I've had very poor experience with flash drives as well. I've asked to order one of these: http://www.superbiiz.com/detail.php?name=SM8GN657R to see if it behaves any better, but i'm not sure when I'll get to test it. There is definitely something inside nexenta that causes thrashing of the flash disks because doing an install of ilumos or opensolaris didn't cause those issues.

Running a full blown, large Operating System like Solaris from a flash-drive is asking for it. The idea alone...

We are not in OpenFiler / FreeNAS / ESXi territory here.

My experiences are to take a bootdrive that is "memory size + 5GB". So on my 16GB box i took a notebook HD, short-stroked to 25GB. Runs the OS and the webgui is fast. I once shortstroked it to 15GB once (i made a mistake) and thus had a 15GB drive. Nexenta installed quickly but running it was slooooooooooooow.

I therefore assumed that there needs to be place for swap that is as large as the memory-size plus at least 5GB for the OS itself so it can store temp-stuff etc.

I did a test install on the USB drive, and it did run faster, but I've decided to try a couple of other options instead:

1. A 7200 rpm 2.5" SATA laptop drive

2. A 3.5" SATA drive

3. Keep the Raptor

I have several laptop drives, and I've read where people are using them for OS drives when space is an issue. I think the speed will likely be better than the CF and the USB drive, but I won't know until I give it a try.

I also have several 3.5" drives, so this will be my second choice, since it will use up a drive bay.

I'm veering away from #3, as the drive runs really hot. Sure it's fast, but since this system is not a full production system, and is primarily used for backups, the payoff in speed is really minimal compared to the cost in heat.

So, how did you short-stroke your drive? I think my laptop drive is a Hitachi, so I could probably find the Hitachi software out there, but if not, I'm not sure how to do it. Some say that simply creating a small partition on the drive and leaving the rest unpartitioned will work, but I don't think this is the case with Nexenta, as it will repartition and reformat the drive into the required partitions during the setup process.

Any advice on this would be appreciated.

Thanks!

Scott Thomas wrote:

So, how did you short-stroke your drive? I think my laptop drive is a Hitachi, so I could probably find the Hitachi software out there, but if not, I'm not sure how to do it.

I used Seagate's seatools. It's a DOS tool (make it boot from a USB stick for convenience). It can modify Seagate and WD drives without problems. Hitachi have their own tool (forgot the name though). It's basically modifying the LBA number which a drive displays to the BIOS to a much lower value that corresponds to the desired GB size.

Some say that simply creating a small partition on the drive and leaving the rest unpartitioned will work, but I don't think this is the case with Nexenta, as it will repartition and reformat the drive into the required partitions during the setup process.

That works with Windows or Linux but not with the Nexenta installer. It will not work as the installer takes all the diskspace it can on the selected drive(s)

I took two WD Caviar Black 320GB Notebookdrives as they are fast (for a notebook drive) and use very little power. I short-stroked them to 25GB and told the installer to take the two 25GB drives it detected and combine them into a mirror (Raid-1). It's bloody fast i'll tell ya.

I finally got around to doing this, and used a 120GB Hitachi drive, short-stroked to 25GB. I can't tell a difference in the performance compared to the Raptor drive, so I'm going to keep this one.

Thanks for your advice!

Scott

I had similar problems when installing/booting from a 16GB Sandisk USB flash drive, for the same reasons - wanting to free up a SATA connection for more storage.

The HP 40L server has a built-in USB connection for just this purpose

Installing from a USB CD-ROM drive, It took hours to install, which was a bad start. Similarly, rebooting and starting up took half an hour.

Once the system was booted up it was working and I could log in on the commandline, the Web GUI was noticeably slow , but the real problem was when I saw the amount of writes going to the syspool - there are writes all the time, which is severely degrading the life of the USB flash drive.

Maybe in a future release Nexenta could use a big ramdisk (initrd?) for the O/S and only read from USB Flash until changes are made, or a reboot happens, and all the changes are committed back to USB Flash..

For me, the whole problem stems from limitations in Nexenta/OpenSolaris/Nexenta

• Can not boot from RAID-Z
• Can not share a boot SSD with a Data pool as Cache/ZIL

If any of the above problems could be fixed, there may be better options than booting from USB Flash

We use a handful of products that benefit from CF and USB boot, like VOIP phone systems and Network security devices.

This is a bit more involved. In fact I sometimes run into slowdowns on a machine with older dual ATA133 IDE drives as syspool.

Rob Moss wrote:

I had similar problems when installing/booting from a 16GB Sandisk USB flash drive, for the same reasons - wanting to free up a SATA connection for more storage.

The HP 40L server has a built-in USB connection for just this purpose

Installing from a USB CD-ROM drive, It took hours to install, which was a bad start. Similarly, rebooting and starting up took half an hour.

Once the system was booted up it was working and I could log in on the commandline, the Web GUI was noticeably slow , but the real problem was when I saw the amount of writes going to the syspool - there are writes all the time, which is severely degrading the life of the USB flash drive.

Maybe in a future release Nexenta could use a big ramdisk (initrd?) for the O/S and only read from USB Flash until changes are made, or a reboot happens, and all the changes are committed back to USB Flash..

For me, the whole problem stems from limitations in Nexenta/OpenSolaris/Nexenta

• Can not boot from RAID-Z
• Can not share a boot SSD with a Data pool as Cache/ZIL

If any of the above problems could be fixed, there may be better options than booting from USB Flash

Ok. I'm gonna repeat myself one last time: "Running a full blown, large Operating System like Solaris from a flash-drive is asking for it. The idea alone...

We are not in OpenFiler / FreeNAS / ESXi territory here."

This is Solaris we are talking about. Solaris... the BIG Operating System that needs performance boot drives to function properly. Solaris would have to be slimmed down MASSIVLY to make it work like ESXi for example. Forget it. Forget about such flash-drives / CF cards. Don't even go there ! It would be the same as asking Windows 2008 Server to run from a thumb-drive / CF card...

I have to say I don't understand the concern with a raidz syspool and sharing the root drive as l2arc/zil. I've never heard a compelling argument for why syspool/rpool isn't just a mirror. It's never supposed to be that big, so why raidz? And sharing ssd's for different purposes isn't generally recommended.