Enabling or disabling file system caching may result in
tablespace being inaccessible
The ALTER TABLESPACE [NO] FILE SYSTEM CACHING statement can be
used to enable or disable file system caching for the given
tablespace. However, this operation may not be fully supported
by the underlying file system. For example, if the user alters a
tablespace to use NO FILE SYSTEM CACHING on a VxFS file system
without CIO capability, the tablespace alteration will still
succeed. However, subsequent attempts to use the altered
tablespace will result in the tablespace being marked offline,
as well as being in rollforward-pending state. Further attempts
to switch the tablespace into an online state will result in the
database being marked bad. The following symptoms will be seen
in the DB2 diagnostic log:
2010-05-20-18.37.32.778048-300 E90732A554 LEVEL: Warning
(OS)
PID : 2547828 TID : 1 PROC :
db2agent (SAMPLE) 0
INSTANCE: db2inst1 NODE : 000 DB :
SAMPLE
APPHDL : 0-1290 APPID: C6BB721A.DE62.1AE940225623
AUTHID : DB2INST1
FUNCTION: DB2 UDB, oper system services, sqloopenp, probe:80
MESSAGE : ZRC=0x8300007C=-2097151876
CALLED : OS, -, open
OSERR : ENOTSUP (124) "Unsupported attribute value"
DATA #1 : File name, 60 bytes
/home/db2inst1/db2inst1/NODE0000/SAMPLE/T0000018/C0000008.LRG
When using the Veritas Storage Foundation file system (VxFS),
concurrent I/O (CIO) capability needs to be available in order
to take advantage of NO FILE SYSTEM CACHING on a tablespace. CIO
capability is available for VxFS only with the appropriate
license. Another example is an attempt to disable file system
caching for non-SCIS devices on Linux for S/390, please see APAR
LI72704 for more detail.
The purpose of this fix is to:
Add an early detection of an unsupported combination of file
system caching/file system type to the ALTER TABLESPACE
statement. When a problem is found when changing file system
caching, SQL0298N "Bad container path" will be returned, ALTER
TABLESPACE will be canceled, and the caching option will remain
unchanged. |
****************************************************************
* USERS AFFECTED: *
* Customers altering tablespace file system caching *
****************************************************************
* PROBLEM DESCRIPTION: *
* Regarding the file system caching of DB2 tablespace there *
* are some unsupported underlying file system combination *
* as described the APAR error description. Without the fix *
* of this APAR, user who is trying to alter tablespace with *
* those unsupported file system combination will experience *
* tablespace to go offline as well as rollforward-pending *
* state. Further attempts to switch the tablesapce into an *
* online state will result in database being marked bad. *
****************************************************************
* RECOMMENDATION: *
* To avoid experiencing this issue user can upgrade to DB2 *
* Version V9.1 fix pak 10 or, use the guideline provided *
* under LOCAL FIX *
**************************************************************** |
