Root dbspace的primary chunk的前12页是系统保留页。从第2页开始，页成对分组以相互支持；它们会交替更新，以防止不完整的更新破坏关键恢复数据。Root Reserved Pages是数据库的核心组成部分，它包含了数据库系统的元数据和关键信息。以下是有关这些保留页的一些信息：
Page zero
第0页包含了SinoDB版权和版本信息，最小页面大小以及系统创建的日期和时间。这是一个重要的信息页，通常包含数据库引擎的版本和创建日期。
Configuration page
第1页包含了服务器上次联机时存储在系统配置文件中的信息的副本。这些信息来自数据库配置文件（通常是$INFORMIXDIR/etc/$ONCONFIG），它们对于数据库的运行非常关键。
Checkpoint/logical log pages
第2页和第3页是检查点/逻辑日志页。当前检查点/逻辑日志页面提供最后一个检查点的位置、日期和时间，以及每个逻辑日志的位置和当前状态。
Dbspace pages
第4页和第5页是关于dbspace（数据库空间）的页面。当前dbspace页面上的每个条目都跟踪dbspace的状态、位置、数据和创建时间。
Primary chunk pages
第6页和第7页是关于主数据块的页面。它们包含了有关服务器上每个主块的信息，包括区块路径名、大小、偏移量和状态等信息。
Mirror chunk pages
第8页和第9页是镜像块页。这些页的结构与主块页相同。
Archive pages
第10页和第11页（0xa和0xb）是归档页。这些页面包含有关在服务器上执行的最新存档的信息。
使用oncheck -pr命令可以查看这些保留页的信息。这对于数据库管理员和运维人员来说是非常有用的，因为它们包含了关键的数据库配置和状态信息，可以帮助监视数据库的健康和性能。
以下是oncheck -pr一个用于查看这些保留页信息的例子：
[sinodbms@node31 ~]$ oncheck -pr
Validating Sinoregal SinoDB Dynamic Server reserved pages
Validating PAGE_PZERO...
Identity Sinoregal SinoDB Dynamic
Server Copyright 2001,
2023 Sinoregal Corporat
Database system state 0
Database system flags 0x9
64-bit server
BigChunk page flags are not in use
Page Size 2048 (b)
Date/Time created 09/17/2023 22:59:21
Version number of creator 29
UID of rootdbs creator 1001
Index Page Logging OFF
HA Disk Owner <null>
Validating PAGE_CONFIG...
ROOTNAME rootdbs
ROOTPATH /home/sinodbms/chunks/rootdbs
ROOTOFFSET 0 (k)
ROOTSIZE 300000 (k)
MIRROR 0
MIRRORPATH /home/sinodbms/tmp/demo_on.root_mirror
MIRROROFFSET 0 (k)
DBSERVERNAME sinodb0918
SERVERNUM 18
MSGPATH /home/sinodbms/tmp/online.log
TAPEDEV /dev/null
TAPESIZE 0 (k)
TAPEBLK 32 (k)
LTAPEDEV /dev/null
LTAPESIZE 0 (k)
LTAPEBLK 32 (k)
PHYSFILE 50000 (k)
PHYSBUFF 128 (k)
LOGFILES 6
LOGSIZE 10000 (k)
LOGBUFF 64 (k)
DYNAMIC_LOGS 2
LTXHWM 70 (%)
LTXEHWM 80 (%)
RESIDENT 0
CLEANERS 8
SHMBASE 0x44000000
CKPTINTVL 300 (s)
DBSPACETEMP
PLOG_OVERFLOW_PATH /home/sinodbms/tmp
BTSCANNER num=1,threshold=5000,rangesize=-1,alice=6,compression=med
RTO_SERVER_RESTART 0 (s)
RAS_PLOG_SPEED 25000
RAS_LLOG_SPEED 0
AUTO_TUNE_SERVER_SIZE OFF
AUTO_LLOG 0
AUTO_LRU_TUNING 1
AUTO_CKPTS 1
AUTO_AIOVPS 1
BACKUP_FILTER
RESTORE_FILTER
STORAGE_FULL_ALARM 600,3
CONVERSION_GUARD 2
RESTORE_POINT_DIR /home/sinodbms/tmp
SP_AUTOEXPAND 1
SP_THRESHOLD 0
FULL_DISK_INIT 0
AUTO_READAHEAD 1,128
UNSECURE_ONSTAT 0
DISK_ENCRYPTION
SHMVIRTSIZE 32656 (k)
STACKSIZE 64 (k)
SHMADD 8192
SHMTOTAL 0 (k)
ALARMPROGRAM /home/sinodbms/etc/alarmprogram.sh
VP_MEMORY_CACHE_KB 0
LOW_MEMORY_RESERVE 0
LOW_MEMORY_MGR 0
SBSPACENAME
SYSSBSPACENAME
SBSPACETEMP
DS_MAX_QUERIES 2
DS_TOTAL_MEMORY 512
DS_MAX_SCANS 1048576
OPTCOMPIND 2
MAX_PDQPRIORITY 100
DIRECTIVES 1
OPT_GOAL -1
AUTO_REPREPARE 1
JVPLOGFILE /home/sinodbms/tmp/jvp.log
ENCRYPT_CIPHERS
ENCRYPT_MAC medium
ENCRYPT_CDR 0
ENCRYPT_HDR 0
ENCRYPT_SWITCH
ENCRYPT_SMX 0
CONSOLE /home/sinodbms/tmp/online.con
DEADLOCK_TIMEOUT 60 (s)
LOCKS 20000
ONDBSPACEDOWN 2
TXTIMEOUT 300 (s)
RA_PAGES
FILLFACTOR 90 (%)
OFF_RECVRY_THREADS 10
ON_RECVRY_THREADS 1
DATASKIP off
HETERO_COMMIT 0
SYSALARMPROGRAM /home/sinodbms/etc/evidence.sh
Validating PAGE_1CKPT & PAGE_2CKPT...
