10:54 a.m.
On 03/01/2011 08:48 AM, Philipp Hahn wrote:
Currently a single storage volume with a broken backing file will
disable the
whole storage pool. This can happen when the backing file is on some
unavailable network storage or if the backing volume is deleted, while the
storage volumes using it remain.
Since the storage pool can not be re-activated, re-creating the missing
or deleting the now useless volumes using libvirt only is not possible.
Fixing this is a little bit tricky:
1. virStorageBackendProbeTarget() only detects the missing backing file,
if the backing file format is not explicitly specified. If the
backing file is created using
kvm-img create -f qcow2 -o backing_fmt=qcow2,backing_file=... ...
no error is detected at this stage.
The new return code -3 signals that the backing file could not be
opened.
2. The backingStore.format must be >= 0, since values < 0 would break
virStorageVolTargetDefFormat() when dumping the XML data such as
<format type='...'/>
Because of this the format is faked as VIR_STORAGE_FILE_RAW.
3. virStorageBackendUpdateVolTargetInfo() always opens the backing file
and thus always detects a missing backing file.
Since it "only" updates the capacity, allocation, owner, group, mode
and SELinux label, just ignore errors at this stage, print an error
message and continue.
4. Using vol-dump on a broken volume still doesn't work, but at leas
s/leas/least/
vol-destroy and pool-refresh do work now.
Thanks for the ping, and yes, this version looks like it fixes the
feedback from earlier review. Sorry for the delay review.
To reproduce:
dir=$(mktemp -d)
virsh pool-create-as tmp dir '' '' '' ''
"$dir"
virsh vol-create-as --format qcow2 tmp back 1G
virsh vol-create-as --format qcow2 --backing-vol-format qcow2 --backing-vol back tmp
cow 1G
virsh vol-delete --pool tmp back
virsh pool-refresh tmp
After the last step, the pool will be gone (because it was not persistent). As
long as the now broken image stays in the directory, you will not be able to
re-create or re-start the pool.
Even more awesome when you do this :)
@@ -665,8 +680,15 @@ virStorageBackendFileSystemRefresh(virConnectPtr
conn ATTRIBUTE_UNUSED,
if (virStorageBackendUpdateVolTargetInfo(&vol->backingStore,
NULL,
NULL) < 0) {
- VIR_FREE(vol->backingStore.path);
- goto cleanup;
+ /* The backing file is currently unavailable, the capacity,
+ * allocation, owner, group and mode are unknown. Just log the
+ * error an continue.
+ * Unfortunately virStorageBackendProbeTarget() might already
+ * have logged a similar message for the same problem, but only
+ * if AUTO format detection was used. */
+ virStorageReportError(VIR_ERR_INTERNAL_ERROR,
+ _("cannot probe backing volume info:
%s"),
+ vol->backingStore);
Oops:
CC libvirt_driver_storage_la-storage_backend_fs.lo
cc1: warnings being treated as errors
storage/storage_backend_fs.c: In function
'virStorageBackendFileSystemRefresh':
storage/storage_backend_fs.c:688:17: error: format '%s' expects type
'char *', but argument 8 has type 'virStorageVolTarget' [-Wformat]
ACK with that fixed, so I squashed this and pushed:
diff --git i/src/storage/storage_backend_fs.c
w/src/storage/storage_backend_fs.c
index e629219..0a6b074 100644
--- i/src/storage/storage_backend_fs.c
+++ w/src/storage/storage_backend_fs.c
@@ -1,7 +1,7 @@
/*
* storage_backend_fs.c: storage backend for FS and directory handling
*
- * Copyright (C) 2007-2010 Red Hat, Inc.
+ * Copyright (C) 2007-2011 Red Hat, Inc.
* Copyright (C) 2007-2008 Daniel P. Berrange
*
* This library is free software; you can redistribute it and/or
@@ -687,7 +687,7 @@ virStorageBackendFileSystemRefresh(virConnectPtr
conn ATTRIBUTE_UNUSED,
* if AUTO format detection was used. */
virStorageReportError(VIR_ERR_INTERNAL_ERROR,
_("cannot probe backing volume
info: %s"),
- vol->backingStore);
+ vol->backingStore.path);
}
}
--
Eric Blake eblake(a)redhat.com +1-801-349-2682
Libvirt virtualization library http://libvirt.org