Red Hat ENTERPRISE LINUX 5.5 - S 2010, Manual

Page: 149 / 470

RHSA-2010:0271: Important security, bug fix and enhancement update
139
• The
qemu-img
command failed to copy a RAW image to a Fibre Channel storage device. The
qemu-image
command can now copy, convert and create images on Fibre Channel storage
devices. (
BZ#511072
1263
)
• Storage I/O errors were processed out of order causing the guest to change state or crash
unexpectedly. The guest state handlers now process storage I/O errors in the proper order.
(
BZ#514522
1264
)
• A guest would occasionally not accept keystrokes or mouse clicks after rebooting. The updated
package resolves this issue and user interactions are accepted after repeatedly rebooting guests.
(
BZ#515275
1265
)
• In rare instances, certain virtualized guests could lock up while requesting a
raw_pread
system
call. The offset was larger than the file size of the read failures which causes the system to
infinitely loop I/O requests. This could, in certain circumstances lead to file system corruption on
virtualized guests. The updated pacakges add a result test which prevents the infinite request loop.
(
BZ#515655
1266
)
• The guest could change the QXL device ROM which could result in memory corruption. The
updated packages prevent the guest from modifying the QXL device ROM. (
BZ#537888
1267
)
• The MRS storage array (
msrs
) in
kvm_arch_save_regs()
function. The array was sized too
small for the function and may cause stack corruption. (
BZ#528917
1268
)
• Incorrectly handled I/O errors could cause guests file system corruption when using the para-
virtualized block drivers and IDE emulation of NFS storage. The updated packages resolve
this issue and host I/O errors will pause the guest instead of causing file system corruption.
(
BZ#531827
1269
)
• With Red Hat Enterprise Virtualization, the
virtio_blk_dma_restart_bh()
function previously
handled write errors. The function was not updated for this, causing read errors to be resubmitted as
writes. This caused guest image corruption in some cases.
Additionally, the return values of the
bdrv_aio_write()
and
bdrv_aio_read()
functions were
ignored. If an immediate failure occurred in one of these functions, errors would be missed and the
guest could hang or read corrupted data. (
BZ#552487
1270
)
• with Red Hat Enterprise Virtualization, guests continued to run after encountering disk read
errors. This could have caused guest file systems to corrupt (but not the host's), notably in
environments that use networked storage. With this update, the
qemu-kvm
command's
-drive
"werror=stop"
option now applies not only to write errors but also to read errors. When using this
option, guests will pause on disk read and write errors.
By default, guests managed by Red Hat Enterprise Virtualization use the
"werror=stop"
option.
This option is not used by default for guests managed by libvirt. (
BZ#533390
1271
)
• KVM would crash or fail to boot when attempting to assign 64GB of memory to 32-bit guests using
PAE. KVM now supports addressing up to 48 bits of physical memory with PAE. (
BZ#516545
1272
)
• Windows Server 2003 32-bit guests assigned more than 4GB of RAM would crash after rebooting
the guest. The updated packages resolve this issue and Windows Server 2003 32-bit guests can
be assigned more than 4GB of RAM. 32-bit guests may not be able to use more than 4GB of RAM,
refer to the guest operating system's documentation. (
BZ#516762
1273
)