Recommends for Retired EMC Isilion x400

Status
Not open for further replies.

SweetAndLow

Sweet'NASty
Joined
Nov 6, 2013
Messages
6,421
Write
dd if=/dev/zero of=img.test bs=4k count=10000000000000
42369433+0 records in
42369432+0 records out
173545193472 bytes transferred in 402.148444 secs (431545108 bytes/sec)

173.5 GB file in 6.7 minutes
3.5 GB Per second

Each disk can write at about 3.3 M per second x 17 in the Stripe. Math seems to work out about right

Read

dd of=/dev/zero if=img.test bs=4k count=10000000000000
28217056+0 records in
28217056+0 records out
115577061376 bytes transferred in 145.448422 secs (794625749 bytes/sec)

115.6 GB file in 2.5 minutes
6.4 GB per second

I think your units and math is off. I see that as 431MB/s write and 794MB/s read.
 

Donny Davis

Contributor
Joined
Jul 31, 2015
Messages
139

Donny Davis

Contributor
Joined
Jul 31, 2015
Messages
139
I am now looking for a suitable slog. I have two samsung sm951s for l2arc. Would these be better put to use as slog? They are only 128g drives. Sync writes are important.
 

jgreco

Resident Grinch
Joined
May 29, 2011
Messages
18,680
I am now looking for a suitable slog. I have two samsung sm951s for l2arc. Would these be better put to use as slog? They are only 128g drives. Sync writes are important.

No, they'd be relatively pointless as SLOG devices. The point of a SLOG is to guarantee that the system has a place to recover sync writes that didn't actually get flushed to the pool in a transaction group (power loss, crash, etc). Since most speed-oriented consumer SSD's, and every M.2 SSD, lack power loss protection, these are unsuitable choices for a SLOG and you're better off just leaving sync writes disabled.

Suitable devices might include drives such as the Intel 750 400GB or DC P3700 (NVMe), the Intel DC S3500 or S3710 (2.5" SATA), Samsung 845DC Evo or Pro, etc. Be sure to pick one that's suitable to your pool write level.
 

Mirfster

Doesn't know what he's talking about
Joined
Oct 2, 2015
Messages
3,215
Intel DC S3500
So regarding this, would it work as desired connected directly to a SATA Port? No need for any type of considerations about a BBU, etc? Say I was looking at this or this or this...

S3710 (2.5" SATA)
What about this ?

Edit: Okay, that one is "Marked as Engineering Samples"... So maybe not that particular one...

Excuse my ignorance, just looking to quell my hardware addiction and improve stuff at the same time.

P.S. Going back to read "Some insights into SLOG/ZIL with ZFS on FreeNAS".... again... ;)
 
Last edited:

jgreco

Resident Grinch
Joined
May 29, 2011
Messages
18,680
So regarding this, would it work as desired connected directly to a SATA Port? No need for any type of considerations about a BBU, etc? Say I was looking at this or this or this...

What about this ?

Edit: Okay, that one is "Marked as Engineering Samples"... So maybe not that particular one...

Excuse my ignorance, just looking to quell my hardware addiction and improve stuff at the same time.

P.S. Going back to read "Some insights into SLOG/ZIL with ZFS on FreeNAS".... again... ;)

I wouldn't get too worried about "ES" SSD's. The point of the SLOG device is mostly to soak up a steady stream of writes, and to have power loss protection in the event of a failure. Intel mastered this stuff years ago. Their focus for engineering probably trends more towards performance under stress.

The non-NVMe SSD's I mentioned are all SATA SSD's and will be fine, probably even *best*, attached to a mainboard SATA port. In general, although we like HBA's around here, performance of an SSD attached to an HBA is a little lower than that of a directly connected SSD. That's because there's some additional time involved in traversing the HBA's CPU/controller/etc.
 

Mirfster

Doesn't know what he's talking about
Joined
Oct 2, 2015
Messages
3,215

jgreco

Resident Grinch
Joined
May 29, 2011
Messages
18,680
Huh as in a "Cool" or "Fool"?

As in I'm perplexed about what you intend to do with all that. Not that I think it's necessarily bad. I hope you got a really good price on the S3500's, because they're at a weird tier of expensive/endurance. The S3710's are insane beasts and worth every penny if you have heavy write loads, but most of the time I find storage systems have large amounts of data at rest and just moderate access patterns, so I opted out of the "buy DC grade SSD's for everything" strategy years ago. I've got Intel 535's in RAID1 for most light duty SSD storage out at the data center and then I use DC S3710 for stuff that's really whomped on. Ironically I use HDD for intermediate tier high endurance low performance storage.

But generally speaking, even though the 535's are rated 40GB/day 5 year, the DC S3500 is only rated (based on 280TBW @ 480GB size, 5 years) around 150GB/day. So those were selling for around $350 last fall, and the 535's were selling for $150, so I had a real hard time figuring out a good reason not to go with the 535's and let them burn through their endurance in a shorter period, and then replace them. If they failed.

It's impossible to tell "cool" vs "fool" for either me or you, but the numbers I'm seeing on the 535's for write loads imply we're under the 40GB/day mark so I think I saved some money. Only time will tell.
 

Mirfster

Doesn't know what he's talking about
Joined
Oct 2, 2015
Messages
3,215
Well, I paid a total of $190.00 for the four DC S3500s (160 GB each) so I guess that is a decent price; but will depend on what the SMART tests show me once they arrive. As far as the DC S3710 ($129.00 for NEW 200 GB unit), not 100% sure but leaning towards trying it out as a SLOG for FreeNas on my ESXi testing.

I appreciate the input and guidance.
 

cyberjock

Inactive Account
Joined
Mar 25, 2012
Messages
19,525
Well, I paid a total of $190.00 for the four DC S3500s (160 GB each) so I guess that is a decent price; but will depend on what the SMART tests show me once they arrive. As far as the DC S3710 ($129.00 for NEW 200 GB unit), not 100% sure but leaning towards trying it out as a SLOG for FreeNas on my ESXi testing.

I appreciate the input and guidance.

Dayum! I need to buy some S3500s at that price!
 

Mirfster

Doesn't know what he's talking about
Joined
Oct 2, 2015
Messages
3,215
Every once in a while eBay gives up some nuggets. But, will have to see how the drives turn out in testing to be sure if it was a deal or not. Just got the DC S3710 in the mail today (seller shipped it fast); so will get to testing that out soon.
 

Mirfster

Doesn't know what he's talking about
Joined
Oct 2, 2015
Messages
3,215

Donny Davis

Contributor
Joined
Jul 31, 2015
Messages
139
I grabbed some too.

Once again, this community is a wealth of wisdom. Thanks everyone for your help.

For anyone interested I have my stuff up on the public internet. You can get a couple ipv6 vms for zero dollars.

The performance of these two storage servers is quite public. Now if I could only get xisystems to cough up the code(I will give my commits back and test) for their cinder driver I would be a truly happy camper.
 
Status
Not open for further replies.
Top