Large LV, expereinces and recommendations?

[Tymish]

I'm about to put a pair of 16TB units online. Each has three 3ware H/W RAIDs.
2x4.5 TB and 1x6.2TB
Created a VG using one 4.5 and 1 6.2 Keeping the last 4.5TB as expansion space.

I'll be using these as a NAS pair right now.

Half the users will be mapped to unit 1 with data replication to unit2 and the other half mapped to unit2 with data replicated on unit1.

So I get some load balancing and hot backup as well. Should one unit have a disastrous failure I just map those users over to unit2 & allow access.

Now my question.

Is there any reason I shouldn't create a single 10+ TB LV?

[To-M]

Unless you need a separate RAID set for a specific reason and separate cache for the RAID sets to keep spindle count low then no. Many engineers will not put more then 22-24 drives in a RAID 5 or 6 but with RAID 10 they will and some wont place more then 12-16 drives on a RAID 5 or 6.

[Tymish]

In my case I have three RAID 5 units with hot spares in each system. Two 11 drive and one 15 drive RAID I'm combining two of them into an 11TB VG. Then I want to create a single 10TB LV for my storage volume.

[Tymish]

So having a 10TB LV shouldn't be an issue then? What about FSCK? That could take a looong time. How does DSS handle that?

[To-M]

10TB is fine - we format the disks to xsf when you create the volume group. If iSCSI LV is created then the OS's will do the rest.

[silicon]

This may be out of date now, but from a previous nightmare we had with DSS, make sure you are running in 64bit mode and have lots of Ram, otherwise fsck etc. can never complete a scan on a large volume! Cheers.