Re: External hard disk testing for use with IIAB (internet in a Box) on XO based XSCE servers
For important systems, I think a USB hard drive will be a better choice than an empty enclosure. They are also often cheaper than a new empty enclosure and a new hard drive. Indeed, buying a brand-name external USB2/3 hard drive, which is invariably implemented as a SATA drive in an enclosure, is often cheaper these days than buying the exact same drive as a SATA drive. Check prices at http://newegg.com if they sell in your country. The Internet Archive, with 10+ Petabytes of spinning drives, buys hundreds of drives at a time, and these days they usually have hundreds of discarded enclosures and power supplies to recycle to local hackers. :-/ John ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: [Server-devel] External hard disk testing for use with IIAB (internet in a Box) on XO based XSCE servers
For important systems, I think a USB hard drive will be a better choice than an empty enclosure. They are also often cheaper than a new empty enclosure and a new hard drive. Indeed, buying a brand-name external USB2/3 hard drive, which is invariably implemented as a SATA drive in an enclosure, is often cheaper these days than buying the exact same drive as a SATA drive. Check prices at http://newegg.com if they sell in your country. The Internet Archive, with 10+ Petabytes of spinning drives, buys hundreds of drives at a time, and these days they usually have hundreds of discarded enclosures and power supplies to recycle to local hackers. :-/ John ___ Server-devel mailing list Server-devel@lists.laptop.org http://lists.laptop.org/listinfo/server-devel
External hard disk testing for use with IIAB (internet in a Box) on XO based XSCE servers
I have a number of 2.5 SATA drives, that I've used for I don't know how long. I put one in a startech.com external hard drive encosure model sat2510u2E. I wrote a little cron stimulated script to write, and check for file existence, and almost immediately got failures. I was using a USB hub (plugable model:USB1-HUB-AG7) with a 5v 3A wall wart powering the unit under test. Googling the ehci_hcd failure messages, I find that there are a number of longstanding issues in running these external enclosures under linux kernels, even back in 2007 and earlier. It's not clear to me yet whether these problems are disk or interface related. So I got paranoid, and connected a western digital drive (3TB self contained 3.5in SATA USB interface with wall wart PS) that has been working for me for almost 2 years. No failures in 24 hours. Then I started learning about S.M.A.R.T., which is a disk self monitoring, reporting, that most modern disk incorporate. Running smartctl, which is part of our OS, on my old disk, and the one which exhibited failures, indicates that the drive itself does not know that it is failing. I'll probably modify the included script to use smart, in the next iteration. But I thought I'd fish for any expertise within the olpc community. Are any external enclosures known to work? I have't been able to find descriptions of the chipsets that do the USB interface. George Maybe this is too simplistic: #!/bin/bash # script to check for external hard disk presence and writeability MOUNTPT=/mnt/usb0 # read a file that is always there dtm=`date` if [ ! -f $MOUNTPT/token ]; then echo $dtm failed to read $MOUNTPT/token. Writing it /root/disk.log echo this is content written at $dtm $MOUNTPT/token else echo $dtm -- success so far /root/disk.log fi # check for the absence of a file if [ -f $MOUNTPT/writeit ]; then echo $dtm -- last attempt to remove $MOUNTPT/writeit failed /root/disk.log else echo $dtm -- content of file writeit $MOUNTPT/writeit fi sync if [ -f $MOUNTPT/writeit ]; then rm $MOUNTPT/writeit else echo $dtm -- failed to write $MOUNTPT/writeit /root/disk.log fi ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: External hard disk testing for use with IIAB (internet in a Box) on XO based XSCE servers
Empty USB to SATA enclosures have a tiny adapter containing a controller and firmware. The firmware must implement the USB storage protocol on one side, and the SATA protocol on the other. It is one of those product areas where the barrier to entry is very low, the margins low, and this can lead to a wide variation in quality. Yes, I've found they vary in terms of performance, reliability, and compatibility. Many of them don't support SMART, so you'd need to query a drive using smartctl on a system with a native SATA port in order to prove whether smartctl will work through the adapter. Relying on other people's reports is a start. I recently purchased one to re-use a SATA drive, and tested it with OLPC OS and Open Firmware. It works fine, but I have not tested SMART. Manufacturer: Welland Industrial Co., Ltd. Model: ME-746E. Brand: speed master. USB Vendor/Product: 174C:5106. USB Vendor string: ASMedia. USB Device string: AS2105. USB hard drive enclosures on the other hand allow the manufacturer to eliminate an area of doubt; because they choose both the controller and the hard drive they can assure compatibility, and test at the USB storage protocol level. For important systems, I think a USB hard drive will be a better choice than an empty enclosure. They are also often cheaper than a new empty enclosure and a new hard drive. -- James Cameron http://quozl.linux.org.au/ ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
[Server-devel] External hard disk testing for use with IIAB (internet in a Box) on XO based XSCE servers
I have a number of 2.5 SATA drives, that I've used for I don't know how long. I put one in a startech.com external hard drive encosure model sat2510u2E. I wrote a little cron stimulated script to write, and check for file existence, and almost immediately got failures. I was using a USB hub (plugable model:USB1-HUB-AG7) with a 5v 3A wall wart powering the unit under test. Googling the ehci_hcd failure messages, I find that there are a number of longstanding issues in running these external enclosures under linux kernels, even back in 2007 and earlier. It's not clear to me yet whether these problems are disk or interface related. So I got paranoid, and connected a western digital drive (3TB self contained 3.5in SATA USB interface with wall wart PS) that has been working for me for almost 2 years. No failures in 24 hours. Then I started learning about S.M.A.R.T., which is a disk self monitoring, reporting, that most modern disk incorporate. Running smartctl, which is part of our OS, on my old disk, and the one which exhibited failures, indicates that the drive itself does not know that it is failing. I'll probably modify the included script to use smart, in the next iteration. But I thought I'd fish for any expertise within the olpc community. Are any external enclosures known to work? I have't been able to find descriptions of the chipsets that do the USB interface. George Maybe this is too simplistic: #!/bin/bash # script to check for external hard disk presence and writeability MOUNTPT=/mnt/usb0 # read a file that is always there dtm=`date` if [ ! -f $MOUNTPT/token ]; then echo $dtm failed to read $MOUNTPT/token. Writing it /root/disk.log echo this is content written at $dtm $MOUNTPT/token else echo $dtm -- success so far /root/disk.log fi # check for the absence of a file if [ -f $MOUNTPT/writeit ]; then echo $dtm -- last attempt to remove $MOUNTPT/writeit failed /root/disk.log else echo $dtm -- content of file writeit $MOUNTPT/writeit fi sync if [ -f $MOUNTPT/writeit ]; then rm $MOUNTPT/writeit else echo $dtm -- failed to write $MOUNTPT/writeit /root/disk.log fi ___ Server-devel mailing list Server-devel@lists.laptop.org http://lists.laptop.org/listinfo/server-devel
