1lsm_volume_cache_info(3)  Libstoragemgmt C API Manual lsm_volume_cache_info(3)
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NAME

6       lsm_volume_cache_info  -  Query RAM cache information for the specified
7       volume.
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SYNOPSIS

10       int  lsm_volume_cache_info  (lsm_connect  *conn,  lsm_volume   *volume,
11       uint32_t  *write_cache_policy,  uint32_t  *write_cache_status, uint32_t
12       *read_cache_policy,  uint32_t  *read_cache_status,   uint32_t   *physi‐
13       cal_disk_cache, lsm_flag flags);
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ARGUMENTS

16       conn        Valid connection.
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18       volume      Pointer of lsm_volume.
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20       write_cache_policy
21                   uint32_t.  The  write  cache  policy.  Valid  values are: *
22                   LSM_VOLUME_WRITE_CACHE_POLICY_WRITE_BACK
23                      The storage system will use write  back  mode  if  cache
24                   hardware
25                      found.  * LSM_VOLUME_WRITE_CACHE_POLICY_AUTO
26                      The  controller  will  use  write  back  mode  when bat‐
27                   tery/capacitor
28                      is in good health, otherwise,  write  through  mode.   *
29                   LSM_VOLUME_WRITE_CACHE_POLICY_WRITE_THROUGH
30                      The  storage  system  will  use  write  through mode.  *
31                   LSM_VOLUME_WRITE_CACHE_POLICY_UNKNOWN
32                      Plugin failed to detect this setting.
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34       write_cache_status
35                   uint32_t.  The status of write cache. Valid values  are:  *
36                   LSM_VOLUME_WRITE_CACHE_STATUS_WRITE_THROUGH    *   LSM_VOL‐
37                   UME_WRITE_CACHE_STATUS_WRITE_BACK        *         LSM_VOL‐
38                   UME_WRITE_CACHE_STATUS_UNKNOWN
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40       read_cache_policy
41                   uint32_t.  The  policy  for read cache. Valid values are: *
42                   LSM_VOLUME_READ_CACHE_POLICY_ENABLED
43                      Read cache is enabled,  when  reading  I/O  on  previous
44                   unchanged
45                      written I/O or read I/O in cache will be returned to I/O
46                      initiator    immediately    without   checking   backing
47                   store(normally
48                      disk).  * LSM_VOLUME_READ_CACHE_POLICY_DISABLED
49                      Read cache is  disabled.   *  LSM_VOLUME_READ_CACHE_POL‐
50                   ICY_UNKNOWN
51                      Plugin failed to detect the read cache policy.
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53       read_cache_status
54                   uint32_t.  The  status  of  read cache. Valid values are: *
55                   LSM_VOLUME_READ_CACHE_STATUS_ENABLED       *       LSM_VOL‐
56                   UME_READ_CACHE_STATUS_DISABLED * LSM_VOLUME_READ_CACHE_STA‐
57                   TUS_UNKNOWN
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59       physical_disk_cache
60                   Whether physical disk's cache is enabled or not. Please  be
61                   advised,  HDD's  physical  disk ram cache might not be pro‐
62                   tected by storage system's battery or capacitor  on  sudden
63                   power  loss,  you could lose data if a power failure occurs
64                   during a write process.  For  SSD's  physical  disk  cache,
65                   please check with the vendor of your hardware RAID card and
66                   SSD  disk.    Valid   values   are:   *   LSM_VOLUME_PHYSI‐
67                   CAL_DISK_CACHE_ENABLED
68                       Physical   disk  cache  enabled.   *  LSM_VOLUME_PHYSI‐
69                   CAL_DISK_CACHE_DISABLED
70                       Physical  disk  cache  disabled.   *  LSM_VOLUME_PHYSI‐
71                   CAL_DISK_CACHE_USE_DISK_SETTING
72                       Physical  disk  cache  is determined by the disk vendor
73                   via
74                       physical disks' SCSI caching mode page(0x08  page).  It
75                   is
76                       strongly suggested to change this value to
77                       LSM_VOLUME_PHYSICAL_DISK_CACHE_ENABLED or
78                       LSM_VOLUME_PHYSICAL_DISK_CACHE_DISABLED    *   LSM_VOL‐
79                   UME_PHYSICAL_DISK_CACHE_UNKNOWN
80                       Plugin failed to detect the physical disk status.
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82       flags       Reserved for future use, must be LSM_CLIENT_FLAG_RSVD.
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VERSION

85       1.3.
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DESCRIPTION

88       Query RAM cache settings for the specified volume.
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CAPABILITY

91       LSM_CAP_VOLUME_CACHE_INFO
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RETURN

94       Error code as enumerated by 'lsm_error_number'.
95           * LSM_ERR_OK
96               On success.
97           * LSM_ERR_NOT_FOUND_VOLUME
98               When volume not found.
99           * LSM_ERR_INVALID_ARGUMENT
100               When any argument is NULL or invalid flags.
101           * LSM_ERR_NO_SUPPORT
102               Not supported.
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106April 2019                   lsm_volume_cache_info    lsm_volume_cache_info(3)
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