SAS Multipath / Shared SAS storage?

[Merundius]

Hi,

We plan to setup a cluster with

2x HP DL360 server
1x HP MSA2040 SAS storage array

Each of the two controllers of the MSA2040 should be connected directly via SAS to an HBA on the nodes running on the DL360 (see attached img / h t t p ://h20564.www2.hpe.com/hpsc/doc/public/imageServlet?DOCID=emr_na-c03823462-2/c05143178.gif)

So we can save 2 storage-switches which would be needed for keeping up redundancy.

My questions to the community:

• Does Proxmox support directly attached shared storage?
• Is this multipath setup recommended for getting a single shared storage running on both servers?
• What about snapshots and online migration? Which filesystem do you recommend in this case?
• Does anyone have some performance experiences regarding the use of SSDs vs SAS HDD drives?

Thank you for sharing your knowledge!

 

[udo]

Hi,

We plan to setup a cluster with

2x HP DL360 server
1x HP MSA2040 SAS storage array

Each of the two controllers of the MSA2040 should be connected directly via SAS to an HBA on the nodes running on the DL360 (see attached img / h t t p ://h20564.www2.hpe.com/hpsc/doc/public/imageServlet?DOCID=emr_na-c03823462-2/c05143178.gif)

So we can save 2 storage-switches which would be needed for keeping up redundancy.

My questions to the community:

• Does Proxmox support directly attached shared storage?

Hi,
yes is supported.

• Is this multipath setup recommended for getting a single shared storage running on both servers?

better (about failure) would use sas-multipath with an connection to each controller. But if one controller die, your VMs can run on the other node.

• What about snapshots and online migration? Which filesystem do you recommend in this case?

No filesystem -> lvm! Online migration work very well - snapshots not (except manual lvm-snapshots - but this is for special use only).

• Does anyone have some performance experiences regarding the use of SSDs vs SAS HDD drives?

Thank you for sharing your knowledge!

don't know hp-stuff, but with the right SSDs you will be very fast if your controller isn't an brake.

Udo

 

[Merundius]

Hi Udo,

Thank you for those informations!

Does the included vzdump backup work with shared lvm storage work as fine as local storage while doing online-backups?

What happens if you start backup jobs via snapshots on separate hosts on the same LVM based shared storage (assumed enough free space in the lv)?

Many regards,

Martin

 

[udo]

Hi Udo,

Thank you for those informations!

Does the included vzdump backup work with shared lvm storage work as fine as local storage while doing online-backups?

What happens if you start backup jobs via snapshots on separate hosts on the same LVM based shared storage (assumed enough free space in the lv)?

Many regards,

Martin

Hi Martin,
backup work and different nodes are no problem because every vm disk is an LV and pve handle the logging.

Udo

 

[adamb]

Hi,

We plan to setup a cluster with

2x HP DL360 server
1x HP MSA2040 SAS storage array

Each of the two controllers of the MSA2040 should be connected directly via SAS to an HBA on the nodes running on the DL360 (see attached img / h t t p ://h20564.www2.hpe.com/hpsc/doc/public/imageServlet?DOCID=emr_na-c03823462-2/c05143178.gif)

So we can save 2 storage-switches which would be needed for keeping up redundancy.

My questions to the community:

• Does Proxmox support directly attached shared storage?
• Is this multipath setup recommended for getting a single shared storage running on both servers?
• What about snapshots and online migration? Which filesystem do you recommend in this case?
• Does anyone have some performance experiences regarding the use of SSDs vs SAS HDD drives?

Thank you for sharing your knowledge!

Our previous configuration we sold to clients was 2x HP DL 380's with a HP 2040 MSA SAS enclosure. Each DL 380 had 2x HBA's and connected to each raid controller of the central storage just like you are looking at. We used multipath and LVM ontop of the multipath block devices.

Online migration will work with no issues.

Software snapshots at the proxmox level won't really be an option. Hardware snapshots on the MSA 2040 might work, but the 2040 is extremely limited in write performance once a snapshot has been taken. We moved away from the P2000/MSA 2040 for a number of reasons. Everything from performance issues, random odd bugs in the CLI and GUI, and at one clients site we lost an entire raid volume while doing a firmware update. To say I am not a huge fan of the the P2000/MSA line is an understatement.

Its pretty good at sequential IO, but random IO its not that great. I know it does support SSD for cache, but the price they put on those SSD's is just crazy.

 

[Merundius]

Hi Adam,

Thanks for sharing your experiences - you said you moved away from the MSA - is there a more solid shared storage solution? Or did you go back to local storage?

Many regards,

Martin

 

[adamb]

Hi Adam,

Thanks for sharing your experiences - you said you moved away from the MSA - is there a more solid shared storage solution? Or did you go back to local storage?

Many regards,

Martin

We ended up going with Nimble storage and haven't looked back. One of the best decisions we made. Funny enough, they are now owned by HPE. Its going to cost a little more, but I can't stress enough on how much better of a product it is.

There are also a ton of other options out there.

The MSA line is ok, but its nothing but re-branded dothill hardware. HP tech doesn't even know the product all that well.