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Best Practice for System Drive Size vs Storage Drive Size RRS feed

  • Question

  •  

    I just ordered a EX470 with an additional 750gb drive.  Is there any reason why I would want/need to swap the system drive so that it is located on the 750gb vs the 500gb drive?  I remember someone telling me that the system drive should always be the largest drive but I'm not certain of that now.

     

    If so, is it as simple as installing the drive and running a system restore/installation from the included disks?

     

    Thanks in advance!

    D3

    Tuesday, June 17, 2008 6:29 PM

Answers

  • Microsoft's recommendation is that the system drive be the largest drive, at the time you build your system. This is because the size of the system drive sets a limit on some of Windows Home Server's capabilities (e.g. the largest single file or file set that you can copy to your server in a single pass), and you are future-proofing by using your largest drive.

    That said, I don't feel there's any pressing need for a system drive in excess of 200-300 GB. While it's true that the system drive limits you, I don't think it's likely that you will encounter those limits any time soon with a drive of that size. Or you could simply buy a drive in the "sweet spot" right now, which is around 500-750 GB.
    Wednesday, June 18, 2008 1:07 AM
    Moderator

All replies

  • Microsoft's recommendation is that the system drive be the largest drive, at the time you build your system. This is because the size of the system drive sets a limit on some of Windows Home Server's capabilities (e.g. the largest single file or file set that you can copy to your server in a single pass), and you are future-proofing by using your largest drive.

    That said, I don't feel there's any pressing need for a system drive in excess of 200-300 GB. While it's true that the system drive limits you, I don't think it's likely that you will encounter those limits any time soon with a drive of that size. Or you could simply buy a drive in the "sweet spot" right now, which is around 500-750 GB.
    Wednesday, June 18, 2008 1:07 AM
    Moderator
  •  

    Not sure if that is exactly the case. Remember that the System drive is split into partitions, one 20GB for the 'system', and the rest for data.  I just ran into a problem doing some testing on power pack 1, so i'm not sure if its related.  Have a 80 GB ide drive (removable for testing purposes) as the primary drive.  Secondary drive is a 1TB Sata drive.  Since the initial data drive is on the IDE drive, its about 60GB.  It seems that there needs to be enough room for duplication on the initial drive.  I ran out of disc space because of duplication being turned on.  Even though there was 800GB free (with both drives combined).  Still very concerning though, in that I turned off duplication for the share that I was copying data to.  I show 25GB free on the IDE drive, while the system now shows a total of 830GB free.  As I copy data share, the IDE drive slowly gets smaller.  I'm wondering when/if it will again run out of space even though there is a fairly large total amount space free. 

     

    Is this by design ?

     

    -Steve

    Wednesday, June 18, 2008 3:07 AM
  • Steve, if you have only two drives, then yes your system drive is used for duplication. In that scenario, when your system drive begins to run low on space, you will see a network health warning. You will add another drive (or two) to the server, and over time as you continue to use your server it will migrate data off of your system drive to a secondary drive.

    Other things that your system drive are potentially used for in a two-drive server include storage for components of the backup database, and tombstones. The backup database will normally be stored on one drive in your storage pool, but if it grows too large for a single drive, or if that drive fills with files in your shares, components may be forced back to the system drive. And tombstones are always stored on the system drive. From your description, I would think you're seeing the creation of tombstones.
    Wednesday, June 18, 2008 12:04 PM
    Moderator
  • Thanks for that useful information!

     

    I just want to clarify somthing...please correct me if I'm wrong.

     

    What I'm hearing is that if I have a 2-drive system with the system drive at 500gb and the storage drive at 750gb and duplication is turned on, I will be limited to no more than 500gb of space.  The primary purpose of the WHS will be for backup and data storage so duplication will always be turned on.

     

    In addition, I will be retiring a server that has 200gb and 500gb SATA drives.  If I were to reuse both of those drives, that gives me a 4-drive system.  In that scenario (with duplication on), which of the 4 drives would be the best to use as the system drive?  (200, 500, or 750)

     

    Thanks again for your help!

    D3

    Wednesday, June 18, 2008 12:17 PM
  • D3,

    If your going to re-build the server with your 'new' various drives, it will depend on just how many very large files you would intend transferring to the server. However, I would go for the 200 as the system drive, then add the two 500 drives. This would mean that no duplicated data would be stored on the system disk at all, and would be identical storage space. Then, you have the option of adding the 750 to the pool, or using that drive as a 'backup' disk for your shared folders.

