Identifying Mount and Cache Options in Windows Client cvgathers

 

In Windows snapshots from clients the parameters for the various mount and cache settings, “Advanced Mount Options” and "Advanced Cache Options" in the GUI, are in the cvgather.cvntcfgimpexp.txt file.

 

GUI options :

 

 

 

 

The following tables shows the description, parameter and default settings along with examples of non-default settings. If the parameter isn't in the file then it's set to the default

 

Most of the parameters are simply the hexadecimal value given but the Mountoptions and Mountoptions2 paramters are words with key bits set in them so different combinations of settings will yield different numbers.

 

EG, in the SNFS/cvgather.cvntcfgimpexp.txt file from the cvgather :

 

    "BufferCacheCap"=dword:00000100          The “Minimum Total Cache Size” is set to 256M (Hexadecimal 100 = Decimal 256)

    "BufCacheIods"=dword:00000010            The “Number of Threads” is set to 16

    "BufCacheReadAhead"=dword:00000040       The “Number of Read-ahead Buffers” is set to 64

  

Advanced Mount Options

 

    GUI description                Registry setting    Default     Example parameters and equivalents

 

Mount Control :

    Mount Retransmit Limit         MountRetrans              1     00000002 =     2   00000004 =     4

    Hard Mount                     MountOption         <unset>     80000080 = unset   80000084 =   set

    Allow Diskless Mount           MountOption         <unset>     80000080 = unset   80002080 =   set

    Read Only                      MountOption         <unset>     80000080 = unset   80000081 =   set

    Restrict Pre-allocation API    MountOption         <unset>     80000080 = unset   84000080 =   set

Threads:

    Number of Async I/O Threads    AioThreads                8     00000010 =    16   00000014 =    20

    Number of System Threads       Threads                  12     00000018 =    24   0000001e =    30

Timeouts:

    Message Timeout x 1/10th Sec   Timeout                  50     00000064 =   100   00000078 =   120

    Message Retry Count            ReTrans                  12     00000018 =    24   0000001e =    30

    Retry I/O’s Forever                                  <set>     (Toggles with below, MountOptions2)

    Allow I/O Timeouts             MountOptions2       <unset>     00000000 = unset   00000020 =   set

    I/O Retry Time Seconds         IORetryTime               0     00000001 =     1   0000000a =    10

    I/O Penalty Time Seconds       IOPenaltyTime           300     00000190 =   400   00000258 =   600

                                   + MountOptions2                 00000000 = unset   00000010 =   set

    Fast Failover Detection        MountOptions        <unset>     80000080 = unset   80004080 =   set

    Hard Reconnect                 MountOptions        <unset>     80000080 = unset   80000082 =   set

 

Quality of Service (QOS)

    Token Hold Seconds             NrtioTokenHold           60     00000064 =   100   00000078 =   120

 

Advanced Cache Options

 

Data Buffer Cache :

    Individual Buffer Size         CacheBufSize             64K    00020000 =   128K  00030000 =   192K

    Minimum Total Cache Size       BufferCacheCap          256M    00000100 =   256M  00000400 =     1G

    Auto-DMA Read                  BufCacheAutoDmaRdLen      1M    00400001 =     4M  01000001=     16M

    Auto-DMA Write                 BufCacheAutoDmaWrtLen     1M    00400001 =     4M  01000001=     16M     

    Number of Read-ahead Buffers   BufCacheReadAhead        16     00000020 =    32   00000040 =    64

    Number of Threads              BufCacheIods              8     00000010 =    16   00000020 =    32

 

Attribute Flush Time:

    Seconds for Non-Shared         AttrFlushSecs            30     0000002d =    45   0000003c =    60

    Seconds for Shared             ShAttrFlushSecs           2     00000005 =     5   0000000a =    10

    Delay Atime Updates            MountOptions        <unset>     80000080 = unset   80040080 =   set

 

Metadata/Inode Cache:

    Low Water Mark                 CacheLowWaterMark         1K    00000800 =     2K  00001000 =     4K

    High Water Mark                CacheHighWaterMark        3K    00001800 =     6K  00002000 =     8K

    Max Entries                    CacheMax                  4K    00002000 =     8K  00004000 =    16K

    Purge Period (seconds)         CacheHoldSecs            45     0000003c =    60   0000005a =    90

 

Directory Cache :

    Minimum Directory Cache Size   DirCacheSize             10M    01400000 =    20M  02000000 =    32M