party tools have progressed (I've heard of EasyBCD, and i think there are others), or something might be possible to be hex-edited, but I need to know what...

And the reason makes perfect sense (at least in my head, obviously :w00t:) when one remembers that SSDs have finite number of writtes.

GL

I would like to have 8 Kb clusters because of "write amplification" or, in this case "erase amplification?". Samsung 840 Pro (and every SSD) erases bytes in pages, which in this case is 8 Kb. So in theory, for a file of under 4 Kb in size, it would unnecessarily erase another block of 4 Kb or leave this block "dirty". Or the garbage collection routine would transfer the contents to another block and then erase these two 4 Kb blocks.

I understand that, I was not-so-sure about that particular SSD having 8 Kb pages (and operating on them as "full pages").

In any case - and with all due respect :) - it seems to me like the idea makes little sense. :w00t::ph34r:

Let's take two extremes for the sake of reasoning.

  1. only 1 (one) file below 4 Kb is in the filesystem
  2. several thousands files below 4 Kb are in the filessystem

If #1 the impact of *whatever* is null.

If #2 while the impact of the *whatever* may be relevant or noticeable, in order to reduce it you will further reduce the available capacity of the SSD considerably.

My suggestion was however to try making a new (smallish partition) (Yes, a "boot" partition) not entirely unlike the one Windows 7 makes on a non-partitioned disk, with just the BOOTMGR and the \boot\BCD and see if you can boot from that one the "main" partition with the 8 Kb sized clusters

.

Since it is just a test you can use a part of the space you have free (it is not like having 100 Mb less than the current 23.85 Gb will change *anything*).

jaclaz

0

Share this post


Link to post
Share on other sites

I cannot believe that - IF the issue is in the booting only - it can be solved by modifying the \boot\BCD (which AFAIK contains NOT any particular info related to the filesystem and it's cluster size).

If you don't want to add a partition, not even temprorarily for the sake of the test) , you can do with a boot floppy image:

http://www.multibooters.co.uk/floppy.html

an image like described can be mapped and chainloaded by grub4dos alright, and it will need not any re-partitioning, while removing the doubt that it is a BOOTMGR issue of some kind, which is a mere (though educated ;)) guess :ph34r: based on your "it doesn't boot." report (which is not an actual description of what actually happens :whistle:).

About the "sense", what I was trying to highlight is that the theoretical "increased wear" may happen only on a limited number of cells, since the number of files less than 4 Kb that are often re-written on a "normal" Windows 7 system are very few, maybe the relevance of the issue is "amplified" by any file which is a multiple of 4 Kb but not of 8 Kb? :unsure:

And, call me reckless if you want :w00t:, according to these:

http://www.anandtech.com/show/7173/samsung-ssd-840-evo-review-120gb-250gb-500gb-750gb-1tb-models-tested

http://www.anandtech.com/show/6328/samsung-ssd-840-pro-256gb-review

http://www.anandtech.com/show/6459/samsung-ssd-840-testing-the-endurance-of-tlc-nand

one of those thingies are guaranteed for 5 years and are estimated at around 11 years of duration.

By that time we will likely be using Windows 13.4 SP2¼ and 256 Gb ;) will be the space needed for just the bootmanager and configuration file.

jaclaz

P.S.: After all my guess was educated enough:

http://www.terabyteunlimited.com/kb/article.php?id=392

http://support.microsoft.com/kb/2272294

Edited by jaclaz
0

Share this post


Link to post
Share on other sites

"it doesn't boot." report - I forgot the exact words, they were on a black screen, not terribly scary, but not big friendly letters either. ;)

Due to lack of free time, I will suspend my efforts for now and come back to it later.

Thank you Jaclaz

0

Share this post


Link to post
Share on other sites

Well, seemingly not much efforts needed, at the light of the Terabyte page, only to try the Windows 8 version of the BOOTMGR.

Hard to believe :w00t:, but after all Windows 8 does have *some* uses. ;)

jaclaz

0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0

  • Recently Browsing   0 members

    No registered users viewing this page.