tundra@ux1.cso.uiuc.edu (John Kemp) (03/15/90)
*** 20 Gbyte r/w Optical JukeBox ***
Anybody know the details of this beast?
We have received the following information. Can you
verify or deny the following:
1) a discless 340 CANNOT access a 20Gb Optical drive as
a block device, or receive open/read/write/close from programs
(same person says that on a 340 with a disc, you CAN)
2) a 20Gb Optical drive can be treated "logically" as
one huge storage media, i.e. you can copy a 999Mb
to the drive without user inetervention.
We want to have a discless 340 booting off of a 835
(because it is a cheap way to get a SCSI port). But
the details are kind of fuzzy. HELP!
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--- univ of illinois (_ ( __) bitnet - {uunet,convex}tonyc@hpurvmc.HP.COM ( Tony Cox (SR) ) (03/16/90)
He//she is right. My understanding is that you cannot have a local file system running off of the discless client. I haven't heard of a fix to this in 8.0. Also, on a system I configured my understanding is that the jukebox looks like one massive 20GB device and the info on where each file is located is stored in the superblock. This is why the device wasn't supported until 7.0 where the single drive was supported at 6.5. tonyc
rocky@hpfcmgw.HP.COM (Rocky Craig) (03/28/90)
> ...my understanding is that the jukebox > looks like one massive 20GB device and the info on where each file is > located is stored in the superblock. This is not correct. You can individually mount(1M) each SURFACE of a single disk as a file system. The 7.0 driver(s) take care of grabbing the correct media, flipping it around, etc., so that access to the many filesystems is transparent (if not immediate :-) to the user. Number of disks: 32 max \ so there are up to 64 filesystems available Sides per disk: 2 / in a "loaded" autochanger Bytes per side: 325 megabytes (the maximum size for a single filesystem) 20 Gigabytes is 32 * 2 * 325 megabytes. I believe you can actually mount all 64 filesystems (but what an fsck nightmare!!!!) Rocky Craig Hewlett-Packard Workstation Group, Marketing Event Technical Support 3404 E. Harmony Road, Ft. Collins, Colorado 80525-9599 Internet: rocky%hpfcmr@hplabs.hp.com UUCP: ...!{hplabs | hpu*}!hpfcmr!rocky This article does not represent the official position of the Hewlett-Packard Company. The above data is provided for informational purposes only. It is supplied without warranty of any kind.
dlj@hpfcso.HP.COM (Dave Jobusch) (03/29/90)
/ hpfcso:comp.sys.hp / rocky@hpfcmgw.HP.COM (Rocky Craig) / 7:40 pm Mar 27, 1990 / >20 Gigabytes is 32 * 2 * 325 megabytes. I believe you can actually mount >all 64 filesystems (but what an fsck nightmare!!!!) > >Rocky Craig >Hewlett-Packard Workstation Group, Marketing Event Technical Support >3404 E. Harmony Road, Ft. Collins, Colorado 80525-9599 > >Internet: rocky%hpfcmr@hplabs.hp.com >UUCP: ...!{hplabs | hpu*}!hpfcmr!rocky > >This article does not represent the official position of the Hewlett-Packard >Company. The above data is provided for informational purposes only. It is >supplied without warranty of any kind. My group is currently using two "jukeboxes" connected to a 370 for a backup project. The scheme that our programmer is using (and I believe what the manual suggests as well) is to mount only 2 surfaces (per jukebox) read/write, and mount the rest as read-only as needed. Fsck'ing 20GB would take awhile :-) +----------------------+-----------------------------------------------------+ | ___ | David L. Jobusch | | / / | Distributed Systems Suppport | | HEWLETT/hp/PACKARD | 3404 East Harmony Road MS#68 | | /__/ | Ft. Collins, CO 80525 | | Fort Collins Site | Internet: dlj@hpfcla.hp.com | |Information Technology| Voice : 303.229.6637 | +----------------------+-----------------------------------------------------+
corrigan@weber.ucsd.edu (Michael J. Corrigan) (03/29/90)
In article <1080137@hpfcmgw.HP.COM> rocky@hpfcmgw.HP.COM (Rocky Craig) writes: >> ...my understanding is that the jukebox >> looks like one massive 20GB device and the info on where each file is >> located is stored in the superblock. > >This is not correct. You can individually mount(1M) each SURFACE of a >single disk as a file system. The 7.0 driver(s) take care of grabbing >the correct media, flipping it around, etc., so that access to the >many filesystems is transparent (if not immediate :-) to the user. Right, not immediate. It would take over 10 minutes for a df to complete on a fully loaded and mounted jukebox ( the first time through and then this info is in the disk buffer cache) > >Number of disks: 32 max \ so there are up to 64 filesystems available >Sides per disk: 2 / in a "loaded" autochanger > >Bytes per side: 325 megabytes (the maximum size for a single filesystem) > 325 Mb is "unformatted" so to speak in that you get 265 Mb per side with a 10% minfree fs, and 295 Mb if you exceed the minfree. >20 Gigabytes is 32 * 2 * 325 megabytes. I believe you can actually mount 16.6 Gb is 32 * 2 * 265 or 18.4 Gb is 32 * 2 * 295 but heck, what's a couple of gigabytes ? >all 64 filesystems (but what an fsck nightmare!!!!) Actually, not that bad: 13.3 minutes for fsck preening 64 sides, assuming they were umounted cleanly. 2.6 hours at worst assuming no nail-biting questions posed ( Unknown File Type I=2 (Clear) ?). > >Rocky Craig >Hewlett-Packard Workstation Group, Marketing Event Technical Support >Internet: rocky%hpfcmr@hplabs.hp.com >This article does not represent the official position of the Hewlett-Packard >Company. The above data is provided for informational purposes only. It is >supplied without warranty of any kind. and In article <7370110@hpfcso.HP.COM> dlj@hpfcso.HP.COM (Dave Jobusch) writes: [deleted] > >My group is currently using two "jukeboxes" connected to a 370 for >a backup project. The scheme that our programmer is using (and >I believe what the manual suggests as well) is to mount only 2 surfaces >(per jukebox) read/write, and mount the rest as read-only as needed. The manual doesn't say that. It says: "You can have as many read/write surfaces as you want: however you should minimize the number of surfaces mounted read/write [because if] ... the system's power fails, all write-mounted surfaces will require ... fsck. The time required ... could be excessive" (HP pn C1700-90000,10/12/89,page 9-6) 2 surfaces (from different disks) is the number to mount to avoid disk swaps. > >Fsck'ing 20GB would take awhile :-) > >| ___ | David L. Jobusch >| / / | Distributed Systems Suppport >| Fort Collins Site | Internet: dlj@hpfcla.hp.com Michael J. Corrigan corrigan@ucsd.edu