RAID-5 expansion

[mheloy]

Hi Gurus,

I'm planning to expand a filesystem that has a RAID 5 protection using SDS. What things should I consider before doing the expansion? What are the limitation of expanding a RAID 5? Can I just expand and expand a RAID5?

Thanks gurus!

 

[daFranze]

no, a RAID5 is not expandable; if you need more space you will have to
- backup data
- reorganize your disks
- create FS
- restore data

afaik: Veritas VM GUI offers a "resize" of a RAID5, but in fact, it just creates a concatenation of two RAID5s

Best Regards, Franz
--
Solaris System Manager from Munich, Germany
I used to work for Sun Microsystems Support (EMEA) for 5 years

 

[mheloy]

hmmmm... from the SDS manual it says it can but there is not parity on the added disk. it also just concatenates it.
is this safe?

 

[daFranze]

no, if this disk fails data is lost...

Best Regards, Franz
--
Solaris System Manager from Munich, Germany
I used to work for Sun Microsystems Support (EMEA) for 5 years

 

[mheloy]

Hi daFranze,

Ok we will be aware of that.

I have another question, can we add a new disk smaller than the existing disk in the RAID5 configuration?

Thanks

 

[daFranze]

no, all disks must be the same size (at least the slice you use in the RAID5)

Best Regards, Franz
--
Solaris System Manager from Munich, Germany
I used to work for Sun Microsystems Support (EMEA) for 5 years

 

[mheloy]

Thanks again daFranze!

 

[mheloy]

Hi daFranze,

I encoutered an error during metattach
maxtransfer is too small

# metattach d6 c25t16d38s3
metattach: uxedm1a: c25t16d38s3: maxtransfer is too small


how can I check the maxtransfer of each devices? how can I change the maxtransfer for each device?

Thanks

 

[daFranze]

the slice you attach is smaller than the other disks; please refere to format output about the size of the other diskslices...

Best Regards, Franz
--
Solaris System Manager from Munich, Germany
I used to work for Sun Microsystems Support (EMEA) for 5 years

 

[mheloy]

Format output of new disk

Primary label contents:

Volume name = < addhome>
ascii name = <SUN18G cyl 7506 alt 2 hd 19 sec 248>
pcyl = 7508
ncyl = 7506
acyl = 2
nhead = 19
nsect = 248
Part Tag Flag Cylinders Size Blocks
0 unassigned wm 0 0 (0/0/0) 0
1 unassigned wu 0 0 (0/0/0) 0
2 backup wm 0 - 7505 16.86GB (7506/0/0) 35368272
3 unassigned wm 0 - 7503 16.86GB (7504/0/0) 35358848
4 unassigned wm 0 0 (0/0/0) 0
5 unassigned wm 0 0 (0/0/0) 0
6 unassigned wm 0 0 (0/0/0) 0
7 unassigned wm 0 0 (0/0/0) 0


Format out of existing disk

Primary label contents:

Volume name = < >
ascii name = <SUN18G cyl 7506 alt 2 hd 19 sec 248>
pcyl = 7508
ncyl = 7506
acyl = 2
nhead = 19
nsect = 248
Part Tag Flag Cylinders Size Blocks
0 unassigned wm 0 - 7505 16.86GB (7506/0/0) 35368272
1 unassigned wm 0 0 (0/0/0) 0
2 backup wm 0 - 7505 16.86GB (7506/0/0) 35368272
3 unassigned wm 0 - 7503 16.86GB (7504/0/0) 35358848
4 unassigned wm 0 0 (0/0/0) 0
5 unassigned wm 0 0 (0/0/0) 0
6 unassigned wm 0 0 (0/0/0) 0
7 unassigned wm 0 0 (0/0/0) 0


I'm adding the slice 3 of the new disk but I got an error when issuing "metattach d6 c25t16d38s3"
Error: maxtransfer is too small

Thanks

 

[daFranze]

can I see the prtvtoc of the existing disk in d6?

Best Regards, Franz
--
Solaris System Manager from Munich, Germany
I used to work for Sun Microsystems Support (EMEA) for 5 years