Re: [ovirt-users] Maximum storage per VM?
On Tue, Oct 10, 2017 at 3:31 PM, Dmitri Chebotarov wrote: > Good Morning > > I'm using virtio-scsi (also tried virtio), not using IDE (doesn't IDE have > 4 devices limit? it's long time since I used IDE...). > > This is for servers hosting own/nextCloud and Samba for a small/medium > groups with large datasets (60-80TB) per server. > > If ovirt-scsi allows to attach >20 disks then it meets my needs in this > case. Thank you. > > The reason I opted for LVM is performance. It's so much faster with LVM > and striped volumes compared to a single large disk. I'm seeing very high > 'iowait' numbers (to the point when VM is unresponsive) when I'm dumping > large amount of data to a single disk. But with LVM striped volumes > 'iowait' at around ~20% and I can get to ~750MB/s in the same environment > (same config with single disk is ~160MB/s). > Interesting. What version of Gluster are you using? Are you using sharding? What's the underlying storage for Gluster and how is it set up? > > Also, healing a single large disk on gluster takes ages (I'm using erasure > coded volumes) . > Sharding and newer versions of Gluster should help here. Y. > > > Thank you, > -- > Dmitri Chebotarov. > George Mason University, > 4400 University Drive, > Fairfax, VA, 22030 > GPG Public key# 5E19F14D: [https://goo.gl/SlE8tj] > > > ________________________ > From: Yaniv Kaul > Sent: Tuesday, October 10, 2017 4:03:08 AM > To: Dmitri Chebotarov > Cc: users@ovirt.org > Subject: Re: [ovirt-users] Maximum storage per VM? > > On Fri, Oct 6, 2017 at 10:24 PM, Dmitri Chebotarov <mailto:dcheb...@gmu.edu>> wrote: > Hello > > I'm trying to find any info on how much storage I can attach to a VM. > > Is there a recommended/maximum for number of disks and maximum disk size? > > Disk count depends on the interface - IDE - very few, virtio- 20-something > (depends on the number of PCI slots available), virtio-SCSI - more. > What is the use case? > > > I'm using GlusterFS as backend storage for the cluster. > > The VM uses LVM (/w striped volumes) to manage attached disks. > > Aren't you having layers over layers over layers? Is that the optimal > arrangement? > (Again, would be interesting to understand the use case to better provide > information). > Y. > > > Thank you, > -- > Dmitri Chebotarov. > George Mason University, > 4400 University Drive, > Fairfax, VA, 22030 > GPG Public key# 5E19F14D: [https://goo.gl/SlE8tj] > > ___ > Users mailing list > Users@ovirt.org<mailto:Users@ovirt.org> > http://lists.ovirt.org/mailman/listinfo/users > > ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] Maximum storage per VM?
Good Morning I'm using virtio-scsi (also tried virtio), not using IDE (doesn't IDE have 4 devices limit? it's long time since I used IDE...). This is for servers hosting own/nextCloud and Samba for a small/medium groups with large datasets (60-80TB) per server. If ovirt-scsi allows to attach >20 disks then it meets my needs in this case. Thank you. The reason I opted for LVM is performance. It's so much faster with LVM and striped volumes compared to a single large disk. I'm seeing very high 'iowait' numbers (to the point when VM is unresponsive) when I'm dumping large amount of data to a single disk. But with LVM striped volumes 'iowait' at around ~20% and I can get to ~750MB/s in the same environment (same config with single disk is ~160MB/s). Also, healing a single large disk on gluster takes ages (I'm using erasure coded volumes) . Thank you, -- Dmitri Chebotarov. George Mason University, 4400 University Drive, Fairfax, VA, 22030 GPG Public key# 5E19F14D: [https://goo.gl/SlE8tj] From: Yaniv Kaul Sent: Tuesday, October 10, 2017 4:03:08 AM To: Dmitri Chebotarov Cc: users@ovirt.org Subject: Re: [ovirt-users] Maximum storage per VM? On Fri, Oct 6, 2017 at 10:24 PM, Dmitri Chebotarov mailto:dcheb...@gmu.edu>> wrote: Hello I'm trying to find any info on how much storage I can attach to a VM. Is there a recommended/maximum for number of disks and maximum disk size? Disk count depends on the interface - IDE - very few, virtio- 20-something (depends on the number of PCI slots available), virtio-SCSI - more. What is the use case? I'm using GlusterFS as backend storage for the cluster. The VM uses LVM (/w striped volumes) to manage attached disks. Aren't you having layers over layers over layers? Is that the optimal arrangement? (Again, would be interesting to understand the use case to better provide information). Y. Thank you, -- Dmitri Chebotarov. George Mason University, 4400 University Drive, Fairfax, VA, 22030 GPG Public key# 5E19F14D: [https://goo.gl/SlE8tj] ___ Users mailing list Users@ovirt.org<mailto:Users@ovirt.org> http://lists.ovirt.org/mailman/listinfo/users ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] Maximum storage per VM?
