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How many SATA controllers can a system handle? RRS feed

  • Question

  • I have a GiGa Byte MB (EP43T-UD3L) which comes with 6 Sata II ports of which I have 5 HDD & 1 Blue ray Cd connected. All HDD are MBR, single partition, Simple drive volumes.

    And feeling the need for more storage space, I installed a High Point Rocket RAID 622, 2 port (ext) controller with 2 (4 drive ext, RAID 0) units (8 drive total) port A & B. At 6Tb ea unit I used GPT partitions and sliced them into 2 TB simple drives, then mounted them into 6 NTFS folders on the C:\ drive (as I hate all the drive letters as it is).

    My OS is WHS-2011 x64 and I've been reading horror stories about it and GPT partitions on the boot drive, and it not being able to back up anything larger than 2Tbs, is any of that true? I haven't had any problems yet as my largest drive is 1.5 Tbs, and my client backups are under 2 Tbs also, but that will change as technology marches forwards.

    Now I am trying to add a Syba 2 port Sata3 controller, and the system just doesn't see it. I've tried it in several PCIe x1 slots and no go.

    I then tried a IDE to Sata converter on the IDE channel, and it still didn't work, all the lights are ON the board, so I assume it has power.

    I then pulled the drive out and tried it in a docking station USB3, and it worked fine, I then deleted its partition.

    I have a 700W duel rail PWS and I am using ADCI, and all the other drive are working fine. It's a mystery to me, any ideas?

    I guess I could try a different sata cable, but that doesn't explain why device manager doesn't see it.

    Thanks for any insight.

    Wednesday, March 27, 2013 3:29 AM

Answers

  • Regarding SATA controllers, it's possible you have a hardware incompatibility, or a driver issue of some sort. We aren't going to be able to do much to help you sort that out, as we don't have your hardware sitting in front of us.

    Regarding RAID: Don't use RAID 0. RAID 0 (striping) is statistically less reliable than the least reliable drive in the array, so you can expect that the MTBF will be lower than that of any individual drive in the array. In addition, when you lose a drive in a RAID 0 array, you lose everything on the array. As a result, you should use RAID 0 only in applications where driver performance matters above all else, and all data to be placed on the array can easily be recreated. Other RAID levels should be thought of as useful for "high availability" applications; RAID is not designed to be a technology for protecting your data. For purposes of Windows Home Server, configure your external HBA to expose the bare drives to the OS, and use those drives individually. And come up with a backup strategy that covers all your important data, and which stores backups off-site.

    Regarding GPT, drive size limits, etc.: Some true, some not. Windows Home Server's built in server backup won't back up more than 2 TB at once, and won't back up to or from a logical disk larger than 2 TB in size. Windows Home Server 2011 will, if you allow it, split a larger disk up into one or more 2 TB partitions, and one partition of less than 2 TB. Since the largest logical disk a server will typically have is 2 TB, this limits the size of a single share to 2 TB (since a single share can't be split between multiple file systems in Windows). This includes the client backup database, thus limiting the client backups (and the largest single client backup) to 2 TB.


    I'm not on the WHS team, I just post a lot. :)

    • Marked as answer by Andy Qi Thursday, April 4, 2013 9:07 AM
    Wednesday, March 27, 2013 3:48 AM

All replies

  • Regarding SATA controllers, it's possible you have a hardware incompatibility, or a driver issue of some sort. We aren't going to be able to do much to help you sort that out, as we don't have your hardware sitting in front of us.

    Regarding RAID: Don't use RAID 0. RAID 0 (striping) is statistically less reliable than the least reliable drive in the array, so you can expect that the MTBF will be lower than that of any individual drive in the array. In addition, when you lose a drive in a RAID 0 array, you lose everything on the array. As a result, you should use RAID 0 only in applications where driver performance matters above all else, and all data to be placed on the array can easily be recreated. Other RAID levels should be thought of as useful for "high availability" applications; RAID is not designed to be a technology for protecting your data. For purposes of Windows Home Server, configure your external HBA to expose the bare drives to the OS, and use those drives individually. And come up with a backup strategy that covers all your important data, and which stores backups off-site.

    Regarding GPT, drive size limits, etc.: Some true, some not. Windows Home Server's built in server backup won't back up more than 2 TB at once, and won't back up to or from a logical disk larger than 2 TB in size. Windows Home Server 2011 will, if you allow it, split a larger disk up into one or more 2 TB partitions, and one partition of less than 2 TB. Since the largest logical disk a server will typically have is 2 TB, this limits the size of a single share to 2 TB (since a single share can't be split between multiple file systems in Windows). This includes the client backup database, thus limiting the client backups (and the largest single client backup) to 2 TB.


    I'm not on the WHS team, I just post a lot. :)

    • Marked as answer by Andy Qi Thursday, April 4, 2013 9:07 AM
    Wednesday, March 27, 2013 3:48 AM
  • Hi Ken, thanks for your reply. I understand what you're saying about RAID-0 and I can easly convert to JBOB for each drive.

    I don't understand what you said about my hardware; do you mean my MB working with the 2 controllers or the 2 controllers working with each other? After all I am the great experimenter, I was told by San Digital tech that 2 Rocket RAID controllers would not work in the same system, and this must be true with other controllers as well.

    OK, I'm still confused about WHS server backup because I started with my external unit A, I first made it GPT, and then split it into three 2 Tb simple discs. But when I configured server backup, it deleted the three and made one big 6 Tb disc, all by itself. And I would assume that it would have copied data until it was full. But you're saying it would stop at 2Tb regardless of total size, right? It would seem that server backup needs tweaking.

    I am able to redirect the client folder to it's own drive 1.5 Tb, if I add clients would I also be able to redirect each to it's own drive?

    I'm already doing Bare Metal Backups now for my server and one client, and I want to add another client. WHS was the first backup software I ever used that worked perfect, my client was restored as if the disaster never happened. I tried several Imaging, cloning software to restore it, and each time I had to reactivate Windows making it a different machine than before.

    So How do you get WHS to split up the drive on it's own? When I did my client restore it didn't do anything for me, it did allow me to use drive manager to set up all the partitions, but I had to manually match up each partition for the restore. And of course after everything was done restoring, I could resize the partitions as I wanted too.

    Wednesday, March 27, 2013 8:31 PM
  • This includes the client backup database, thus limiting the client backups (and the largest single client backup) to 2 TB.


    FWIW, it is perfectly possible to use a higher capacity volume on the server to host the client backups (mine is currently on a 4Tb spanned volume), provided you don't need to include the client backups in server backup. This is necessary if you have greater than a combined 2Tb of client data to be backed up, as unfortunately WHS 2011 provides no means of splitting the client backups across multiple 2Tb volumes.

    As Ken mentions, using spanning or striping to create a larger contiguous volume from smaller disks is riskier than using bare drives, so do this only for data you can easily recreate (like client backups).


    • Edited by Gary Voth Wednesday, April 10, 2013 3:11 PM
    Wednesday, April 10, 2013 3:08 PM