Thinking about trying a server SSD replacement...Questions.

[Ronco]

There's a Poweredge T410 that's sitting in one of our offices. It does exactly what we need out of it - but the access time could definitely be faster as there are a lot of different things going on with it. Currently it's running 4x 300Gb 15K SAS drives through a PERC H700A. It's running Windows Server 2008 R2 and at the moment this is unlikely to change.

Any replacement will need similar capacity but be appreciably faster.

What could I do in terms of changing this setup for the better? I'm assuming that if I just go and swap the drives with something like the Seagate 1200's the PERC will become the bottleneck...? And in which case, how much of a bottleneck? Is there a better way?

I'd appreciate any input.

 

[MrGuvernment]

are you sure it is I/O, have you tested throughput on it?

What kind of load is taking?

 

[Dew]

Here is what a pair of 1TB EVO 850s look like in RAID1 on a H700i:

 

[PliotronX]

We installed MX100s in a T410 (RAID-5), MX300s in a T310 (RAID-1), and BP5Es in another T310 (RAID-10). The T310s have H700s and the T410 has the slower 6i but they all perform fantastically. They are so much more joyful to maintain.

Edit- to elaborate, if a caching scheme is enabled, the PERC can become a hindrance as it will be involved in queuing commands with the drives. The H700 has an unmarked feature called Cut Through I/O which is enabled when read ahead is disabled and write cache is not set to write back. Normally with mechanical drives you want these reversed but Google for more info. Anything that is related to the disk subsystem is affected by the upgrade. Patching the os and software, database queries, tons of simultaneous SMB transfers, rebooting, imaging, virtualization (especially) etc. Highly recommended! Just as SSDs rejuvenate workstations, it does the very same for servers!

 

[Ronco]

Thanks for the posts - I'll review and make a decision.

Oh, one more set of questions:

What about TRIM? Drive wear is definitely going to be more of an issue with servers but how does e.g. consumer drives work out with server loads?

How did you guys replace a disk array with SSD? Single drive pull - rebuild, or complete backup and restore?

What about the SAS controller? I can't attach SATA SSD's to this, can I? So... do I replace with a SATA SSD controller?

 

[PliotronX]

Thanks for the posts - I'll review and make a decision.

Oh, one more set of questions:

What about TRIM? Drive wear is definitely going to be more of an issue with servers but how does e.g. consumer drives work out with server loads?

How did you guys replace a disk array with SSD? Single drive pull - rebuild, or complete backup and restore?

What about the SAS controller? I can't attach SATA SSD's to this, can I? So... do I replace with a SATA SSD controller?

TRIM is likely not supported but its not necessary. The T310s I mentioned are overprovisioned by about 1GB per NAND (virtual disks end up 8-24GB less than full capacity) for added reliability and consistent performance but the T410 has virtual disks encompassing the full capacity. These have been running for quite a while with no issues at all, not a single failure or "predictive failure" flag that happens so often to 15k drives.

The T310 with the RAID-10 was image-cloned with an intermediary SATA drive (in place of the worthless RD1000 tape drive) as its a bare metal server and the other T310 with RAID-1 just had the lone VHD it has also copied to an intermediary drive and copied back to the RAID-1 array. All of these had scheduled downtime for the projects but if uptime is important, I'm not sure how the musical drive swapping would work out.

The RAID-1 drives are in the front bays using a certain type of adapter that aligned the SSDs with the SAS connectors in the original 3.5" caddies. SATA will actually physically plug into and work fine with SAS SFF8482 connectors but not the other way around (SAS drives won't work with SATA connectors or controllers). The RAID-10 drives are in a 5.25" Icydock Express with a breakout cable:

The Icydock powers all bays from a single SATA power header. Works great and is hotswappable as well!

 

[Ronco]

SATA will actually physically plug into and work fine with SAS SFF8482 connectors but not the other way around (SAS drives won't work with SATA connectors or controllers).

Holy crap I've been using SAS drives since they came out and I had no idea of this - I thought the signalling was incompatible. Thanks for that info. I was thinking about the Seagate Enterprise SAS SSD's but I might test it with a few SSD's then move to SM863a's.

 

[olavgg]

Get enterprise grade SSD's, they are like 10-100 times faster than consumer grade SSD's for certain workloads. Consider this review with Samsung 840 Pro, which has almost identical performance to Samsung 850 Pro. It looks like a joke. http://www.storagereview.com/micron_m500dc_enterprise_ssd_review

Another example with ZFS SLOG

Intel S3500 and Intel S3700 are available almost nothing on Ebay.

 

[Ronco]

Last question for now for anyone:

What are the competibility issues I could expect to come across with an SM863a on an H700A?

 

[PliotronX]

Last question for now for anyone:

What are the competibility issues I could expect to come across with an SM863a on an H700A?

The only thing I can foresee is the H700A not seeing the physical drive to be included in a virtual disk if the firmware is not up-to-date. The pre-2014 firmware refused to work with non certified drives and Dell caught so much flak that they removed the block in later firmware. With newer firmware, its smooth sailing!

 

[Ronco]

The only thing I can foresee is the H700A not seeing the physical drive to be included in a virtual disk if the firmware is not up-to-date. The pre-2014 firmware refused to work with non certified drives and Dell caught so much flak that they removed the block in later firmware. With newer firmware, its smooth sailing!

Excellent. Off to buy some SM863a's then.

 

[PliotronX]

I'm curious and nerded out . Nothing like updating and rebooting all VMs faster than spinners doing one VM!