Does anybody know what "read error on virtual disk" when starting
the dataserver (10.0.2 under SVR4.2MP 2.2 i386 (UnixWare)) really means?
It happend when I decreased our machine
memory from 32M to 24M, and the error disappeared when 8M were placed
back. The real problem is we have another machine with much greater hard
drive where the error persists also at 32M.

I found that dataserver works properly even at 16M core if no virtual
disks (including one containing the master database) are placed in raw
partitions, that is not recommended. Also, all the operations except the
dataserver start on raw device, show no errros, e.g. preparing the master
database by sybinit.

Can this problem be got past by tuning the kernel parameters? Or,
is this a Sybase bug?

dataserver launching.

TIA for sharing experience,

Alexei Medinets,
INT, Kiev, Ukraine

                        I. The Downfall Story

/usr/adm/log/osmlog:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
UnixWare 2.02 for the Intel386(tm) Family
...
total real memory        = 24698880
total available memory   = 22052864
...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

/etc/conf/cf.d/stune:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PHYSTOKVMEM     1
NUMREGPT        256
NUMSCOPT        32
SHMMNI  1000
SHMALL  2048
BUFHWM  1024
SFSNINODE       1200
VXFSNINODE      1200
DNLCSIZE        800
HCORLIM 0x7FFFFFFF
SCORLIM 0x7FFFFFFF
SSTKLIM 0x7FFFFFFF
HSTKLIM 0x7FFFFFFF
MAXUP   200
ARG_MAX 51200
HFNOLIM 400
SFNOLIM 400
NPROC   1600
SHMMAX  134217728
SHMSEG  15
SEMMNS  200
SEMMNI  100
SDATLIM 0x7FFFFFFF
HDATLIM 0x7FFFFFFF
SVMMLIM 0x7FFFFFFF
HVMMLIM 0x7FFFFFFF
SFSZLIM 0x7FFFFFFF
HFSZLIM 0x7FFFFFFF
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

/var/sybase/install/errorlog:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
...
00:96/01/28 18:47:33.47 kernel  SQL Server/10.0.2/P/Novell Intel/UnixWare 1.1/1/OPT/Wed May 24 14:30:10 PDT 1995
...
00:96/01/28 18:47:33.58 kernel  Using 400 file descriptors.
00:96/01/28 18:47:33.58 kernel  Network and device connection limit is 397.
00:96/01/28 18:47:33.85 kernel  Initializing virtual device 0, '/dev/rdsk/c0b0t0d0sc'
00:96/01/28 18:47:33.87 kernel  Virtual device 0 started using asynchronous i/o.
00:96/01/28 18:47:34.09 server  Number of buffers in buffer cache: 4123.
00:96/01/28 18:47:34.11 server  Number of proc buffers allocated: 1030.
00:96/01/28 18:47:34.12 server  Number of blocks left for proc headers: 1052.
00:96/01/28 18:47:37.46 server  Opening Master Database ...
00:96/01/28 18:47:38.04 kernel  sddone: read error on virtual disk 0 block 284:
00:96/01/28 18:47:38.08 kernel  sddone: Invalid argument
00:96/01/28 18:47:38.09 server  No such message
00:96/01/28 18:47:38.12 kernel  curdb = 0 pstat = 0x40 lasterror = 8204
00:96/01/28 18:47:38.13 kernel  preverror = 0 transtate = 1
00:96/01/28 18:47:38.13 kernel  curcmd = 0 program =
....
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

                        II. The Success Story

/usr/adm/log/osmlog:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
UnixWare 2.02 for the Intel386(tm) Family
....
total real memory        = 33087488
total available memory   = 30236672
....
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

/var/sybase/install/errorlog:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
....
00:96/01/28 19:09:55.62 kernel  Using 400 file descriptors.
00:96/01/28 19:09:55.63 kernel  Network and device connection limit is 397.
00:96/01/28 19:09:56.00 kernel  Initializing virtual device 0, '/dev/rdsk/c0b0t0d0sc'
00:96/01/28 19:09:56.02 kernel  Virtual device 0 started using asynchronous i/o.
00:96/01/28 19:09:56.24 server  Number of buffers in buffer cache: 4123.
00:96/01/28 19:09:56.26 server  Number of proc buffers allocated: 1030.
00:96/01/28 19:09:56.26 server  Number of blocks left for proc headers: 1052.
00:96/01/28 19:09:57.45 server  Opening Master Database ...
00:96/01/28 19:09:59.78 server  Loading SQL Server's default sort order and character set
....
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~