Emmanuel Computer Consulting, L.L.C.

PERC S300 – can it be made to work?.

I saw this on the Dell Linux mailing list.  I did a bit of research and found this is a windows only FAKERAID product.  What I mean by FAKERAID is the card fakes like it is a raid card but all of the work is done on the cpu.  Because of this the driver is proprietary and in this case windows only.  If you want a RAID card make sure it is really a hardware raid card.  If you can’t spend that kind of money use the Linux built in RAID which is much more efficient than any FAKERAID.  Windows also has software raid that’s quite a bit more efficient than this FAKERAID.  If you read the pdf you’ll see that htis is actually a DESKTOP product(the h55 is a desktop chipset form Intel) so it really has no business in servers.  PDF detailing the S Series is here.

SSD’s are so fast that if you use more than one SSD(which you have to for ANY RAID) you may just hit a wall due to the RAID controllers not being fast enough to keep up.  What’s interesting is at one point they went to purely software RAID and saw the kind of speed increases they knew they should have been seeing.  RAID cards used to be a bottleneck but they got much much faster than any magnetic drive or groups of magnetic drives could get to…now they are once again the bottleneck.  I wonder how long it’s going to take for the RAID card manufacturers to catch up?

Here’s a three part article about SSD’s from an enterprise point of view.  It’s a good series.  Part 1, Part 2, Part 3. The author has other articles as well here, here, here.

SSD versus Enterprise SAS and SATA disks – AnandTech :: Your Source for Hardware Analysis and News.

The SSD Anthology: Understanding SSDs and New Drives from OCZ – AnandTech :: Your Source for Hardware Analysis and News.

I don’t know why I didn’t blog this last year.  It’s becoming more and more relevant though as folks start diving into SSD’s without realizing the major differences between SSD’s and mechanical hard disks.

ZFS – Wikipedia, the free encyclopedia.

I am going to look into this more.  This feature alone would allow storage admins to better utilize storage space.  Right now it’s only available on FreeBSD 8.0 and Solaris.  I may have to fire up a BSD VM on a dedicated drive set to learn how to utilize this technology.  Right now it’s CLI only..no gui(that i know of) to make things “easier”..:)

AMD Does RAID On a Chip – www.enterprisestorageforum.com.

This thing is FRAID or software raid.  It’s no better than ICHx or any other chipset based “raid” system.   When you see somehting like this:

Dot Hill’s RAIDCore technology enables host-based RAID 0, 1, 5, 10 and 50 directly on motherboard SATA I/O ports, and the same software stack with additional features enabled may also be used for SAS systems that use a built-in or PCIe host adapter-based SAS/SATA chipset.

Also a bit a googling reveals a small thread where I already researched this:

http://www.opensubscriber.com/message/centos@centos.org/1580168.html

The host based is what gives it away.  Anything that is host based puts the processing load on your cpu.  In the case of RAID 5 or 6 that load is high. Never turn this garbage on..use a real RAID controller.

Channelweb Connect: SMB Channel Voice: SMB Storage Challenges – Two Nice MS Utilities.

The Search Server Express is one thing i like.  It allows you to have your server index by content everything on your server including PDF’s.  This is one i am going to look into for all of my clients.

I reccommended to my Mother in Law that a netbook would be perfect for her based on her needs.  It IS perfect except she is running out of room on the 8 gig SSD.  I went to find an upgrade for her SSD and found one by a company called Runcore.  Let’s jsut say 160 bucks later and 5 days of pain the SSd is not bootable…the mini simply refuses to detect the drive.  This is apparently a widespread issue which I jsut found out about.  Unfortunatly returns look like a 15% hit.  Lovely.

This is why when I recommend a product it’s only after it’s been out for a while.  I will not deviate from that again.

SSDs, pNFS Will Test RAID Controller Design – www.enterprisestorageforum.com.

Current RAID controllers(real raid controllers not fake ones) are going to start hitting a serious bottleneck before too long.  Once SSD’s start getting into the market it’s not going to be how many requests but how fast you can transfer the data because with SSD’s the request is nearly instantly fulfilled.  SSD”s are going to bring in bandwidth problems fully to the forefront for the first time in decades…let’s hope the storage vendors are ready.

Many folks have not realized that modern filesystems in Windows negate the need for partitions. Back in the 16 bit days when partitions could not exceed 2 gigs or less this was necessary.  Partitioning is a throwback to dos and in the modern file systems this is actually a hindrance. Partitioning modern hard disks with modern filesystems is a waste of space and incurs a performance hit. Also considering that nearly everything you do on a windows system generates data on the system partition over time it is going to grow.  Also you lose disk space due to partitioning now. NTFS uses much smaller clusters than FAT32. When you chop the disk up the space you lose due to formatting the new partition cancels whatever benefit there may be to doing a partition in terms of disk space. What partitioning does now is now you have 1 MFT per partition. The MFT is the master file table which is basically a database of where all the files are located on the partition. Every partition you put on the disk gives you another MFT to worry about. This also introduces a performance overhead since if you access partition 2 on drive one the hard drive has to head to the second MFT, look it up, and then go find the file. Also if you copy a file from partition one 2 partition 2 now the system has to physically move the bits from one partition to the other partition on the same drive AND update two MFT’s. If everything is on the same partition then moving the files is merely a function of updating the one MFT and it’s done. The performance gain is not trivial. Try moving a gigabyte of files on a partitioned drive between partitions and then do it on a non-partitioned drive. The difference is night and day. Now if you want multiple drive letters don’t partition.  Instead setup another array either on  the same controller or preferably on another controller. Sticking with one partition simplifies things greatly:

1.  no extra drive letters to manage during system administration and most importantly during system recovery
2.  no disk space loss overhead from partitioning and formatting of partitions
3.  No performance hits from the hard drive(s) having to cross logical boundaries due to the fact that even if you specify things  like exchange and sharepoint onto a different partitions on the same physical disk something is still kept and used often on the c: partition(drive).

I have spent the past few days working with level .5 techs(in terms of the knowledge of their own product) trying to get carbonite to restore the data it so willingly allowed me to upload.  Nowhere on the site does it mention a 50 gig cap and then they slow you down below dialup speeds.  Nor do they tell you that once the restore goes bad it’s going to take tons and tons of e-mails with you getting canned non-helpful suggestions.  Only after i finally uninstalled carbonite and contacted the CEO and started posting my negative reviews did they FINALLY give me some advanced things to try..by this time i was done and was working on my recovery from the .vhd file.

I just got an e-mail from carbonite..they ahve given me a full refund and have kept the account active..I can’t trust my data to them so it’s going to be an empty sheel from now on.