Hi, Sean, I saw the PR https://github.com/apache/cloudstack/pull/3194 which seems covers one of the bugs. Haven't had enough time to dive into the code to do a review for snapshot-related workflows, but looks like this PR does the right thing. Hope it will be added to 4.11.3.
чт, 28 февр. 2019 г. в 17:02, Sean Lair <sl...@ippathways.com>: > Hi Ivan, I wanted to respond here and see if you published a PR yet on > this. > > This is a very scary issue for us as customer can snapshot their volumes > and end up causing corruption - and they blame us. It's already happened - > luckily we had Storage Array level snapshots in place as a safety net... > > Thanks!! > Sean > > -----Original Message----- > From: Ivan Kudryavtsev [mailto:kudryavtsev...@bw-sw.com] > Sent: Sunday, January 27, 2019 7:29 PM > To: users <users@cloudstack.apache.org>; cloudstack-fan < > cloudstack-...@protonmail.com> > Cc: dev <d...@cloudstack.apache.org> > Subject: Re: Snapshots on KVM corrupting disk images > > Well, guys. I dived into CS agent scripts, which make volume snapshots and > found there are no code for suspend/resume and also no code for qemu-agent > call fsfreeze/fsthaw. I don't see any blockers adding that code yet and try > to add it in nearest days. If tests go well, I'll publish the PR, which I > suppose could be integrated into 4.11.3. > > пн, 28 янв. 2019 г., 2:45 cloudstack-fan > cloudstack-...@protonmail.com.invalid: > > > Hello Sean, > > > > It seems that you've encountered the same issue that I've been facing > > during the last 5-6 years of using ACS with KVM hosts (see this > > thread, if you're interested in additional details: > > https://mail-archives.apache.org/mod_mbox/cloudstack-users/201807.mbox > > /browser > > ). > > > > I'd like to state that creating snapshots of a running virtual machine > > is a bit risky. I've implemented some workarounds in my environment, > > but I'm still not sure that they are 100% effective. > > > > I have a couple of questions, if you don't mind. What kind of storage > > do you use, if it's not a secret? Does you storage use XFS as a > filesystem? > > Did you see something like this in your log-files? > > [***.***] XFS: qemu-kvm(***) possible memory allocation deadlock size > > 65552 in kmem_realloc (mode:0x250) > > [***.***] XFS: qemu-kvm(***) possible memory allocation deadlock size > > 65552 in kmem_realloc (mode:0x250) > > [***.***] XFS: qemu-kvm(***) possible memory allocation deadlock size > > 65552 in kmem_realloc (mode:0x250) > > Did you see any unusual messages in your log-file when the disaster > > happened? > > > > I hope, things will be well. Wish you good luck and all the best! > > > > > > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ > > On Tuesday, 22 January 2019 18:30, Sean Lair <sl...@ippathways.com> > wrote: > > > > > Hi all, > > > > > > We had some instances where VM disks are becoming corrupted when > > > using > > KVM snapshots. We are running CloudStack 4.9.3 with KVM on CentOS 7. > > > > > > The first time was when someone mass-enabled scheduled snapshots on > > > a > > lot of large number VMs and secondary storage filled up. We had to > > restore all those VM disks... But believed it was just our fault with > > letting secondary storage fill up. > > > > > > Today we had an instance where a snapshot failed and now the disk > > > image > > is corrupted and the VM can't boot. here is the output of some commands: > > > > > > > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ------------------------------------------------ > > > > > > [root@cloudkvm02 c3be0ae5-2248-3ed6-a0c7-acffe25cc8d3]# qemu-img > > > check > > ./184aa458-9d4b-4c1b-a3c6-23d28ea28e80 > > > qemu-img: Could not open './184aa458-9d4b-4c1b-a3c6-23d28ea28e80': > > > Could > > not read snapshots: File too large > > > > > > [root@cloudkvm02 c3be0ae5-2248-3ed6-a0c7-acffe25cc8d3]# qemu-img > > > info > > ./184aa458-9d4b-4c1b-a3c6-23d28ea28e80 > > > qemu-img: Could not open './184aa458-9d4b-4c1b-a3c6-23d28ea28e80': > > > Could > > not read snapshots: File too large > > > > > > [root@cloudkvm02 c3be0ae5-2248-3ed6-a0c7-acffe25cc8d3]# ls -lh > > ./184aa458-9d4b-4c1b-a3c6-23d28ea28e80 > > > -rw-r--r--. 1 root root 73G Jan 22 11:04 > > ./184aa458-9d4b-4c1b-a3c6-23d28ea28e80 > > > > > > > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ----------------------------------------------------------- > > > > > > We tried restoring to before the snapshot failure, but still have > > strange errors: > > > > > > > > ---------------------------------------------------------------------- > > -------------- > > > > > > [root@cloudkvm02 c3be0ae5-2248-3ed6-a0c7-acffe25cc8d3]# ls -lh > > ./184aa458-9d4b-4c1b-a3c6-23d28ea28e80 > > > -rw-r--r--. 1 root root 73G Jan 22 11:04 > > ./184aa458-9d4b-4c1b-a3c6-23d28ea28e80 > > > > > > [root@cloudkvm02 c3be0ae5-2248-3ed6-a0c7-acffe25cc8d3]# qemu-img > > > info > > ./184aa458-9d4b-4c1b-a3c6-23d28ea28e80 > > > image: ./184aa458-9d4b-4c1b-a3c6-23d28ea28e80 > > > file format: qcow2 > > > virtual size: 50G (53687091200 bytes) disk size: 73G > > > cluster_size: 65536 > > > Snapshot list: > > > ID TAG VM SIZE DATE VM CLOCK > > > 1 a8fdf99f-8219-4032-a9c8-87a6e09e7f95 3.7G 2018-12-23 11:01:43 > > 3099:35:55.242 > > > 2 b4d74338-b0e3-4eeb-8bf8-41f6f75d9abd 3.8G 2019-01-06 11:03:16 > > 3431:52:23.942 > > > Format specific information: > > > compat: 1.1 > > > lazy refcounts: false > > > > > > [root@cloudkvm02 c3be0ae5-2248-3ed6-a0c7-acffe25cc8d3]# qemu-img > > > check > > ./184aa458-9d4b-4c1b-a3c6-23d28ea28e80 > > > tcmalloc: large alloc 1539750010880 bytes == (nil) @ 0x7fb9cbbf7bf3 > > 0x7fb9cbc19488 0x7fb9cb71dc56 0x55d16ddf1c77 0x55d16ddf1edc > > 0x55d16ddf2541 0x55d16ddf465e 0x55d16ddf8ad1 0x55d16de336db > > 0x55d16de373e6 0x7fb9c63a3c05 0x55d16ddd9f7d > > > No errors were found on the image. > > > > > > [root@cloudkvm02 c3be0ae5-2248-3ed6-a0c7-acffe25cc8d3]# qemu-img > > snapshot -l ./184aa458-9d4b-4c1b-a3c6-23d28ea28e80 > > > Snapshot list: > > > ID TAG VM SIZE DATE VM CLOCK > > > 1 a8fdf99f-8219-4032-a9c8-87a6e09e7f95 3.7G 2018-12-23 11:01:43 > > 3099:35:55.242 > > > 2 b4d74338-b0e3-4eeb-8bf8-41f6f75d9abd 3.8G 2019-01-06 11:03:16 > > 3431:52:23.942 > > > > > > > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > ---------------------------------------------------------------------- > > --------------------------------------------------------------- > > > > > > Everyone is now extremely hesitant to use snapshots in KVM.... We > > > tried > > deleting the snapshots in the restored disk image, but it errors out... > > > > > > Does anyone else have issues with KVM snapshots? We are considering > > > just > > disabling this functionality now... > > > > > > Thanks > > > Sean > > > > > > > -- With best regards, Ivan Kudryavtsev Bitworks LLC Cell RU: +7-923-414-1515 Cell USA: +1-201-257-1512 WWW: http://bitworks.software/ <http://bw-sw.com/>