Using check point page PAGE_1CKPT.
Time stamp of checkpoint 0x2da2ad
Time of checkpoint 10/12/2023 23:19:18
Physical log begin address 1:263
Physical log size 25000 (p)
Physical log position at Ckpt 8514
Logical log unique identifier 31
Logical log position at Ckpt 0xf60018 (Page 3936, byte 24)
Checkpoint Interval 3055
DBspace descriptor page 1:4
Chunk descriptor page 1:7
Mirror chunk descriptor page 1:8
Log file number 1
Unique identifier 31
Log contains last checkpoint: Page 3936, byte 24
Log file flags 0x3 Log file in use
& Current log file
Physical location 1:25263
Log size 5000 (p)
Number pages used 3937
Date/Time file filled -
Time stamp -
Log file number 2
Unique identifier 26
Log file flags 0x5 Log file in use
& Log file has been backed up
Physical location 1:30263
Log size 5000 (p)
Number pages used 5000
Date/Time file filled 10/08/2023 01:11:01
Time stamp 0x25f988
Log file number 3
Unique identifier 27
Log file flags 0x5 Log file in use
& Log file has been backed up
Physical location 1:35263
Log size 5000 (p)
Number pages used 5000
Date/Time file filled 10/09/2023 01:00:00
Time stamp 0x27541a
Log file number 4
Unique identifier 28
Log file flags 0x5 Log file in use
& Log file has been backed up
Physical location 1:40263
Log size 5000 (p)
Number pages used 5000
Date/Time file filled 10/10/2023 01:00:00
Time stamp 0x28fb15
Log file number 5
Unique identifier 29
Log file flags 0x5 Log file in use
& Log file has been backed up
Physical location 1:45263
Log size 5000 (p)
Number pages used 5000
Date/Time file filled 10/11/2023 01:00:00
Time stamp 0x2aa1f0
Log file number 6
Unique identifier 30
Log file flags 0x5 Log file in use
& Log file has been backed up
Physical location 1:50263
Log size 5000 (p)
Number pages used 5000
Date/Time file filled 10/12/2023 01:00:01
Time stamp 0x2c4875
Validating PAGE_1DBSP & PAGE_2DBSP...
Using DBspace page PAGE_1DBSP.
DBspace number 1
DBspace name rootdbs
Flags 0x1 No mirror chunks
Number of chunks 1
First chunk 1
Date/Time created 09/17/2023 22:59:21
Partition table page number 14
Logical Log Unique Id 0
Logical Log Position 0x0
Oldest Logical Log Unique Id 31
Last Logical Log Unique Id 0
Expand Size (Chunk Create) 10.0%
Expand size (Chunk Extend) 10000k
DBspace archive status No archives have occurred.
Validating PAGE_1PCHUNK & PAGE_2PCHUNK...
Using primary chunk page PAGE_2PCHUNK.
Chunk number 1
Flags 0x20040 Chunk is online
Chunk path /home/sinodbms/chunks/rootdbs
Chunk offset 0 (p)
Chunk size 150000 (p)
Number of free pages 79205
DBspace number 1
Validating PAGE_1ARCH & PAGE_2ARCH...
Using archive page PAGE_1ARCH.
No archives have occurred.
DR has not been initialized.