Experience with building file servers...

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Ry4n

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The time has come to upgrade my file server - Im currently running a Old HP Proliant ML series server with 8x 15k SCSI drives on a raid 5

I have received my new HP Proliant DL180 - but my suppier recommends 8x 1TB 7k SAS drives.
Now I dont like the fact that these drives are 7k RPM and not 15k like my old drives. I have over 500 users accessing this server on a daily basis and I dont think thoes drives are going to cut it.

My supplier can't get 1TB 15k SAS drives - I dont think they avaiable yet :confused:

Has anyone got any suggestions I need 4TB+- storage on a RAID 5 :erm:
 
How about RAID10? It will be quicker than RAID5, and you won't notice the reduced RPM speed per disk....
 
That would require me to buy another RAID Controller and a new houseing unit.

The current DL180 can only hold 8 disks.

8x 1TB on RAID 10 wont give me near 4TB :(
 
They only make 300g 15k disks.

You have to decide wether you want alot of storage or alot of IOPS. And since you call it a file server im assuming that storage is what you are after. Now if this would have been db or ESX storage i would say gogo 15k rpm.

Just buy 2 NAS/DAS chassis and accupy as needed. Or a SAN with mixed mode :-)
 
Your best bet, assuming you can't get hold of larger disks anytime soon, would be to buy an extra RAID controller and another housing unit.
 
How much ram have you got on your RAID controller? You might find that if you have 1GB RAM on the RAID card you will probably not even see the difference. Also check out the random access times for the new SAS drives comared to the old SCSI drives you are replacing. You may find that although they are slower than 15K RPM SAS drives they are still faster than the old SCSI drives. i.e. you will still have faster file access than the old file server.
 
Scavenger

Ry4n said:
Im currently running a Old HP Proliant ML series server with 8x 15k SCSI drives on a raid 5
Click to expand...

Sorry cannot help

Be interested in the old SCSI drives when you let them go ( to a good home :D )


MW
 
OK it looks like a new raid controller and a housing unit grr they pricey.
 
Last edited:
8 x 1TB RAID 10 = 4TB. RAID 10 loses 50% of the RAW disk.

Each disk is mirrored, and then each mirrored pair striped....
 
Ry4n said:
That would require me to buy another RAID Controller and a new houseing unit.
Click to expand...
Check the specs on the machine you plan on acquiring - I know that even a baby ML110 supports RAID 0, 1 and 10 out the box.
 
Is this server used mainly for write and reads or mainly one of the two?

Is this a Linux box? If so, what is the wa load?
 
Are the SAS drives the dinky little 2.5" drives? If so, their smaller diameter and higher data density may well make them a fair bit quicker than the SCSI drives.

As for array layout - I'd go for RAID5 with a hot spare, giving you 6TB. If you're more interested in high throughputs etc. you'd rather be running an HP Modular Storage Array with fibre cards, or something similar.
 
You can work out your IO requirements using your current disks as a benchmark.

Easy way:

Using Perfmon, measure Physical disk Ave Disk Queue. It should be less than the number of physical spindles. So if you currently have RAID5, with 5 disks, then the queue should be below 5....

Using perfmon measure Physical Disk Reads per Second and Physical disks Writes per second.

Apply the necessary calculation depending on your RAID level:

Raid 0 -- I/Os per disk = (reads + writes) / number of disks
Raid 1 -- I/Os per disk = [reads + (2 * writes)] / 2
Raid 5 -- I/Os per disk = [reads + (4 * writes)] / number of disks
Raid 10 -- I/Os per disk = [reads + (2 * writes)] / number of disks

If you have RAID1 with 2 disks and your reads were 100, and writes were 100, disk queue 4.
Raid0 - IO=100+100/2 = 100 IOPD

With that you can determine, using the disk manufacturer figures, the best RAID level; RAID 5 may be OK, and you get more capacity....
 
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