On Fri, Oct 6, 2017 at 10:24 PM, Dmitri Chebotarov wrote: > Hello > > I'm trying to find any info on how much storage I can attach to a VM. > > Is there a recommended/maximum for number of disks and maximum disk size? > Disk count depends on the interface - IDE - very few, virtio- 20-something (depends on the number of PCI slots available), virtio-SCSI - more. What is the use case? > > I'm using GlusterFS as backend storage for the cluster. > > The VM uses LVM (/w striped volumes) to manage attached disks. > Aren't you having layers over layers over layers? Is that the optimal arrangement? (Again, would be interesting to understand the use case to better provide information). Y. > > Thank you, > -- > Dmitri Chebotarov. > George Mason University, > 4400 University Drive, > Fairfax, VA, 22030 > GPG Public key# 5E19F14D: [https://goo.gl/SlE8tj] > > ___ > Users mailing list > Users@ovirt.org > http://lists.ovirt.org/mailman/listinfo/users > ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] Maximum storage per VM?
Hi Kasturi The data disks are located on a stand-alone Gluster cluster, distributed-dispersed volume. Is there a limit in this case? I tested with up to 8x3TB disks and everything looks good so far. I'm trying to find out what's the maximum supported disks count and size w/o actually creating/attaching disks. I cannot find the info in oVirt/RHEV docs... Thank you, -- Dmitri Chebotarov. George Mason University, 4400 University Drive, Fairfax, VA, 22030 GPG Public key# 5E19F14D: [https://goo.gl/SlE8tj] From: Kasturi Narra Sent: Monday, October 9, 2017 7:59:34 AM To: Dmitri Chebotarov Cc: users@ovirt.org Subject: Re: [ovirt-users] Maximum storage per VM? Hi Dmitri, If the vms are created on a Hyperconverged setup then the max disk size recommended is 2TB. Thanks kasturi. On Sat, Oct 7, 2017 at 12:54 AM, Dmitri Chebotarov mailto:dcheb...@gmu.edu>> wrote: Hello I'm trying to find any info on how much storage I can attach to a VM. Is there a recommended/maximum for number of disks and maximum disk size? I'm using GlusterFS as backend storage for the cluster. The VM uses LVM (/w striped volumes) to manage attached disks. Thank you, -- Dmitri Chebotarov. George Mason University, 4400 University Drive, Fairfax, VA, 22030 GPG Public key# 5E19F14D: [https://goo.gl/SlE8tj] ___ Users mailing list Users@ovirt.org<mailto:Users@ovirt.org> http://lists.ovirt.org/mailman/listinfo/users ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] Maximum storage per VM?
Hi Dmitri, If the vms are created on a Hyperconverged setup then the max disk size recommended is 2TB. Thanks kasturi. On Sat, Oct 7, 2017 at 12:54 AM, Dmitri Chebotarov wrote: > Hello > > I'm trying to find any info on how much storage I can attach to a VM. > > Is there a recommended/maximum for number of disks and maximum disk size? > > I'm using GlusterFS as backend storage for the cluster. > > The VM uses LVM (/w striped volumes) to manage attached disks. > > Thank you, > -- > Dmitri Chebotarov. > George Mason University, > 4400 University Drive, > Fairfax, VA, 22030 > GPG Public key# 5E19F14D: [https://goo.gl/SlE8tj] > > ___ > Users mailing list > Users@ovirt.org > http://lists.ovirt.org/mailman/listinfo/users > ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
[ovirt-users] Maximum storage per VM?
Hello I'm trying to find any info on how much storage I can attach to a VM. Is there a recommended/maximum for number of disks and maximum disk size? I'm using GlusterFS as backend storage for the cluster. The VM uses LVM (/w striped volumes) to manage attached disks. Thank you, -- Dmitri Chebotarov. George Mason University, 4400 University Drive, Fairfax, VA, 22030 GPG Public key# 5E19F14D: [https://goo.gl/SlE8tj] ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users