SCSI vs SATA

[JohnBee]

I am sitting at a junction between dedicated hosting offers. The two packages are both competitive however I wanted to know if the differences outweighed the other where SCSI and SATA are concerned.

Package No.1
P4 Xeon 3Ghz
Cento OS4
2GB RAM
120GB (SATA)
500GB BW

Package no.2
P4 Xeon 2.4
1GB RAM
73GB HDD (SCSI)
2000GB BW


These are aimed at serving a larger community of aproximately 4500 members with 30 - 60 simul users.

[encryption]

Sata Vs. SCSI makes a difference if your board is extremely large in size (1000+ registered members online ... not guests ... who are actively posting and server load is rocketing). It's such times where the advantage of a SCSI shines.

If you're not at this stage, get the 3Ghz machine with more RAM, you should be golden.

[nostrum]

hi

SCSI is more reliable and faster hardware than SATA.

SCSI hard drives come with 5 years warranty and they are build to work 24/7.

SATA hard drives are mostly for home use. Western Digitan make hard drives for servers (RE series) but they are also class under SCSI.

[jasonlitka]

Sata Vs. SCSI makes a difference if your board is extremely large in size (1000+ registered members online ... not guests ... who are actively posting and server load is rocketing). It's such times where the advantage of a SCSI shines.

If you're not at this stage, get the 3Ghz machine with more RAM, you should be golden.

This is only partially correct. While it's true that a board may not need SCSI or SAS if it's not very large, the point where where SCSI shows a benefit is WELL below 1000 concurrent users and it most certainly DOES include guests.

My thoughts on drive selection come down to something like what is below for a 900 second cookie. Feel free to add RAID 1 to any of the configs that don't explicitly mention RAID if you're interested in increasing uptime in the event of a drive failure.

• < 150 - 7.2K SATA
• 150-300 - 10K SATA or 10K SCSI
• 300-500 - (4) 10K SCSI in RAID 10
• 500-750 - (4) 15K SCSI in RAID 10
• 750+ - Multiple servers, RAID 1 for web servers (10K or 15K drives), RAID 10 for DB servers (15K drives)

[lnxcode]

Depends on SCSI If its 15K RPM then it will be amazing. I would say SATA is ok to be honest. Performance is great, but 15K RPM Drives or even 10K are not going to really increase it that much. Its mainly used to counter bottle necks where there is tons of requests like on a shared hosting server.

[encryption]

This is only partially correct. While it's true that a board may not need SCSI or SAS if it's not very large, the point where where SCSI shows a benefit is WELL below 1000 concurrent users and it most certainly DOES include guests.

My thoughts on drive selection come down to something like what is below for a 900 second cookie. Feel free to add RAID 1 to any of the configs that don't explicitly mention RAID if you're interested in increasing uptime in the event of a drive failure.

• < 150 - 7.2K SATA
• 150-300 - 10K SATA or 10K SCSI
• 300-500 - (4) 10K SCSI in RAID 10
• 500-750 - (4) 15K SCSI in RAID 10
• 750+ - Multiple servers, RAID 1 for web servers (10K or 15K drives), RAID 10 for DB servers (15K drives)

I respectfully disagree. I host a site that averages 500+ total users online (members and guests) on a "shared" environment and the site performs flawlessly on a SATA HD.

Even my own site in my signature averages 400+ members (at most times) and its on a SATA HD.

So I'm not sure what you're basing those numbers on.

[jasonlitka]

So I'm not sure what you're basing those numbers on.

It's based on personal experience with the dozen forums run by the company I work for. That is a similar progression to what we moved through over the past 4 years that I've worked here (with corrections for mistakes made, such as choosing RAID 5 instead of 10).

The site in your sig is currently showing 275 online users but your cookie timeout seems to be a full hour, not the 15 minutes (the default) I was referring to above. If I look at the number of active users & guests on your site for the past 15 minutes only then that 275 drops to 29, placing you in the range I mentioned was fine for a single SATA drive.

I guarantee you that if you had those 275 users on a 900 second cookie that you would NOT be OK with a single 7200RPM drive and you would be bordering on what would be fine for ANY kind of single drive.

[alemcherry]

I guarantee you that if you had those 275 users on a 900 second cookie that you would NOT be OK with a single 7200RPM drive and you would be bordering on what would be fine for ANY kind of single drive.

Haha.. I was running a forum (my clients) with 500 users on a single SATA drive server. Now it is around 1,000 users online and works nearly ok with with a SCSI(15k rpm), Dual Xeon, 4 GB ram setup. It is till growing and we are going to have a separate db server. On an avg., the user browse 16 pages. Still the speed is okay, no complaints or anything!

[Joshs]

SCSI is more reliable and faster hardware than SATA.

SCSI hard drives come with 5 years warranty and they are build to work 24/7.

SATA hard drives are mostly for home use. Western Digitan make hard drives for servers (RE series) but they are also class under SCSI.

Not completely true.

Warranty depends on the vendor.

[JohnBee]

Has anyone seen or tried the newer crop of PCIe SATA RAID controllers?

I found this one and I wondered if it was worth looking into. The thought of adding 2x 750GB drives at the cost of one SCSI 1/2 the size is very apealling.

• Type: SATA-II
• Internal Connectors: 12 Serial ATA 300
• Interface: 64-bit/66MHz PCI2.2
• RAID: RAID 0/1/5/10 JBOD
• OS Support:
• Microsoft® Windows® 2003/XP/2000
  - RedHat® Linux
  - SuSE® Linux
  - FreeBSD
• Dimensions: 6.875"(L) x 4.2"(H)

Features

• 256MB of ECC protected SDRAM, up to 1GB max
• Battery Backup Unit Ready
• Online Capacity Expansion ready
• StorSwitch point-to-point, non-blocking switched architecture for highest performance
• Bootable array support for greater fault tolerance; S.M.A.R.T. disk drive monitoring for reliability
• SMTP support for email/pager notification

[JohnBee]

I also found this one, with later generation hardware. Although it is quite pricey, it does offer some very advanced features.

• 7th-generation StorSwitch™ non-blocking switched architecture
• On-board I/O RISC processor and RAID offload provides true hardware RAID - SCSI device driver model to take advantage of the benefits of SCSI using inexpensive Serial ATA drives
• Bootable array support for greater fault tolerance
• Variable stripe size for performance tuning by application
• 64-bit LBA support
• ATA pass-through mode support
• 256 MB DDR2 400 memory with ECC protection
• 32 pooled DMA channels
• SNMP support
• SMTP support for email/pager notification
• ATA/6 and Out of band (OOB) staggered drive spin-up support
• StorSave platform for advanced performance tuning with the BBU
• Multiple logical unit sizes and RAID levels on one card
• Multiple card support within a system for large storage requirements
• Hot-swap and hot-spare support for data availability
• Dynamic sector repair for robust data protection
• Online Capacity Expansion and RAID Level Migration
• Battery Backup Unit (BBU) support
• Enhanced data protection with write journaling for non-redundant arrays and accidental drive removal
• Drive insertion and removal notification
• Array/Drive Status and drive identification LED support

I wonder if there would be any advantages to using with a 4 x 1TB SATA drives setup.

[jasonlitka]

3Ware controllers are excellent for SATA RAID and are well-supported in Linux. The latest crop of Areca controllers are a bit faster but don't work with all Linux variants (yet). I wouldn't go with anyone other than those two.