    In general, it appears the most efficient option is to add drives in pairs - apart from the system disk - so, you would go,3 to 5 to 7 etc.

     

    Colin

     

    Wednesday, June 18, 2008 2:54 PM
  • So, then... If you are not planning on using duplication (maybe offsite backup, like mozy), is there a way to just span the drives to get the most usage of space ?  From what it looks like, either way, the largest drive should be installed first, just in case you want duplication without going to 3 drives.  I guess in the old 'business' practice, you always wanted the smallest drive for boot.  Then all the data would reside on the next set(s) of drives.  This way, if you ever had to re-install the OS, it wouldnt effect any of the data drives.  I know drives are relatively cheap now, so maybe its not that big an issue.

    Wednesday, June 18, 2008 4:39 PM
  • WHS doesn't work like that! To fully understand, you really need to read through the Documentation, particularly the Drive Extender paper. In essence, WHS uses the first boot drive as both system and data drive; the first 20GB is taken as drive C:, while the balance, irrespective of disk size, becomes drive D:. All other drives that you add, then in effect, become an extension of that storage space.

     

    Colin 

    Wednesday, June 18, 2008 5:21 PM
  • Actually, I left out one important detail!

     

    The 200gb drive that I mentioned earlier is a slower 1.5gb SATA drive.  Once I retire my existing server, I will end up with 2-750gb (SATA II) drives and the 500gb that the EX470 comes with...whatever that is.  I have another 500gb drive available but I'm reserving that drive specifically for my MCE box and it doesn't need to be backed up or duplicated.

     

    After reading through this forum etc, I'm thinking the optimal setup is to leave the 200gb drive out completely, leave the system partition on the 500gb as installed at the factory, and just add the two 750gb drives for storage with duplication.

     

    I'm thinking that having the 500gb as the primary data partition should be large enough before it moves the data over to the secondary data partition on the other two drives.

     

    D3

     

    Wednesday, June 18, 2008 5:39 PM
  • But that is where the problem is... Its not that straight forward.  Because if duplication is turned on, and you have only 2 drives, you can conceivably run out of space on the first drive if it is smaller than the 2nd.  Like the other poster mentioned, You need to at least have 3 drives so that the 1st drive (data partition) wont fill up.  Also, I wouldnt say 'D:' because the actual size of D: (under my computer) will only show the physical space available on that drive.  You would have to look at either the Server Console (For total space available), or Disk Manager (to see by 'Drive').

    Wednesday, June 18, 2008 5:40 PM
  • I have multiple drive system and am with Ken and Colin on this.  I started with couple of 500 GB drives and still have 500 GB as primary drive.  Over time, since the first public beta days in Feb or March 2007, as drives filled up and although I still had 445 GB free in primary partition, I continued to add new drives to avoid storing data in primary partition.  It has now 10 drives, 6 TB total, and currently have 745 GB free.  Sounds good, but in reality, taking away 445 GB for primary partition and 200 GB, approximately 20 GB allowed free space in each of the 10 drives, my true free space is just little over 100 GB.  Very soon, I'm faced with adding another drive, even though I still have that 445 GB free in primary partition. Any large harddrive you use as primary drive will be grossly underused as you don't really want to use it to store data.  It will affect overall system performance, especially if you are using to stream movies, home movies or otherwise.  I've already decided a month or so ago to switch the system drive to 200 GB drive I have lying around to utilize that underused drive/space, just that I've been procrastinating since doing a clean install, my preferred install method, is pain.  Most of you will eventually run into similar situations and will likely end up having that same disgusted look as I have.  That is, having to add another brand new drive when you still have that large space available on your primary partition.

     

    Folks, if you are just starting to build your system or still have a fairly new system with little data, just blindly trust Ken and Colin's word for it on this one and start with the drive capacity they recommend.  You'll be glad you did down the road.

     

    Wednesday, June 18, 2008 6:22 PM
  • I'm assuming that I don't want to use the 200gb drive as my system drive because it's a SATA vs SATA II and, therefore, would slow down everything. 

     

    Is that logic flawed?

