ESXi storage

[yatta201110141]

Hello everyone,

I'm planning to add some servers as i'm running out of resources.

I did some research and have choosen 2 options of storage:

- local - but it will run out of space rather quick.

- iscsi storage.

Hardware will be like this:

2 dell r510 servers with 3 local hdd 300GB connected via 2 3com L3 switches with Dell MD3200i array with 12 2TB 7200 hdd.

I do prefer iscsi storage, but i wonder about efficiency of this solution.

So few questions :

- will isci manage running machines stored on array?

- does ESXi offers that kind of storage?

- any benchmarks of storage local vs iscsi?

Thanks in advance,

Peter

[idle-jam]

1) yes, VM can run on on iSCSI

2) yes, ESXi supports on iSCSI

3) generally the performance of the disk compromise of number of disks & cache. chance it would be more because local hdd could only consist of just few units only.

[gdavid]

Just food for thought, but be careful when running on large SATA drives

2TB 7200 drives are not really enterprise worthy, you should consider how much disk performance your virtual machines will need. (ie. SQL)

we had problems with the HP 2000i G1 and 1TB drives (horrible solution)

newer models 2312i G2 and p2000 G3 are better, but i only buy 15k SAS drives now.

i use a RAID 50 with 16 600GB 15k SAS drives

RAID 0

|

L RAID 5 (8 Drives)

|

L RAID 5 (8 Drives)

works well for me so far.

happy VM'ing.

[DSTAVERT]

When creating LUNs for ESX(i) remember that the largest LUN size must be slightly less than 2TB. RAID 10 will give you best performance.

A 3 disk RAID 5 array is a poor performer. If you need the performance of local disks add a few more.

[bulletprooffool]

Peter - the benefits of using networked storage far outweigh the downsides.

Performance on your iSCSI solution is unlikely to be much worse than the local storage and VMs on local storage will be lost immediately if an ESX host goes down, where network storage can be attached to another host and the VM resumed (assuming you do not have a VC etc)

[yatta201110141]

Thank You all for the answers and suggestion.

Regarding DSTAVERT post - i'm not planning use of local hdd for VM purposes. But maybe it is a good idea to put 4 hdd in raid 10 locally to improve server efficiency?

After gdavid post i'm little confused. What about such setup - 6 x 600GB 15k sas in raid  ( which Raid 5 or 10), with 6 x 2TB 7.2k ?

[DSTAVERT]

If you aren't using the local storage for VMs is this for installing ESXi? If this is for ESXi then don't waste your money for disks. ESXi install takes less than 1GB and 4GB for scratch space. It loads directly into RAM and only writes to disk once per hour backing up the configuration to the alternate boot partition.  I would install to the internal USB or SD card module.

RAID 10 will give the best performance for the datastores. SAS in RAID 5 will be better than SATA RAID 10

[Josh26]

yatta wrote:

After gdavid post i'm little confused. What about such setup - 6 x 600GB 15k sas in raid  ( which Raid 5 or 10), with 6 x 2TB 7.2k ?

The RAID level will be almost insignificant next to a comparison of 7.2K drives vs 15K drives - which will be a major difference. Since the latter almost certainly means moving to SATA, there will be issues beyond performance to consider too, such as reliability.