     

    D3

     

    Wednesday, June 18, 2008 6:26 PM
  • In practice, there is very little that will max out SATA I or II transfer speeds. WHS isn't meant for high-performance read/write file operations. I expect there will be little difference in using a drive that is 200 GB, 500 GB, or 750 GB.

    You can only transfer 180 GB (200 - 20 GB) to the landing zone at once, however I doubt you'd be doing such imports at once much.
    Wednesday, June 18, 2008 7:15 PM
  • Don't get me wrong.  I also agree with Ken & Colin.  Was just saying, realistically that you really want to have more that 2 drives.  A 2 Drive system with a 200GB 'System' drive, could conceivably fill up before the 2nd drive gets full, depending on the size of the 2nd drive.

     

    Wednesday, June 18, 2008 7:25 PM
  • That's good news.  Now I'm back to a 4-disk system setup as follows:

     

    200gb SATA I - System drive

    500gb SATA II - Storage drive I

    750gb SATA II - Storage drive II

    750gb SATA II - System backup drive

     

    Make sense?

    D3

    Wednesday, June 18, 2008 7:41 PM
  • ok.. now i'm not sure that this is the place for this, but does a SATA II Controller operate at the lowest transfer rate of the lowest speed drive, or will it adjust to each drive accordingly.  In other words, because there is a SATA I drive on the controller, will it run that transfer rate on the SATA II Drives ?

     

    syssjr

    Wednesday, June 18, 2008 7:46 PM
  • Ken Warren said:

    Microsoft's recommendation is that the system drive be the largest drive, at the time you build your system. This is because the size of the system drive sets a limit on some of Windows Home Server's capabilities (e.g. the largest single file or file set that you can copy to your server in a single pass), and you are future-proofing by using your largest drive.

    That said, I don't feel there's any pressing need for a system drive in excess of 200-300 GB. While it's true that the system drive limits you, I don't think it's likely that you will encounter those limits any time soon with a drive of that size. Or you could simply buy a drive in the "sweet spot" right now, which is around 500-750 GB.

    The getting started guide specifies a 70gb drive as a min requirement and a 300gb drive as the recommended size. Word of mouth since the beta has always been " the primary drive should be the largest drive in your system.  With the advent of 1tb and now 1.5tb drives - the word of mouth recommendation seems to be stretching the point beyond that of reasonableness.

    Having spent the last two days researching this issue - this is the most complete, understandable explanation I've found to date.  Having said that, several additional questions:

    I'm building a new box that will initially have (4) 1tb pool drives and a system drive.  More pool drives will be added in the future as required - hopefully keeping the LZ free of data.


    1) Up until now, I've been planning on using a 1tb drive as a system drive - but the more I've read about the changes implemented with  PP1, it makes sense to have enough pool storage available from the beginning to keep the system drive free of data and only contain tombstones.  That being the case - can I be sure that no data is ever stored on the landing zone long term, providing enough pool storage is available on other drives? Even with file duplication on - they will be duplicated to 2 of the 4 pool drives - as opposed to the LZ.


    2) The only benefit to having a larger landing zone is to permit vista and server 2008 a large enough open target to begin a transfer.  If you transfer in smaller units - then there is no need to push the limits of the LZ capacity limits. User choice. However, the more tombstones - the smaller the usable calculated LZ for file transfer authorization. (Not a concern with XP).


    3) What happens if the LZ is too small over time to hold all the tombstones from a multi-drive system (lots and lots of little files)?  Do you get an error message and need to replace the primary drive or are they stored elsewhere in the pool?

    4) I understand that the current file handing process introduced in PP1 may be revised in a future update. Keeping that in mind - am I still good to go with a mid-size drive - or should I plan for the future and install a 1tb drive as my primary drive?


    5) I have 2 available mid-size drives on hand to choose from 320gb and 500gb.  Recognizing that everyones system configuration needs are different - which make the best compromise - using the 500gb drive for my system drive (or is that still overkill - and I should go with the 320gb?)  
     

    I'm sure I'm overthinking this - but there's too much conflicting information floating around on this issue for my comfort level....

    Tuesday, November 25, 2008 1:24 AM
  • I don't believe that WHS uses the landing zone effect anymore.

    While copying files to my server I checked the Disk Managment add-in and noticed that the data was going straight to storage drive #3 and passing the lanading zone.
    Tuesday, November 25, 2008 1:32 AM